Documentation of Radiometry

PROJECT REPORT ON

MICROCONTROLLER BASED

RADIOMETRIC DENSITY GAUGE

SUBMITTED IN PARTIAL FULLFILLMENT OF

THE REQUIREMENT FOR THE AWARD OF THE DEGREE OF

BACHELOR OF TECHNOLOGY IN ELECTRONICS AND

COMMUNICATION ENGINEERING

BY

D.SUDHEER KUMAR (05L01A0448)

U.HARISH (05L01A0418)

G.SUKUMAR (05L01A0449)

L.SREENATH REDDY (05L01A0444)

UNDER THE ESTEEMED GUIDANCE OF

I.C.S.REDDY, Technical Manager

NUCLEAR INSTRUMENTATION SECTION,

INSTRUMENTS AND SYSTEMS DIVISION,

ELECTRONICS CORPORATION OF INDIA LIMITED,

HYDERABAD.

ELECTRONICS CORPORATION OF INDIA LIMITED

A Govt. of India (Department of Atomic Energy) Enterprise

Instruments and Systems Division

ECIL (P.O.)

Hyderabad - 500 062 (AP)

Tel: 040 27122986

Fax: 040 27121611 E-mail: [email protected]

CERTIFICATE

This is to certify that students of 4 th year B.TECH (Electronics and

Communication Engineering) studying in TRR COLLEGE OF

ENGINEERING ,PATANCHERU affiliated to JAWAHARLAL NEHRU

TECHNOLOGICAL UNIVERSITY, HYDERABAD.




L.SRINATH REDDY (05L01A0444)

Have carried out an industry-oriented project titled “MICRO

CONTROLLER BASED RADIOMETRIC DENSITY GAUGE” at ELECTRONICS

CORPORATION OF INDIA LIMITED (ECIL), HYDERABAD. For the partial

fulfillment of requirement for the award of the industry oriented project of BACHELOR

OF TECHNOLOGY.

The project work has been completed to our satisfaction. This is the record of

Bonafide work carried out under our supervision.

PROJECT INCHARGE PROJECT GUIDE

R.S.MURTHY I.C.S.REDDY

(Sr. DGM, I.S.D) (Technical Manager)

ACKNOWLEDGEMENTS

OUR SINCERE THANKS TO OUR COLLEGE,

PRINCIPAL AND LECTURERS

WHO HAD GIVEN US THIS OPPORTUNITY.

OUR HEART FULL THANKS TO ISD-ECIL FOR

GUIDING US AT EVERY STAGE OF

THE PROJECT WORK.

THANKS TO ALL THE PEOPLE WHO HAD

HELPED US IN MAKING THIS PROJECT

A SUCCESS.

THANK YOU VERY MUCH,




L.SRINATH REDDY (05L01A0444)

COMPANY PROFILE

Electronics has been the single largest contributor to the tremendous

technical progress made in 20th century. BARC undertook the design development

and production of electronic components, instruments and systems.

This group grew in strength and diversified its activities to manufacturing

and supply of electronic equipment for the nuclear research project at Trombay.

In August 1963, the Govt. of India realizing the importance of electronics in the

process of technological development constituted the electronic committee,

familiarly known as BABA committee with late Dr. Homi Jahangir Baba as its

chairman to access the nations requirement of electronic components and

equipment and to suggest measures necessary to achieve self sufficiency in the

shortest possible time.

It was fit to undertake production on the commercial scale by converting

the electronic production division of BARC into a separate organization. This lead

to the setting up of ECIL in April 1967 as a Govt. of India enterprise, under the

development of Atomic Energy, to indigenously manufacture electronic

components, instrument and systems.

ECIL’s area of operation includes control instruments and systems, computers,

electronic components and special products for nuclear and measuring electronic

instruments and systems, defense products, color and B&W T.V, receivers,

antenna systems and consumer electronic, communication equipments. It caters to

the special requirements of nuclear and thermal power plants, telecommunication,

radio and T.V. broadcasting, police & paramilitary organization, civil aviation,

research and teaching institution in addition to consumers.

ECIL’s activities are organized into six different groups

Computer

Communication Systems

Strategic electronics

Instruments

Components and special products

Industry and consumer Electronics

ECIL lays constant emphasis on R&D, which is an essential part of any

electronic industry where the rate of obsolescence is very rapid. ECIL has a

network of four zonal offices and branches through out the country, which looks

after the sales and services function the offices, are located in CHENNAI,

MUMBAI, DELHI and KOLKATA.

ABSTRACT

The coal finds wide application in industries because of their

abundance and low cost. Coal obtained from mines consists of lot of

impurities in the form of rock. For industrial purpose, the need of high-grade

coal (with density of 1.2 to 1.5gm/cc) is essential. “Floating Technique”

obtains the high-grade coal. This technique employs washing of mine-coal in

a mixture of water and magnetite powder known as “Slurry”. Slurry has a

density of approximately 1.5gm/cc to 1.9gm/cc. The high-grade coal will

float and the coal with impurities will sink. Thus separating the high-grade

coal from the low-grade coal.

The quality of coal depends on the density of the slurry; hence

the density of the slurry should be monitored on L.C.D and the information is

sent to the control disc through the serial port and controlled continuously.

For this purpose the slurry is made to flow through a pipe to which the

“Radiometric Density Gauge” is mounted. A radioactive source and a

detector are placed on the either side of the pipe. The radiation emitted by the

source passes through the pipe and falls on the detector. The detector gets

ionized and gives an output current inversely proportional to the density of

the slurry. This signal is given to the BL2100 micro controller as analog

input.

The software used to implement this is “Dynamic C”.

OBJECTIVES OF THE PROJECT

To provide an efficient and systematic control of density of the slurry, which

indirectly helps in maintaining the quality of the coal.

To stabilize the analog voltage from the detector, which is a fast changing signal.

To display the density corresponding to the voltage and provide the controlling of

the density to maintain the slurry density at the desired value.

CONTENTS

Chapter 1 Introduction

1.1 General information

1.2 Application of Density Gauge

1.3 Principle

1.4 Advantages

Chapter 2 RADIATION

2.1 Introduction

2.2 Type of Radiation

2.3 Radiation Units

2.4 Interaction of Radiation with Matter

2.5 Safety Standards

Chapter 3 System Description

3.1 Block diagram

3.2 Description

Chapter 4 BL 2100 MICRO CONTROLLER

4.1 Description

4.2 Features

4.3 Subsystems

4.4 BL2100 Pin outs

4.5 Software

4.6 Display unit

4.7 BL 2100 Function APIs.

Chapter 5 RABBIT 2000 MICROPROCESSOR

5.1 Features & Specifications

5.2 Advantages

Chapter 6 Dynamic C

6.1 Introduction

6.2 The Nature of dynamic C

6.3 Dynamic C enhancements and differences

6.4 Functions used in Dynamic C

Chapter 7 Basic program

7.1 Flow chart for the basic program

7.2 Basic program to calculate the slurry density

Chapter 8 Contribution to the project

8.1 program1: To calculate the slurry density and display the value.

8.2 program2: To display the values and transmit using serial port

8.3 program3: To calculate the density and transmit the value to other

systems only when a request is sent

Chapter 9 Future scope

Chapter 10 Conclusion

Chapter 11 References

LIST OF FIGURES

1.Block diagram of Radiometric Density Gauge.

2.BL2100 Subsystems.

3.RJ-45 Ethernet Port Pinout.

4.Analog Reference Voltage Circuit.

5.BL2100 Pinouts.

6.Block Diagram of the Rabbit Microprocessor.

7.Flow Chart for the Basic Density Program.

LIST OF TABLES

1. BL2100 Models

2. Serial communication configurations

3. System specifications

CHAPTER 1

INTRODUCTION

1.1 GENERAL INFORMATION

The Radiometric Density Gauge is designed for continuous

measurement of the density of liquids, suspensions, slurries of poured materials.

Measurement is without physical contact and is unaffected by changes of

pressure, flow rate and viscosity.

1.2 PRINCIPLE OF OPERATION

The Radiometric Density Gauge operates on the principle that Gamma

rays absorbed as a function of density expressed mathematically.

