What is Arduino? Arduino is a ATMEL 168 micro-controller kit designed specially for

small projects User friendly IDE(Integrated Development Environment) USB connection with serial communication Open source programs available Built in ADC Easy to use platform with most of the functions provided on board

Introduction to Arduino

ATMEL 168

RESET SWITCH

POWER PORT

ADC PINS

ON BOARD CRYSTAL

8 BIT DIGITAL PORT WITH COMMUNICATION PINS

8 BIT DIGITAL PORT WITH PWM PINS

USB CONNECTOR FOR COMPUTER INTERFACING

EXTERNAL SUPPLY – 6V DC

Why Arduino? Arduino has multiple inbuilt features and acts as a combination

of 10 bit analog to digital converter(ADC), storage and microprocessor.

Arduino comes up with its own software for analyzing, processing and calculation of unknown parameters.

It provides a facility to write programs, compile them and program the microcontroller all by itself.

It can take 6 analog inputs and a time and process all of them without any difficulty.

There are 2 digital 8 pin ports available and they can be used for interfacing with LCD, LEDs, to drive an other circuit and so on.

Sample programs• ADC – Analog to Digital

Converter

Takes analogue input from Potentiometer

Converts 0-5V analog signal to 0-1023 Digital values

Displays it on screen using serial communication

Displays it on 16x 8 LCD

Analog to Digital Converter• CODE :• void setup() {• Serial.begin(9600); //begin serial communication with

computer• }• //void loop runs continuously on µc • void loop() {• int sensorValue = analogRead(A0); //reads analogue pin A0• Serial.println(sensorValue, DEC); //prints it on serial monitor• }

LCD Interfacing

LCD Interfacing• CODE:• LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

• void setup() {• lcd.begin(16, 2); // set up the LCD's number of columns and rows: • lcd.print("hello, world!"); // Print a message to the LCD.• }

• void loop() {• // set the cursor to column 0, line 1• // (note: line 1 is the second row, since counting begins with 0):• lcd.setCursor(0, 1);• lcd.print(millis()/1000); // print the number of seconds since reset:• }

LCD Output

Hardware is reduced Microprocessor

Brain of the system

ADC10 bit built in

Storage4kb memory connected

Input – Output ports

ARDUINO KIT

Analog signal

16 x 8LCD

display

Usb port of

computer

Frequency calculation for square wave

Firstly, a square wave is generated using a 555(timer circuit).

The values of R,C are adjusted such that the frequency of output is close to 60Hz.

This square wave signal is given to one of the analog pins of Arduino.

Code for the frequency calculation is written, verified and programmed using the Arduino software.

The calculated frequency is displayed in the serial monitor of the software or using an LCD.

Frequency calculation for square wave

ARDUINO KIT

SERIAL MONITOR

LCD

Measurement of live Power System Frequency

Taking samples from actual 230V AC Supply

The Problem

POWER SUPPLY

230 V AC SIGNAL

ARDUINO KIT

0-5 V DC SIGNAL

TRANSFORMER - 2.5 TO 2.5 V

&DC OFFSET OF 2.5 V DC

Live frequency estimation by Arduino

The live power signal of 230V magnitude is stepped down by a transformer to 3V.

This AC signal of 3V is then fed to one of the analog pins of Arduino.

Arduino microcontroller is able to read the input only during its positive half cycle.

A set of 250 samples of this sinusoidal wave is taken by the kit which has a sampling time interval of .112ms.

As per the traditional zero cross-over method, the frequency of the live signal is calculated.

Live frequency estimation by Arduino 230V/3V Transformer

ARDUINO KIT

SERIAL MONITOR LCD

Live AC signal

Taking all samples of the live signal Since , the Arduino cannot be fed with an AC signal of high

magnitude, the signal is first brought to an AC wave of 6V magnitude using a step down transformer.

This wave is given to the inverting pin of 741 Op-Amp IC using a variable resistor such that the output due to this signal alone is 2V.

A dc voltage is fed to the non inverting pin of 741 so that the output due to this signal alone is 3V.

This sinusoidal non AC signal varies from 0V to 5V. This signal is finally given to one of the analog pins of the Arduino. Analog-serial-input code is programmed into Arduino and samples

of the signal can be seen in the serial monitor every 1 ms.•

Taking all samples of the live signal ARDUINO

KIT

Serial Monitor

Limitations of ArduinoCalculations of very high frequency signals is not possible

using Arduino as the sampling rate of ADC is low.

The input signal must be non AC and must posses a magnitude of less than 5V.

Heavy mathematical functions like inverse trigonometry, modulus

• operation, complex equations cannot be performed by the Arduino software.

•Thank you