Osman GÜLERCAN16169230356

Graduation Project:

RF TELEMETRY APPLICATION

Telemetry

• allows remote measurement and reporting of information.

• refers to wireless data transfer mechanisms(e.g. using radio or infrared systems)• telephone or computer network, optical link

or other wired communications.

Applications

• 1- Motor racing- to properly tune the car for optimum performance.- accelerations (G forces) in 3 axis, temperature readings, wheel speed, and the displacement of the suspension- the driver inputs are also recorded so that the team can assess driver performance

Applications

• 2-Defense, space and resource exploration systems- NASA and ESA use telemetry/telecommand systems to collect data from operating spacecraft and satellites.- Engineers need critical system parameters to analyze (and improve) the performance of the system.

Applications

• 3- Medicine- used for patients (biotelemetry) who are at risk of abnormal heart activity.- patients are outfitted with measuring, recording and transmitting devices.- an alerting function can alert nurses if the patient is suffering from an acute or dangerous condition.

RF TELEMETRY APPLICATION

RF TELEMETRY APPLICATION

• MCU : Microchip PIC16F877A

• RF Moduls : UDEA’s ATX34S (transmitter)

UDEA’s NRX-34U (receiver)

• Sensor : LM 35 : °C Temperature Sensor

• LCD Module : 16x1 Line HD44780-Based

Microchip PIC16F877A• 256 bytes of EEPROM data memory

• 2 capture/compare/PWM functions

• 8 channels of 10-bit Analog-to-Digital (A/D) converter

• 2-wire Inter-Integrated Circuit (I²C™)

• Universal Asynchronous

Receiver Transmitter(USART)

Analog-to-Digital (A/D) converter

• The conversion of an analog input signal results in a corresponding 10-bit digital number.

• The A/D module has four registers. These registers are:- A/D Result High Register (ADRESH)- A/D Result Low Register (ADRESL)- A/D Control Register 0 (ADCON0)- A/D Control Register 1 (ADCON1)

ADCON0 / ADCON1

RF ModulsATX-34S : data transmitter NRX-34U-R : data receiver

General Feautures:• 433.920 MHz. UHF band• High Frequency Stability• Low power consumesApplication Areas:• Remote Control Systems• Security Based Alarm Systems• RF-Telemetry Systems

Data Communication via RF Modules

• Physical CharacterCommunication Type: AsynchronousCommunication Speed: 2.4 KbpsLink: RS232-TTL (0-5V DC)

• Format of Data8 bit data bits, no parity bit and one stop bit

• Communication ProtocolATX-34S transmitter module has a digital data input (DIN) which is given data by user to send via RF.The standard data protocol is

TX : preamble + synchron+ data1+.....+dataX

Data Format

• TX: preamble + synchron+ data1+.....+dataX• Preamble: provides hardware

synchronization.- Usually 5 byte 0x55 or 0xAA.

• Synchron: helps software synchronization- can be 5 byte 0x00 + 5 byte 0xFF.

ASK-on-off keying (n=2)(transmit morse code)

-four-level encoding (n=4)

RF Moduls

• UDEA’s ATX34S (transmitter)

Pin No Pin Name I/O Description

4 Ant O 50 ohm

antenna

connection

point

3 Gnd -

2 DIN I Digital Input

1 Vcc - +5V

RF Moduls

• UDEA’s NRX-34U-R (receiver)

Pin No Pin Name I/O Description

1 Ant I 50 ohm

antenna

connection

point

2 Gnd - Ground

3 Vcc - +5V

4 RSSI O Analog

Output

5 Dout O Digital Output

RSSI OUT• DOUT always has noise• RSSI output is used to detect RF signal

RF Modul can be used between -117 dBm ~ -55 dBm

Simple Codes For Transmitter

• if(button==0• {

• send(0x55); // 5 byte 0x55 (preamble) • send(0x55); • send(0x55); • send(0x55); • send(0x55); • • send(0x00); // 5 byte 0x00 ve 5 byte 0xff (synchron) • send(0x00); • send(0x00); • send(0x00); • send(0x00); • • send(0xff); // 5 byte 0x00 ve 5 byte 0xff (synchron) • send(0xff); • send(0xff); • send(0xff); • send(0xff); •

• DI=0; // stop biti • DI=1; // start biti • p_width(); • • send(0x42); // send data • • DelayMs(250); // 500 ms delay• DelayMs(250); }

Simple Codes for Receiver

void fivebyte0() { for(;;) { if(Dout==0) //senkron 5 byte 0x00 { for(;;) { DelayUs(1); plus0++; if(plus0>=600) { while(Dout==0); fivebyte1(); // goto fivebyte1(); return; } if(Dout==1) // 5 byte 0x00 couldn’t detect break; } plus0=0; } } }

LM 35: PRECISION °C TEMPERATURE SENSOR

• - Calibrated directly in ° Celsius (Centigrade)• - Linear a 10.0mV/°C scale factor• - 0.5°C accuracy guaranteeable (at a 25°C)• - Rated for full -55° to +150°C range• - Suitable for remote applications• - Low cost due to wafer-level trimming• - Operates from 4 to 30 volts• - Less than 60 mA current drain• - Low impedance output, 0.1 Ω for 1 mA load

L7800 SERIES: POSITIVE VOLTAGE REGULATORS

• provide local on-card regulation• eliminate the distribution problems • can deliver over 1A output current.

HD44780-Based LCD Modules

- The HD44780 has two 8 bit registers:

an instruction register (IR) & a data register (DR)

- Character Generator ROM (CG ROM)

- Character Generator RAM (CG RAM)

instruction register(IR) vs data register(DR)

• The IR stores instruction codes such as display clear and cursor shift, and address information for display data RAM (DD RAM) and character generator RAM (CG RAM). The IR can be written from the MPU but not read by the MPU.

• The DR temporarily stores data to be written into the DD RAM or the CG RAM and data to be read out from the DD RAM or the CG RAM.

16x1 Line HD44780-Based LCD ModulesPIN NUMBER SYMBOL FUNCTION

1 Vss GND

2 Vdd + 5V

3 Vo Contrast Adjustment

4 RS H/L Register Select

Signal

5 R/W’ H/L Read/Write Signal

6 E H → L Enable Signal

7 DB0 H/L Data Bus Line

8 DB1 H/L Data Bus Line

9 DB2 H/L Data Bus Line

10 DB3 H/L Data Bus Line

11 DB4 H/L Data Bus Line

12 DB5 H/L Data Bus Line

13 DB6 H/L Data Bus Line

14 DB7 H/L Data Bus Line

15 A/Vee + 4.2V for LED (RA =

0)

16 K Power Supply for B/L

(0V)

Thank You

RF TELEMETRY APPLICATION