Where,

I = Actual intensity of the gamma ray

Io = Intensity measured when no coal is present

= Total mass absorption coefficient of coal

= Density of coal

X = Thickness (distance between the source and detector)

Because the source to detector distance is fixed, ‘’ is constant. Mass

absorption coefficient’’ is constant for a given process material. Therefore,

the resultant radiation, ‘I’ is only a function of process density ‘’.

Ix =Io *exp (- X)

A correct installation ensures that a change of radiation at the detector is caused

by a chance of material density in the pipe.

1.3 THEORY OF OPERATION

The beam of Gamma rays emitted by a radioactive source, generally

Cs137 or Co60 (depending on application), passes through the slurry to an

ionization chamber (detector), which converts it into output electric current. The

strength of the current depends upon the activity of the source, on a geometric

layout and on the quantity of slurry through which the rays have passed. It will

be a function of the density of the slurry so long as the volume and geometric

disposition of the material remains constant.

The intensity of the gamma rays decreases exponentially with the

thickness and the density of the absorber. Since the diameter of the pipe in

which the slurry is passed is fixed, so the absorption of the gamma rays is

proportional to the density.

In general, an ionization chamber is used as a detector. The control of

density is done using BL2100 microcontroller, which consists of a RABBIT

2000 microprocessor, which is programmed in Dynamic C.

1.4 ADVANTAGES

Online measurement.

Non-contact measurement.

Measurement of large volumes of samples.

Withstands for harsh environment.

1.5 APPLICATIONS OF DENSITY GAUGE :

Steel Industry.

Thermal Power Station.

Coal Washeries.

Aluminum Industries and soon.

CHAPTER 2

RADIATION

2.1 INTRODUCTION

Nuclear radiation is the process by which energy is transformed from

nucleus of the atoms by releasing in the form of electromagnetic wave or other particles.

Radiation ionize/excite the medium through which it passes. This ionizing radiation is

hazardous to human health. But application of radiation and isotope technology in any

field is so beneficial for mankind that radiation is a very minor component of the risks,

what every individual is facing in day to day life so it is emphasized to treat radiation

with care rather than fear.

2.2 TYPE OF RADIATION

Alpha : +ve charged particle (two protons+ two neutrons) (AM-241)

Beta : _ve charged particle (one electron) (Sr-90, Kr-85)

Neutron : a neutral particle (Am-Be, Pu-Be)

Gamma : Electromagnetic wave (Co-60, Cs-137)

2.3 RADIATION UNITS

An International Body International Commission on Radiation Units &

Measurement (ICRU) defines radiation units.

2.3.1 ACTIVITY

Number of disintegrations per unit time1 Ci(Curie) = 3.7 x 10^10 disintegration

per second New defined unit 1 Bq(Becqurel) = 1dps.

2.3.2 QUALITY FACTOR

Gamma & Beta Radiation -- 1

Proton -- 5

Alpha -- 20

Neutron Thermal(10 Kev) -- 5

Medium(10-100 Kev) -- 10

Fast(0.1-2 Mev) -- 20

2.3.3 HALF LIFE

Half life(T1/2) of a source is defined as the period of time after which activity of

the source becomes half. It is different for different sources. Ex: Cs 137-T1/2 = 30.17

years, Co 60-T1/2 = 5.3 years.

2.3.4 K-FACTOR

Exposure from 1 mCi at 1 cm distance from the source in one hour.

Ex: Cs137- 3300 mR

1Ci = 37 GBq

2.4 INTERACTION OF RADIATION(GAMMA RAY) WITH MATTER

2.4.1 PHOTOELECTRIC EFFECT:

Interaction of radiation with a bound electron of the medium as a result of

which the entire energy is absorbed and the electron is ejected from the atom.

2.4.2 COMPTON SCATTERING:

The scattering of an incident gamma ray by an orbital electron of the medium

resulting in the transfer of a fraction of gamma energy.

2.4.3 PAIR PRODUCTION:

When the incident gamma ray energy exceeds 1.02 Mev, the gamma ray is

completely absorbed and in its place an electron-positron pair is produced

2.5 SAFETY STANDARDS:

2.5.1 STORAGE:

Proper storage and documentation of inward and outgoing radioactive material is very

important. The sources should be stored, tagged with contents and activity of the sources,

in a separate room with lock and key arrangement.

2.5.2 SOURCE HANDLING:

Time, Distance and Shielding are the major points to minimize radiation

exposure while handling sources.

2.5.3 TIME:

Radiation exposure is directly proportional to working time. A minimum time

should be taken to complete the work in the radiation field.

2.5.4 DISTANCE:

Exposure is inversely proportional to the square of the distance.

2.5.5 SHIELDING:

Shielding of the material is inversely proportional to the radiations, so shielding

of high density material is to be used to keep radiation at acceptable limits.

2.5.6 DISPOSAL :

It is advisable to plan for disposal of unused radioactive material as early as

possible. These are disposed off at Bhabha Atomic Research Center (BARC), Mumbai

with a prior permission of AERB.

CHAPTER 3

SYSTEM DESCRIPTION

3.1 BLOCK DIAGRAM:

SOURCE

HOLDER

Detector Assembly

AAAAAAAAAASassembly

LCD

Display

4 to 20mA

EHT-500vdc

LVp.s

BL2100Micro-Controller

Rabbit2000Microprocessor

EHT

…….…….

…….…….

…….

…….

A to DD to A

..;;;.;;;

;;;.;;;

;;;.;;;

;;;.;;;

LEAD

Pre-Amplifier

Ionization chamber

Signal from Detector

Block diagram of Micro controller based

Radiometric Density gauge

SOURCECs 137

3.2 DESCRIPTION

The basic system consists of the following components

Frame

Source

Electronic unit

Detector unit

Control unit

Mounting saddles

3.2.1 FRAME

Frame houses the source (Cs-137) on one side and the detector (G16) on the

other side. Source holder and detector are aligned such that the collimated narrow

beam from the source holder falls on the detector. Frame is designed to keep the

detector and the source holder almost in the center of the pipe.

3.2.2 SOURCE HOLDER:

Cesium137 or Cobolt60 source (depending on the application) is used as the

radiation source. The source is housed in a source holder with lead shielding. A

shutter is provided to keep the source either open or in closed position. There is a

provision to look the source holder in both positions. The design of Source Holder

approved has been accorded by the Division of Radiological Protection, Bhaba

Atomic Research Center, Mumbai.

3.2.3 ELECTRONIC UNIT:

The unit works on 230/110V, 50Hz, AC, Full wave bridge circuit across center

tapped secondary winding of the mains transformers is used to get the rectified

DC for 15V and +5V supplies are regulated & +24V DC un regulated. An other

Transformer is to supply 24VAC to Heater control circuit.

POWER SUPPLY:

3 terminal IC regulators are used for all supplies to provide regulated DC o/p

voltages.

A 10V reference is generated from 15 volts supply, which can be adjusted for any

deviations by potentiometer on power supply PCB. This PCB contains a source

decay compensation circuit and also main process like signal suppression. The

source decay compensation circuit consists of a linear potentiometer in feed back

circuit of a stable operational amplifier. The source decay circuit connected after

the output of the varactor bridge amplifier.

As the source decays with time varactor diode amplifier output decreases. To

maintain the amplifier output , despite a decreasing input, the source decay circuit

is designed to increase the gain of operational amplifier.

LOG-AMPLIFIER:

The log linearizer circuit compensates for non- proportional absorption of

radiation by varying amount of material. The circuit is an input signal

conditioning device that ensures output linearity related to the measured variable .

The linearizer circuit acts between the original signal amplification stage and the

following suppression circuit .In this way, only the amplified detector signal is

affected. As incoming signal is an exponential functional of the material,

linearizer acts logarithmically so that the resultant output is linear. The circuit is

log amplifier with a specific transfer function of 10log Vin/1.

NOTE:For a 10V input ,9-10V output is expected.Unity gain amplifier inverts the

input signal.

EXTRA HIGH TENSION:(EHT)

This PCB contains high voltage circuit and a high input impedance pre amplifier

circuit. High voltage supply, basically a DC-to-DC converter consists of an

oscillator whose output is rectified and filtered to obtain a stable high voltage

supply for powering the detector (Ion chamber).

EHT power supplies are characterized as being able to generate some tens of

kilovolts into capacitive loads of up to a few hundred Pico farads, typically

implying total electrical energy yields of up to about 100 mJ

.

For EHT we are using oscillator, rectifier, filter & feedback for constant high

voltage. And we are using Transformer, rectifier, filter & regulator for low

voltage power supply. Regulators 7815 is for +15V, 7915 is for –15V & 7805 is

for +5V.

3.2.4 DETECTOR UNIT:

The detector is an ionization chamber, which consist of organ gas at 20ATP.

When the radiation falls on the gas present in the ionization chamber gets ionized.

Dc voltage must be applied to collect the ions before recombination of ions takes

place. If the applied voltage is high ionization gets multiplied and large signal is

produced.

IONIZATION CHAMBER:

Ionization chamber is used to get the current, which is inversely proportional to

that of density of a liquid to be measured. The air is evacuated from the envelope

and a small amount of an inert gas, such as argon, is added.

The voltage is kept below the ionization potential of the gas. Now if radiation

penetrates through the pipe and enters the envelope, it would ionize some of the

gas atoms.

The resulting negative ions go towards the anode and positive ions towards the

cathode. In their passage, the ions collide with some of the gas atoms, causing

them to be ionized in turn. This process continues till whole of the gas atoms are

ionized. Complete ionization takes place in no time. A pulse of current then flows

through the tube. This current flowing through the resistance is the output voltage.

Pre-amplifier amplifies this output pulses from the resistance.

PRE-AMPLIFIER :

The ionization chamber reacts to the changing gamma ray intensity, out putting a

small proportional current. This current typically in the Pico ampere range is fed

to a (varactor bridge amplifier) PRE-AMPLIFIER. Amplifier feed back current

develops a usable voltage across the high-meg resistor to a given input time

constant. This constant is necessary, as over a short interval of time, radiation is a

random event and the incoming signal must be integrated to minimize these

statistical effects.

HETER CONTROL:

The heater controller unit is present in the detector unit of RDG. It is an

ionization chamber, which consist of argon gas at 20 atmos. When the radiation

falls on the gas present in the ionization gas present in the chamber gets ionized.

DC voltage must be applied to collect the ions before recombination of ions takes

place. If the applied voltage is high ionization gets multiplied and large signal is

produced. The heater controller here maintains the temperature required for the

above process with the help of the heater present in it.

Block diagram of Heater Controller

The heater control circuit consists of a triac heater driver, which is controlled by

a zero crossing switch. The circuit (except for the heater and thermistor) is located

in a separate board fixed near pre-amplifier board.’V1’ is an IC zero crossing

switch which is controlled by thermistor ‘R2’. Resistor (R1+ P1), thermistor ‘R2’

and ‘V1’ form a bridge. If the thermistor temperature is less than 65 degrees (i.e.,

thermistor resistance greater than R1 + P1), V1 supplies a pulse to the triac ‘Q1’

each time the AC voltage crosses zero. As long as the temperature at the

thermistor remains below 65 degrees C, the triac conducts and supplies power to

the heater. When the temperature exceeds 65 degrees C the output pulses of ‘V1’

are inhibited and low power is supplied to the heaters. DC powers for ‘V1’ (5.5 to

7.5V) are developed from the AC at terminals 5 of ‘V1’ by an internal power

supply. Capacitor ‘C3’ is a ripple filter for the internal supply. A safety thermostat

‘F1’ (thermal fuse) is mounted on the side of the circuit board. The safety

thermostat open the AC power line when the detector temperature exceeds 60

degrees and prevents the unit from over heating if the control circuit fails.

The heater control circuit drives 200W heat. The heater is located in a single unit

wrapped around the heater housing. The control thermistor is located on the side

of the detector package, between the installation and the heater.]

3.2.5 CONTROL UNIT:

The Control unit is BL2100 Micro Controller running on Rabbit2000

Microprocessor. The signal is received from the detector & processed the

corresponding density is displayed on LCD and digital panel meter.

(a) A/D and D/A CONVERTER:

The 4-20mA,o/p from detector is in analog form. It is converted into digital form

by using analog to digital converter (A/D). Digital form of signal is essential for

micro controller based RDG.

Digital to analog converter (D/A) is used to convert digital signal from micro

controller to analog signal for external disp

(b) Software:

The software program is developed in Dynamic C language to calculate the

density of various liquids and it is displayed on LCD and Digital panel meters.

( c ) Display Unit:

The processed and calculated data from the micro-controller is displayed on the

LCD.The display unit displays both analog meter and digital display of the

density of the liquid that is measured.

3.2.6 OPERATIONAL CONTROLS:

MAINS ON SWITCH : DPST switch is used to ON the mains supply to the

instrument. Presence of mains supply is indicated

by the pilot lamp glow.

FUNCTIONS SWITCH : One pole 4 way rotator switch to select one of the

Following:

REF : The DPM indicates the o/p of preamplifier in this

stage.

MEASURE : The DPM indicates the density of the process

material.

LOW ALARM : The DPM indicates the low alarm set point.

HIGH ALARM : The DPM indicates the high alarm set point.

3.2.7 SPECIFICATIONS:

Density Range : 1.2 gm/cc to 1.99 gm/cc

Accuracy : +/- 0.01

Response Time : 20 seconds

Radioactive source : Type CS-137 (Half life: 33yrs)

Detector : Ionization chamber LND 50417

Output Signal : 4 to 20mA DC; 600 ohms max load;

Operating temperature: 0 to 50 degrees Celsius.

CHAPTER 4

BL 2100 MICRO CONTROLLER

4.1 INTRODUCTION

The BL2100 is a high-performance, C-programmable single-board

computer that offers built-in digital and analog I/O combined with

Ethernet connectivity in a compact form factor. A Rabbit 2000TM

microprocessor operating at 22.1 MHz provides fast data processing. An

optional plastic enclosure and LCD/keypad module are available, and may

be wall-mounted.

4.2 BL2100 DESCRIPTION

The BL2100 is an advanced single-board computer that incorporates the

powerful Rabbit 2000 microprocessor, flash memory, static RAM, digital

I/O ports, A/D converter inputs, D/A converter outputs, RS-232/RS-485

serial ports, and a 10Base-T Ethernet port.

4.3 BL2100 FEATURES

Rabbit 2000TM microprocessor operating at 22.1 MHz.

128K static RAM and 256K flash memory standard, may be

increased to 512K SRAM and 512K flash memory.

40 digital I/O: 24 protected digital inputs and 16 high-current

digital outputs provide sinking and sourcing outputs.

15 analog channels: eleven 12-bit A/D converter inputs, four 12-bit

D/A converter 0-10 V outputs (selected models).

One RJ-45 Ethernet port compliant with IEEE 802.3 standard for

10Base-T Ethernet protocol (selected models).

Two Ethernet status LEDs (selected models).

Four serial ports (2 RS-232 or 1 RS-232 with RTS/CTS, 1 RS-485,

and 1 CMOS-compatible programming port).

Battery-backed real-time clock.

Watchdog supervisor.

Optional backlit 122 × 32 graphic display/keypad module.

Remote program downloading and debugging capability via

RabbitLink.

Four BL2100 models are available. Their standard features are

summarized in table 3.1

Table 3.1 BL2100 Models

Feature BL2100 BL2110 BL2120 BL2130

Microprocessor Rabbit 2000 running at 22.1 MHz

Static RAM 128K

Flash Memory 256K

RJ-45 Ethernet Connector, Filter

Capacitors, and LEDsYes No

A/D Converter Inputs

(-10 V to + 10 V)Yes No Yes No

D/A Converter Outputs

(0 V to +10 V)Yes No Yes No

Rabbit Core Module Used RCM2200 RCM2300

4.4 SUBSYSTEMS

· Digital I/O

· Serial Communication

· A/D Converter Inputs

· D/A Converter Outputs

· Analog Reference Voltage Circuit

· Memory

· External Interrupts

Figure 3.1 shows these Rabbit-based subsystems designed into the

BL2100.

4.4.1 DIGITAL I/O

DIGITAL INPUTS

The BL2100 has 24 digital inputs, IN00-IN23, each of which is protected

over a range of -36 V to +36 V. The inputs are factory-configured to be

pulled up to +5 V, but they can also be pulled up to +K2 or down to 0 V in

banks of eight by changing a surface-mounted 0 resistor as shown in

Figure 9.

Figure 3.2 BL2100 Digital Inputs [Pulled Up--Factory Default]

NOTE If the inputs are pulled up to +K2, the voltage range over which

the digital inputs are protected changes to K2 - 36 V to +36 V.

The actual switching threshold is approximately 2.40 V. Anything below

this value is a logic 0, and anything above is a logic 1.

IN16-IN23 can be factory-configured as outputs for users who prefer to

have 16 inputs and 24 outputs.

DIGITAL OUTPUTS

The BL2100 has 16 digital outputs, OUT00-OUT15, which can each sink

or source up to 200 mA. Figure 10 shows a wiring diagram for using the

digital outputs in a sinking or a souring configuration.

Figure 3.3 BL2100 Digital Outputs

All the digital outputs sink and source actively. They can be used as high-

side drivers, low-side drivers, or as an H-bridge driver. When the BL2100

is first powered up or reset, all the outputs are disabled, that is, at a high-

impedance status, until the digoutConfig software function call is made.

The digoutConfig call sets the initial state of each digital output according

to the configuration specified by the user, and enables the digital outputs

to their initial status.

OUT00-OUT07 are powered by to +K1, and OUT08-OUT15 are powered

by +K2. K1 and K2 can each be up to 36 V. They don't have to be same.

All the sinking current, which could be up to 3.2 A, is returned through the

GND pins. Be sure to use a suitably sized GND and keep the distance to

the power supply as short as possible. Since there are two GND terminals

(pin 1, screw-terminal header J4, and pin 12, screw-terminal header J11),

it is highly recommend that you split the GND returns according to the

two banks of digital outputs.

For the H bridge, which is shown in Figure 11, K1 and K2 should be the

same if two digital outputs used for the H bridge are on different banks.

4.4.2 SERIAL COMMUNICATION

The BL2100 has two RS-232 serial ports, which can be configured as one

RS-232 serial channel (with RTS/CTS) or as two RS-232 (3-wire)

channels using the serMode software function call. Table 3.2 summarizes

the options.

Table 3.2 Serial Communication Configurations

ModeSerial Port

B C D

0 RS-232, 3-wire RS-232, 3-wire RS-485

1 RS-232, 5-wire CTS/RTS RS-485

The BL2100 also has one RS-485 serial channel and one CMOS serial

channel that serves as the programming port.

All four serial ports operate in an asynchronous mode. An asynchronous

port can handle 7 or 8 data bits. A 9th bit address scheme, where an

additional bit is sent to mark the first byte of a message, is also supported.

Serial Port A, the programming port, can be operated alternately in the

clocked serial mode. In this mode, a clock line synchronously clocks the

data in or out. Either of the two communicating devices can supply the

clock. The BL2100 boards typically use all four ports in the asynchronous

serial mode. Serial Ports B and C are used for RS-232 communication, and

Serial Port D is used for RS-485 communication. The BL2100 uses an

11.0592 MHz crystal, which is doubled to 22.1184 MHz. At this

frequency, the BL2100 supports standard asynchronous baud rates up to a

maximum of 230,400 bps.

RS-232

The BL2100 RS-232 serial communication is supported by an RS-232

transceiver. This transceiver provides the voltage output, slew rate, and

input voltage immunity required to meet the RS-232 serial communication

protocol. Basically, the chip translates the Rabbit 2000's CMOS/TTL

signals to RS-232 signal levels. Note that the polarity is reversed in an RS-

232 circuit so that a +5 V output becomes approximately -10 V and 0 V is

output as +10 V. The RS-232 transceiver also provides the proper line

loading for reliable communication.

RS-232 can be used effectively at the BL2100's maximum baud rate for

distances of up to 15 m.

RS-485

The BL2100 has one RS-485 serial channel, which is connected to the

Rabbit 2000 Serial Port D through an RS-485 transceiver. The half-duplex

communication uses the Rabbit 2000's PB6 pin to control the transmit

enable on the communication line.

The BL2100 can be used in an RS-485 multidrop network. Connect the

485+ to 485+ and 485- to 485- using single twisted-pair wires

(nonstranded, tinned) as shown in Figure. Note that a common ground is

Recommended.

Figure 3.4 RS-485 Termination and Bias Resistors

PROGRAMMING PORT

The RabbitCore module on the BL2100 has a 10-pin programming header.

The programming port uses the Rabbit 2000's Serial Port A for

communication, and is used for the following operations.

Programming/debugging

Cloning

Remote program download/debug over an Ethernet connection via

the RabbitLink EG2100

The programming port is used to start the BL2100 in a mode where the

BL2100 will download a program from the port and then execute the

program. The programming port transmits information to and from a PC

while a program is being debugged.

The Rabbit 2000 startup-mode pins (SMODE0, SMODE1) are presented

to the programming port so that an externally connected device can force

the BL2100 to start up in an external bootstrap mode. The BL2100 can be

reset from the programming port via the /EXT_RSTIN line.

The Rabbit 2000 status pin is also presented to the programming port. The

status pin is an output that can be used to send a general digital signal.

ETHERNET PORT

Figure shows the pinout for the Ethernet port (J2 on the BL2100 module).

Note that there are two standards for numbering the pins on this

connector--the convention used here, and numbering in reverse to that

shown. Regardless of the numbering convention followed, the pin

positions relative to the spring tab position (located at the bottom of the

RJ-45 jack in Figure 14) are always absolute, and the RJ-45 connector will

work properly with off-the-shelf Ethernet cables.

Figure 3.5 RJ-45 Ethernet Port Pinout

RJ-45 pinouts are sometimes numbered opposite to the way shown in

Figure 14.

Two LEDs are placed next to the RJ-45 Ethernet jack, one to indicate an

Ethernet link (LNK) and one to indicate Ethernet activity (ACT).

The transformer/connector assembly ground is connected to the BL2100

module printed circuit board digital ground via a 0 resistor "jumper,"

R29, as shown in Figure.

Figure Isolation Resistor R29

The factory default is for the 0 resistor "jumper" at R29 to be installed.

In high-noise environments, remove R29 and ground the

transformer/connector assembly directly through the chassis ground. This

will be especially helpful to minimize ESD and/or EMI problems.

4.4.3 A/D CONVERTER INPUTS

The single 14-channel A/D converter used in the BL2100 has a resolution

of 12 bits (models BL2100 and BL2120 only). Eleven of the 14 channels

are available externally, and three are used internally for the reference

voltages: 4.096 V (Vref), 2.048 V (Vref/2), and Analog Ground. These

internal voltages can be used to check the functioning of the A/D

converter.

The A/D converter only measures voltages between 0 V and the applied

reference voltage. Therefore, each external input has circuitry that

provides scaling and buffering. All 11 external inputs are scaled and

buffered to provide the user with an input impedance of 1 M and a range

of -10.24 V to +10.24 V.

Figure shows the buffered A/D converter inputs.

Figure 3.6 Buffered A/D Converter Inputs

The op-amp is powered from the +V supply. The 1 M and 200 k

resistors set the gain (scale factor), which is 0.2 in this case. This results in

a dynamic input range of 0.2 × 20.48 V or 4.096 V. The center point of

this range is set by the 1.707 V reference voltage. With the reference set to

1.707 V, the center point is at 0 V and the input voltage can range from -

10.24 V to +10.24 V. To maintain the best accuracy, the input range

should be limited to -10.0 V to +10.0 V.

4.4.4 D/A CONVERTER OUTPUTS

Only the BL2100 and the BL2120 models are stuffed with D/A converters.

The D/A converter outputs are buffered and scaled to provide an output

from 0 V to +10 V.

NOTE

The D/A converter output voltage depends on the original power-

supply voltage, +RAW, so if +RAW < 13 V, the maximum D/A

converter output will be +RAW - 3 V.

Figure shows the D/A converter outputs.

Figure 3.7 D/A Converter Outputs

To stay within the maximum power dissipation of the D/A converter

circuit, the maximum D/A converter output current is 10 mA per channel

for a power-supply voltage, +RAW, up to 15 V, and drops to 2 mA per

channel for a power-supply voltage of 36 V.

Figure . Maximum D/A Converter Output

Current vs. Power-Supply Voltage

4.4.5 ANALOG REFERENCE VOLTAGE CIRCUIT

Figure shows the analog voltage reference circuit.

Figure 3.8 Analog Reference Voltages

This circuit generates the 4.096 V reference voltage, which is used by the

A/D converter and by the D/A converters. This sets the operating range of

the A/D converter and the D/A converters (0-10 V). To use the full

accuracy of the A/D converter and the D/A converters, this voltage must

be accurate to the same degree.

The reference zener diode in combination with the 300 resistor form a

shunt regulator. The 4.096 V reference voltage then feeds the A/D

converter, the D/A converters, and the voltage divider composed of the 10

k and the 14 k resistors. The voltage divider generates a second

reference voltage of 1.707 V to feed the four op-amps for the buffered

A/D converter inputs.

The 2.048 V reference voltage is also used to generate the 2.5 V reference

for D-REF used in the digital output circuit.

4.4.6 MEMORY

SRAM

The BL2100 module is designed to accept 128K to 512K of SRAM

packaged in an SOIC case. The standard BL2100 modules come with

128K of SRAM.

FLASH MEMORY

The BL2100 is also designed to accept 128K to 512K of flash memory

packaged in a TSOP case. The standard BL2100 modules comes with one

256K flash memory.

A Flash Memory Bank Select jumper configuration option based on 0

surface-mounted resistors exists at header JP2 on the RabbitCore module.

This option, used in conjunction with some configuration macros, allows

Dynamic C to compile two different co-resident programs for the upper

and lower halves of the 256K flash in such a way that both programs start

at logical address 0000. This is useful for applications that require a

resident download manager and a separate downloaded program. See

Application Note 218, Implementing a Serial Download Manager for a

256K Flash, for details.

4.4.7 EXTERNAL INTERRUPTS

The BL2100 is already configured to support external interrupts on pin 11

of screw terminal header J11. The external interrupt circuit is shown in

Figure.

Figure 3.9 Use of Rabbit 2000 External Interrupt

In addition to its primary use as an external interrupt, pin 11 of screw

terminal header J11 may also be used as a CMOS-level digital input or

output, or to generate a PWM signal.

4.5 BL2100 PINOUTS

The BL2100 pinouts are shown in Figure 3.10

Figure 3.10 BL2100 Pinouts

4.6 SOFTWARE

The BL2100 is programmed using version 7.06 or later of Z-World's

Dynamic C Premier, an integrated development environment that includes

an editor, a C compiler, and a debugger. Library functions provide an

easy-to-use interface for the BL2100. Software drivers for TCP/IP, I/O,

and serial communication are included with Dynamic C Premier.

4.7 DISPLAY UNIT

Plastic enclosure (can be wall-mounted or panel-mounted) with

LCD/keypad module that comprises a 122 × 32 LCD graphic

display, 7-key keypad, and seven LEDs. The plastic enclosure

consists of a base and a cover for an assembly made up of the

BL2100 with the LCD/keypad module plugged in.

Plastic enclosure base.

LCD/keypad module.

4.8 BL2100 FUNCTION APIS

4.8.1 Board Initialization

void brdInit (void);

Call this function at the beginning of your program. This function

initializes the system I/O ports and loads all the A/D converter and D/A

converter calibration constants from flash memory into SRAM for use by

your program. If the LCD/keypad module is installed, this function will

turn off LED DS1 to indicate that the initialization was successful.

4.8.2 Digital I/O

void digOutConfig(unsigned int outputMode);

Each of the BL2100 high-current outputs (OUT00-OUT15) has the

capability of being configured in software as either sinking or sourcing

using the digOutConfig function. Execute digOutConfig at the start of

your application to initially set OUT00-OUT15 to be OFF for the type of

circuit that you have, either sinking or sourcing.

NOTE The brdInit function must be executed before calling digOutConfig.

NOTE

You must execute the digOutConfig function to set the high-current

drivers to be either sinking or sourcing. A runtime error will occur in

digOut if digOutConfig has not executed.

NOTE

The extra digital outputs resulting from the reconfiguration of IN16-IN23

as digital outputs are sinking outputs only and cannot be configured with

digOutConfig.

PARAMETER

outputMode is a 16-bit parameter where each bit corresponds to one of the

following high current outputs.

Bit 15 = high-current output channel OUT15
















The high-current outputs can be configured to be sinking or sourcing

outputs by setting the corresponding bit to an 0 or 1: 0 = sinking, 1 =

sourcing.

RETURN VALUE

None.

outputMode = 0x0ff1; // Outputs OUT15-OUT12 =

Sinking

// Outputs OUT11-OUT08 =

Sourcing


Sourcing


Sinking

// Output OUT00 = Sourcing

int digIn(int channel);

Reads the state of an input channel.

A run-time error will occur for the following conditions:

1. channel out of range.

2. brdInit was not executed before executing digIn.

PARAMETER

channel is the input channel number (0-23)

RETURN VALUE

The state of the input (0 or 1).

4.8.3 Serial Communication

Library files included with Dynamic C provide a full range of serial

communications support. The RS232.LIB library provides a set of circular-buffer-

based serial functions. The PACKET.LIB library provides packet-based serial

functions where packets can be delimited by the 9th bit, by transmission gaps, or

with user-defined special characters.

int serMode(int mode);

User interface to set up BL2100 serial communication lines. Call this

function after serXOpen().

PARAMETER

mode is the defined serial port configuration.

ModeSerial Port

B C D

0 RS-232, 3-wire RS-232, 3-wire RS-485

1 RS-232, 5-wire CTS/RTS RS-485

RETURN VALUE

0 if valid mode, 1 if not.

4.8.4 A/D Converter Inputs

int anaIn(unsigned int channel);

Reads the state of an A/D converter input channel.

PARAMETER

channel is the A/D converter input channel (0-10) to read.

RETURN VALUE

A value corresponding to the voltage on the analog input channel ( 0-

4095).

float anaInVolts(unsigned int channel);

Reads the state of an A/D converter input channel and uses the previously

set calibration constants to convert it to volts.

4.8.5 D/A Converter Outputs

void anaOut(unsigned int channel, unsigned int rawcount);

Sets the voltage of a D/A converter output channel.

PARAMETERS

channel is the D/A converter output channel (0-3).

rawcount is a data value corresponding to the voltage desired on the output

channel (0-4095).

RETURN VALUE

0 if sucessful.

-1 if rawcount is more than 4095.

4.8.6 LCD/Keypad Module Function APIs

LEDs

When power is applied to the LCD/keypad module for the first time, the

red LED (DS1) will come on, indicating that power is being applied to the

LCD/keypad module. The red LED is turned off when the brdInit function

executes.

One function is available to control the LEDs, and can be found in the

BL21XX.LIB library.

void ledOut(int led, int value);

LED on/off control. This function will only work when the LCD/keypad

module is installed on the BL2100.

PARAMETERS

led is the LED to control.

0 = LED DS1

1 = LED DS2

2 = LED DS3

3 = LED DS4

4 = LED DS5

5 = LED DS6

6 = LED DS7

value is the value used to control whether the LED is on or off (0 or 1).

0 = off

1 = on

RETURN VALUE

None.

4.8.7 LCD Display

The functions used to control the LCD display are contained in the

GRAPHIC.LIB library located in the Dynamic C DISPLAYS/GRAPHIC

library directory.

void glInit(void);

Initializes the display devices, clears the screen.

RETURN VALUE

None.

void glBackLight(int onOff);

Sets the intensity of the backlight, if circuitry is installed.

PARAMETER

: onOff reflects the low to high values (typically 0 to 255, depending on

the board design) to set the backlight intensity (0 will turn the backlight

off completely.)

RETURN VALUE

None.

void glDispOnOff(int onOff);

Sets the LCD screen on or off. Data will not be cleared from the screen.

PARAMETER

onOff turns the LCD screen on or off

1--turn the LCD screen on

0--turn the LCD screen off

RETURN VALUE

None.

void glXFontInit(fontInfo *pInfo, char pixWidth, char pixHeight,

unsigned startChar, unsigned endChar, unsigned long xmemBuffer);

Initializes the font descriptor structure, where the font is stored in xmem.

Each font character's bitmap is column major and byte-aligned.

PARAMETERS

*pInfo is a pointer to the font descriptor to be initialized.

pixWidth is the width (in pixels) of each font item.

pixHeight is the height (in pixels) of each font item.

startChar is the value of the first printable character in the font character

set.

endChar is the value of the last printable character in the font character set.

xmemBuffer is the xmem pointer to a linear array of font bitmaps.

RETURN VALUE

None.

4.8.8 Printing the string

void glPrintf(int x, int y, fontInfo *pInfo, char *fmt, ...);

Prints a formatted string (much like printf) on the LCD screen. Only the

character codes that exist in the font set are printed, all others are skipped.

For example, '\b', '\t', '\n' and '\r' (ASCII backspace, tab, new line, and

carriage return, respectively) will be printed if they exist in the font set,

but will not have any effect as control characters. Any portion of the

bitmap character that is outside the LCD display area will be clipped.

PARAMETERS

x is the x coordinate (column) of the upper left corner of the text.

y is the y coordinate (row) of the upper left corner of the text.

*pInfo is a font descriptor pointer.

*fmt is a formatted string.

... are formatted string conversion parameter(s).

EXAMPLE

glprintf(0,0, &fi12x16, "Test %d\n", count);

RETURN VALUE

None.

4.8.9 Keypad

The functions used to control the keypad are

contained in the KEYPAD.LIB library located in the

Dynamic C KEYPAD library directory.

void keyInit(void);

Initializes keypad process

RETURN VALUE

None.

void keyProcess(void);

Scans and processes keypad data for key assignment, debouncing, press

and release, and repeat.

NOTE This function is also able to process an 8 × 8 matrix keypad.

RETURN VALUE

None

char keyGet(void);

Get next keypress

RETURN VALUE

The next keypress, or 0 if none

int keyUnget(char cKey);

Push keypress on top of input queue

PARAMETER

cKey

RETURN VALUE

None.

void keypadDef();

Configures the physical layout of the keypad with the desired ASCII

return key codes.

Keypad physical mapping 1 × 7

0 4 1 5 2 6 3

['L'] ['U'] ['D'] ['R']

['-'] ['+'] ['E']

where

'E' represents the ENTER key

'+' represents

'-' represents

'D' represents Down Scroll

'U' represents Up Scroll

'R' represents Right Scroll

'L' represents Left Scroll

Example: Do the following for the above physical vs. ASCII return key

codes.

keyConfig ( 3,'R',0, 0, 0, 0, 0 );

keyConfig ( 6,'E',0, 0, 0, 0, 0 );

keyConfig ( 2,'D',0, 0, 0, 0, 0 );

keyConfig ( 4,'-',0, 0, 0, 0, 0 );

keyConfig ( 1,'U',0, 0, 0, 0, 0 );

keyConfig ( 5,'+',0, 0, 0, 0, 0 );

keyConfig ( 0,'L',0, 0, 0, 0, 0 );

Characters are returned upon keypress with no repeat.

RETURN VALUE

None.

CHAPTER 5

RABBIT 2000 MICROPROCESSOR

5.1 INTRODUCTION

Rabbit Semiconductor was formed expressly to design a a better

microprocessor for use in small and medium-scale controllers. The first

product is the Rabbit 2000 microprocessor. The Rabbit 2000 designers

have had years of experience using Z80, Z180 and HD64180

microprocessors in small controllers. The Rabbit shares a similar

architecture and a high degree of compatibility with these

microprocessors, but it is a vast improvement.

The Rabbit has been designed in close cooperation with Z-World, Inc., a

long-time manufacturer of low-cost single-board computers. Z-World's

products are supported by an innovative C-language development system

(Dynamic C). Z-World is providing the software development tools for the

Rabbit.

The Rabbit is easy to use. Hardware and software interfaces are as

uncluttered and are as foolproof as possible. The Rabbit has outstanding

computation speed for a microprocessor with an 8-bit bus. This is because

the Z80-derived instruction set is very compact and the design of the

memory interface allows maximum utilization of the memory bandwidth.

The Rabbit races through instructions.

Traditional microprocessor hardware and software development is

simplified for Rabbit users. In-circuit emulators are not needed and will

not be missed by the Rabbit developer. Software development is

accomplished by connecting a simple interface cable from a PC serial port

to the Rabbit-based target system.

5.2 FEATURES AND SPECIFICATIONS

100-pin PQFP package. Operating voltage 2.7 V to 5 V. Clock

speed to 30 MHz. All specifications are given for both industrial

and commercial temperature and voltage ranges. Rabbit

microprocessors cost under $10 in moderate quantities.

Industrial specifications are for a voltage variation of 10% and a

temperature range from -40°C to +85°C. Commercial

specifications are for a voltage variation of 5% and a temperature

range from 0°C to 70°C.

1-megabyte code space allows C programs with up to 50,000+

lines of code. The extended Z80-style instruction set is C-friendly,

with short and fast instructions for most common C operations.

Four levels of interrupt priority make a fast interrupt response

practical for critical applications. The maximum time to the first

Instruction of an interrupt routine is about 1 µs at a clock speed of

25 MHz.

Access to I/O devices is accomplished by using memory access

instructions with an I/O prefix. Access to I/O devices is thus faster

and easier compared to processors with a restricted I/O instruction

set.

The hardware design rules are simple. Up to six static memory

chips (such as RAM and flash EPROM) connect directly to the

microprocessor with no glue logic. Even larger amounts of

memory can be handled by using parallel I/O lines as high-order

address lines. The Rabbit runs with no wait states at 24 MHz with

a memory having an access time of 70 ns. There are two clocks per

memory access. Most I/O devices may be connected without glue

logic.

The memory cycle is two clocks long. A clean memory and I/O

cycle completely avoid the possibility of tri-state fights. Peripheral

I/O devices can usually be interfaced in a glueless fashion using

pins programmable as I/O chip selects, I/O read strobes or I/O

write strobe pins. A built-in clock doubler allows ½-frequency

crystals to be used to reduce radiated emissions.

The Rabbit may be cold-booted via a serial port or the parallel

access slave port. This means that flash program memory may be

soldered in unprogrammed, and can be reprogrammed at any time

without any assumption of an existing program or BIOS. A Rabbit

that is slaved to a master processor can operate entirely with

volatile RAM, depending on the master for a cold program boot.

There are 40 parallel I/O lines (shared with serial ports). Some I/O

lines are timer synchronized, which permits precisely timed edges

and pulses to be generated under combined hardware and software

control.

There are four serial ports. All four serial ports can operate

asynchronously in a variety of customary operating modes; two of

the ports can also be operated synchronously to interface with

serial I/O devices. The baud rates can be very high--1/32 the clock

speed for asynchronous operation, and 1/6 the clock speed

externally or 1/4 the clock speed internally in synchronous mode.

In asynchronous mode, the Rabbit, like the Z180, supports sending

flagged bytes to mark the start of a message frame. The flagged

bytes have 9 data bits rather than 8 data bits; the extra bit is located

after the first 8 bits, where the stop bit is normally located, and

marks the start of a message frame.

A slave port allows the Rabbit to be used as an intelligent

peripheral device slaved to a master processor. The 8-bit slave port

has six 8-bit registers, 3 for each direction of communication.

Independent strobes and interrupts are used to control the slave

port in both directions. Only a Rabbit and a RAM chip are needed

to construct a complete slave system if the clock and reset are

shared with the master processor

The built-in battery-backable time/date clock uses an external

32.768 kHz crystal. The time/date clock can also be used to

provide periodic interrupts every 488 µs. Typical battery current

consumption is 25 µA with the suggested battery circuit. An

alternative circuit provides means for substantially reducing this

current.

Numerous timers and counters (six all together) can be used to

generate interrupts, baud rate clocks, and timing for pulse

generation.

The built-in main clock oscillator uses an external crystal or more

usually a ceramic resonator. Typical resonator frequencies are in

the range of 1.8 MHz to 29.5 MHz. Since precision timing is

available from the separate 32.768 kHz oscillator, a low-cost

ceramic resonator with ½ percent error is generally satisfactory.

The clock can be doubled or divided by 8 to modify speed and

power dynamically. The I/O clock, which clocks the serial ports, is

divided separately so as not to affect baud rates and timers when

the processor clock is divided or multiplied. For ultra low power

operation, the processor clock can be driven from the separate

32.768 kHz oscillator and the main oscillator can be powered

down. This allows the processor to operate at approximately 100

µA and still execute instructions at the rate of approximately

10,000 instructions per second. This is a powerful alternative to

sleep modes of operation used by other processors. The current is

approximately 65 mA at 25 MHz and 5 V. The current is

proportional to voltage and clock speed--at 3.3 V and 7.68 MHz

the current would be 13 mA, and at 1 MHz the current is reduced

to less than 2 mA. Flash memory with automatic power down

(from AMD) should be used for operation at the lowest power.

The excellent floating-point performance is due to a tightly coded

library and powerful processing capability. For example, a 25 MHz

clock takes 14 µs for a floating add, 13 µs for a multiply, and 40 µs

for a square root. In comparison, a 386EX processor running with

an 8-bit bus at 25 MHz and using Borland C is about 10 times

slower.

There is a built-in watchdog timer.

The standard 10-pin programming port eliminates the need for in-

circuit emulators. A very simple 10 pin connector can be used to

download and debug software using Z-World's Dynamic C and a

simple connection to a PC serial port. The incremental cost of the

programming port is extremely small.

Figure 1-1 shows a block diagram of the Rabbit.

Figure 5-1. Block Diagram of the Rabbit Microprocessor

5.3 SUMMARY OF RABBIT ADVANTAGES

The glueless architecture makes it is easy to design the hardware

system.

There are a lot of serial ports and they can communicate very fast.

Precision pulse and edge generation is a standard feature.

Interrupts can have multiple priorities.

Processor speed and power consumption are under program

control.

The ultra low power mode can perform computations and execute

logical tests since the processor continues to execute, albeit at 32

kHz.

The Rabbit may be used to create an intelligent peripheral or a

slave processor. For example, protocol stacks can be off loaded to

a Rabbit slave. The master can be any processor.

The Rabbit can be cold booted so unprogrammed flash memory

can be soldered in place.

You can write serious software, be it 1,000 or 50,000 lines of C

code. The tools are there and they are low in cost.

If you know the Z80 or Z180, you know most of the Rabbit.

A simple 10-pin programming interface replaces in-circuit

emulators and PROM programmers.

The battery backable time/date clock is included.

The standard Rabbit chip is made to industrial temperature and

voltage specifications.

CHAPTER 6

DYNAMIC – C

6.1 INTRODUCTION TO DYNAMIC C

Dynamic C is an integrated development system for writing embedded

software. It is designed for use with Z-World controllers and other

controllers based on the Rabbit microprocessor. The Rabbit 2000 and the

Rabbit 3000 are high-performance 8-bit microprocessors that can handle C

language applications of approximately 50,000 C+ statements or 1 MB.

6.2 THE NATURE OF DYNAMIC C

Dynamic C integrates the following development functions:

Editing

Compiling

Linking

Loading

Debugging

into one program. In fact, compiling, linking and loading are one function.

Dynamic C has an easy-to-use built-in text editor. Programs can be

executed and debugged interactively at the source-code or machine-code

level. Pull-down menus and keyboard shortcuts for most commands make

Dynamic C easy to use.

Dynamic C also supports assembly language programming. It is not

necessary to leave C or the development system to write assembly

language code. C and assembly language may be mixed together.

Debugging under Dynamic C includes the ability to use printf

commands, watch expressions, breakpoints and other advanced debugging

features. Watch expressions can be used to compute C expressions

involving the target's program variables or functions. Watch expressions

can be evaluated while stopped at a breakpoint or while the target is

running its program.

Dynamic C provides extensions to the C language (such as shared and

protected variables, costatements and cofunctions) that support real-world

embedded system development. Dynamic C supports cooperative and

preemptive multi-tasking.

Dynamic C comes with many function libraries, all in source code. These

libraries support real-time programming, machine level I/O, and provide

standard string and math functions.

Speed

Dynamic C compiles directly to memory. Functions and libraries are

compiled and linked and downloaded on-the-fly. On a fast PC, Dynamic C

might load 30,000 bytes of code in 5 seconds at a baud rate of 115,200

bps.

6.3 DYNAMIC C ENHANCEMENTS AND DIFFERENCES

Dynamic C differs from a traditional C programming system running on a

PC or under UNIX. The reason? To be better help customers write the

most reliable embedded control software possible. It is not possible to use

standard C in an embedded environment without making adaptations.

Standard C makes many assumptions that do not apply to embedded

systems. For example, standard C implicitly assumes that an operating

system is present and that a program starts with a clean slate, whereas

embedded systems may have battery-backed memory and may retain data

through power cycles. Z-World has extended the C language in a number

of areas.

DYNAMIC C ENHANCEMENTS

Many enhancements have been added to Dynamic C. Some of these are

listed below.

Function chaining, a concept unique to Dynamic C, allows special

segments of code to be embedded within one or more functions.

When a named function chain executes, all the segments belonging

to that chain execute. Function chains allow software to perform

initialization, data recovery, or other kinds of tasks on request.

Costatements allow concurrent parallel processes to be simulated

in a single program.

Cofunctions allow cooperative processes to be simulated in a

single program.

Slice statements allow preemptive processes in a single program.

The interrupt keyword in Dynamic C allows the programmer to

write interrupt service routines in C.

Dynamic C supports embedded assembly code and stand-alone

assembly code.

Dynamic C has shared and protected keywords that help protect

data shared between different contexts or stored in battery-backed

memory.

Dynamic C has a set of features that allow the programmer to

make fullest use of extended memory. Dynamic C supports the 1

MB address space of the microprocessor. The address space is

segmented by a memory management unit (MMU). Normally,

Dynamic C takes care of memory management, but there are

instances where the programmer will want to take control of it.

Dynamic C has keywords and directives to help put code and data

in the proper place. The keyword root selects root memory

(addresses within the 64 KB physical address space). The keyword

xmem selects extended memory, which means anywhere in the

1024 KB or 1 MB code space. root and xmem are semantically

meaningful in function prototypes and more efficient code is

generated when they are used. Their use must match between the

prototype and the function definition. The directive #memmap

allows further control.

DYNAMIC C DIFFERENCES

The main differences in Dynamic C are summarized here and discussed in

detail in chapters Language and Keywords.

If a variable is explicitly initialized in a declaration (e.g., int x

= 0;), it is stored in Flash Memory (EEPROM) and cannot be

changed by an assignment statement. Starting with Dynamic C 7.x

such declaration will generate a warning that may be suppressed

using the const keyword: const int x = 0; To initialize

static variables in Static RAM (SRAM) use #GLOBAL_INIT

sections. Note that other C compilers will automatically initialize

all static variables to zero that are not explicitly initialized before

entering the main function. Dynamic C programs do not do this

because in an embedded system you may wish to preserve the data

in battery-backed RAM on reset

The default storage class is static, not auto. This avoids

numerous bugs encountered in embedded systems due to the use of

auto variables. Starting with Dynamic C 7.x, the default class can

changed to auto by the compiler directive #class auto.

The numerous include files found in typical C programs are not

used because Dynamic C has a library system that automatically

provides function prototypes and similar header information to the

compiler before the user's program is compiled. This is done via

the #use directive. This is an important topic for users who are

writing their own libraries. Those users should refer to the

Modules section of the language chapter. It is important to note

that the #use directive is a replacement for the #include

directive, and the #include directive is not supported.

When declaring pointers to functions, arguments should not be

used in the declaration. Arguments may be used when calling

functions indirectly via pointer, but the compiler will not check the

argument list in the call for correctness.

Bit fields are not supported.

Separate compilation of different parts of the program is not

supported or needed.

There are minor differences involving extern and register

keywords.

6.4 FUNCTIONS USED IN DYNAMIC C

int DelayMs(long delayms);

Description:

Millisecond time mechanism for the co statement "wait for" constructs. The

initial call to this function starts the timing. The function returns zero and

6.4.1 DelayMs:

continues to return zero until the number of milliseconds specified has

passed.

Parameters :

delayms

The number of milliseconds to wait.

Return value

1: The specified number of milliseconds has elapsed.

0: The specified number of milliseconds has not elapsed.

Library:

COSTATE.LIB

6.4.2. DelaySec:

int DelaySec(long delaysec);

Description: Second time mechanism for the co statement "wait for"

constructs. The initial call to this function starts the timing. The function

returns zero and continues to return zero until the number of seconds

specified has passed.

Parameters:

delaysec

The number of seconds to wait.

Return value

1: The specified number of seconds has elapsed.

0: The specified number of seconds has not elapsed.

Library

COSTATE.LIB

6.4.3 log

float log(float x);

Description

Computes the logarithm, base e, of real float value x.

Parameters:

x Float value .

Return value

The function returns -INF and signals a domain error when x = 0.

Library

MATH.LIB

6.4.4 read_rtc:

unsigned long read_rtc(void);

Description : Reads seconds (32 bits) directly from the Real-time Clock

(RTC). Use with caution! In most cases use long variable SEC_TIMER,

which contains the same result, unless the RTC has been changed since the

start of the program.

If you are running the processor off the 32 kHz crystal and using a

Dynamic C version prior to 7.30, use read_rtc_32kHz() instead of

read_rtc(). Starting with DC 7.30, read_rtc_32kHz() is deprecated

because it is no longer necessary. Programmers should only use

read_rtc().

Return value

Time in seconds since January 1, 1980 (if RTC set correctly).

Library

RTCLOCK.LIB

6.4.5 COSTATE:

Indicates the beginning of a costatement.

Costate [ name [ state ] ]

{

……

}

Name can be absent. If name is present, state can be always on or init_on. If

state is absent, the co statement is initially off.

Void

To multitask using Dynamic C language extensions, most application

programs will have some flavor of this simple structure:

main()

{ inti;

while(1)

{

// endless loop for multitasking framework

costate

{

// task 1 . . .

//

body of costatement

}

costate

{

// task 2 ...

// body of costatement

}

}

}

6.4.6 CONTROL STATEMENTS

Wait for (expression);

The keyword wait for indicates a special wait for statement and not a

function call. The expression is computed each time wait for is executed. If

true (non-zero), execution proceeds to the next statement, otherwise a jump is

made to the closing brace of the co statement or co function, with the

statement pointer continuing to point to the wait for statement. Any valid C

function that returns a value can be used in a wait for statement.

Yield

The yield statement makes an unconditional exit from a co statement or a co

function. Execution continues at the statement following yield the next time

the co statement or co function is encountered.

abort

The abort statement causes the co statement or co function to terminate

execution. If a co statement is always on, the next time the program reaches

it, it will restart from the top. If the co statement is not always on, it becomes

inactive and will not execute again until turned on by some other software.

A co statement can have as many C statements, including abort, yield, and

wait for statements, as needed. Co statements can be nested.

Code Placement in Memory

Code runs just as quickly in extended memory as it does in root memory, but

calls to and returns from the functions in extended memory take a few extra

machine cycles. Code placement in memory can be changed by the keywords

xmem and root, depending on the type of code:

Pure Assembly Routines

Pure assembly functions may be placed in root memory or extended memory.

Prior to Dynamic C v 7.10 pure assembly routines had to be in root memory.

C Functions

C functions may be placed in root memory or extended memory. Access to

variables in C statements is not affected by the placement of the function.

Dynamic C will automatically place C functions in extended memory as root

memory fills. Short, frequently used functions may be declared with the root

keyword to force Dynamic C to load them in root memory.

Using SRAM

The flash file system can be used with battery-backed SRAM. Internally,

RAM is treated like a flash device, except that there is no write-cycle

limitation, and access is much faster. The file system will work without the

battery backup, but would, of course, lose all data when the power went off.

Currently, the maximum size file system supported in RAM is about 200k.

This limitation holds true even on boards with a 512k RAM chip. The

limitation involves the placement of BIOS control blocks in the upper part of

the lower 256k portion of RAM.

To obtain more RAM memory, xalloc () may be used. If xalloc () is called

first thing in the program, the same memory addresses will always be

returned. This can be used to store non-volatile data is so desired (if the

RAM is battery-backed), however, it is not possible to manage this area using

the file system.

When using FS1, since only one device type is allowed at a time, the entire

file system would have to be in SRAM. This is recommended for debugging

purposes only. Using FS2 increases flexibility, with its capacity to use

multiple device types simultaneously. Since RAM is usually a scarce resource,

it can be used together with flash memory devices to obtain the best balance

of speed, performance and capacity.

The basic program to calculate the slurry density.

#class auto

fontInfo fi8x10;

void main()

{

struct tm rtc;

auto float ip,a[500],sum,avg,Ep,Wp,num,denom,val,den,dw;

int i;

brdInit();

glInit();

dispInit();

glBackLight(1);

glXFontInit(&fi8x10,8,10,32,127,Font8x10);

digOutConfig(0xffff);

avg=0.0;

sum=0.0;

//empty=4.5003;

//water=3.504;

dw=1.0;

Ep=log(4.503);

Wp=log(3.504);

//den=num*dw/denom;

denom=Ep-Wp;

for(i=0;i<=499;i++)

{

a[i]=0;

}

while(1)

{

for(i=0;i<=499;i++)

{

a[i]=anaInVolts(8);

sum=sum+a[i];

}

avg=sum/500;

val=log(avg);

num=Ep-val;

den=num*dw/denom;

tm_rd(&rtc);

glPrintf(30,0,&fi8x10,"%02d:%02d:

%02d",rtc.tm_hour,rtc.tm_min,rtc.tm_sec);

glPrintf(0,13,&fi8x10,"I/P=%.4f",avg);

glPrintf(0,23,&fi8x10,"DEN=%.4fg/cc",den);

if(den<1.2)

{

ledOut(0,1);

ledOut(2,0);

ledOut(3,0);

ledOut(4,0);

ledOut(6,0);

digOut(8,0);

digOut(9,1);

}

if((den>=1.2)&&(den<=1.8))

{

ledOut(0,0);

ledOut(2,1);

ledOut(3,1);

ledOut(4,1);

ledOut(6,0);

digOut(8,0);

digOut(9,0);

}

if(den>1.8)

{

ledOut(0,0);

ledOut(2,0);

ledOut(3,0);

ledOut(4,0);

ledOut(6,1);

digOut(8,1);

digOut(9,0);

}

avg=0.0;

sum=0.0;

num=0.0;

val=0.0;

den=0.0;

}

}

OUT PUT:

The output of the above program will be displayed on the LCD keypad. The

varying density of the slurry is continuously displayed on the screen for the

corresponding change in voltage.

CHAPTER 8

CONTRIBUTION

Participated in Developmental work of sub units i.e. EHT,

Pre-Amplifier, Power supply.

And also participated in the software development of BL

2100 Micro controller working on Rabbit 2000 Microprocessor.

Program is executed and density is measured between

1.5 to 1.9gm/cc and corresponding led is glowing.

CHAPTER 9

FUTURE SCOPE

A database can be developed from the data available through serial port

communication.

The database stores the values of density at any given instant of time .

This database can be used to generate graphs on weekly, monthly or

yearly basis.

CHAPTER 10

CONCLUSION

The hardware of “Radiometric Density Gauge” is studied and the

software is generated using Dynamic C.

The programs for calculation of density and transmission of data on serial

port are generated. The testing is performed using the BL2100 micro controller to check

the reliability of the program.

It is concluded thus, that the program is reliable and accurate. It can be

used in real time applications.

CHAPTER 11

REFERENCES

Dynamic C user's manual.

BL2100 user's manual.

Rabbit 2000 user’s manual.

Let Us C Yashwant kanethkar.

Documentation of Radiometry

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Transcript of Documentation of Radiometry