programming basics of arduino

1. Programming
of
Arduino

2.  Arduino programs can be divided in three
main parts:
 STRUCTURE
 VALUES -VARIABLES
-CONSTANTS
 FUNCTIONS

3. STRUCTURE
 The basic structure of the arduino programming language is fairly
simple and runs in atleast two parts.
 These two required parts,or functions, enclose blocks of statement.

4. Setup()
Setup() function is called when a sketch starts
Use to initialize variables , pin modes , start using
libraries etc…
It will only run once,after each powerup or reset.
So generally it is used to prepare your ardruino serial
communication and pinmode().
It must be included in program even if no lines are there.

5. Example
int buttonPin = 3;
void setup()
{
Serial.begin(9600);
pinMode(buttonPin, INPUT);
}
void loop()
{
// ...
}

6. Loop()
After calling the setup() function, the loop() function does
precisely what its name suggests, loops consecutively
 i.e it allows us to execute a statement or group of
statements multiple times.
Allows program to change, respond and control the Arduino
board.

7. Example
void loop()
{
digitalWrite( pin ,HIGH ); //turns ‘pin’ on
delay(1000); //pause for one second
digitalWrite( pin ,LOW ); //turns ‘pin’ off
delay(1000); //pause for one second
}

8. Variables
 A variable is a way of naming and storing a numerical value for later use.
 It can be continuously changed as opposed to constants whose value never changes.
 Data types says the size of variable.
 Eg: int a,b;
 The above statement declares a variable ‘a’ whose size can be of 16 bits.
 Initializations can be done while declaring or in further part of program.
 Eg: a=20; b=10 //initializing variable
a=b; //changing variable value
 You can use same variable name in same program but it depends
on scope of variable.

9. Functions
 A function is a block of code that has a name and a block of statements
that are executed when the function is called.
 Custom functions can be written to perform repetitive tasks and to
reduce clutter in program.
 Functions are declared by first declaring the function type.
 Function type tells the type of value to be written by the function.
 Eg: int a() //for integer type to be returned
 If no values is to be returned the function type would be void.
 After name of function name we pass can parameters of function in
parenthesis.

10. Example
int delayVal()
{
int v; //create temporary variable ‘v’
v = analogRead(pot); //read potentiometer value
v /= 4; //converts 0-1024 to 0-255
return v; //return final value
}

11. Basic Functions Of Arduino
Digital I/O
pinMode()
digitalWrite()
digitalRead()
Analog I/O
analogReference()
analogRead()
analogWrite() - PWM
Time
millis()
micros()
delay()
delayMicroseconds()

12. LED BLINK
Description:
In this lesson we will,
1. Build and wire a device with one LED, resistor, and
Arduino board.
2. Program the device to “Blink the Light”
3. Identify the flow of electricity / signal in this computing unit.
4. Use the Blockly Programming system to control speed of
Blink.

13.  You will need:
 1. LED Light Bulb (Any Colour)
 2. 330 Ohm Resistor
 3. Red Wire
 4. White Wire
 5. Black (Or dark colored Wire)

14. Process:
1. Run a red Wire from the 5V Pin to the Red Rail on the
Breadboard. This will connect the current side of the
circuit.
 2. Run a black (or dark coloured wire) from the Gnd Pin of
the Arduino to the Blue Rail on the far side of the
Breadboard.

16.  3. Plug an LED bulb into the circuit. Note that the longer pin will face the
Arduino Board and the pins should cross the “gap” in the breadboard.
 4. This step is VERY IMPORTANT!!! Plug a 330 OHM resistor from Port B5
to Ground (The blue rail).
 An LED bulb must ALWAYS have a Resistor in the circuit. If we do not use a
Resistor, we will burn out the bulb or the Arduino

17. 5. Now we will run the signal wire. Wire Pin 13 on the
Arduino to the Breadboard. This will carry the current from
the Arduino Pin to the LED and allow the Arduino to switch
on and off the LED.

18. Sketch Programming:
1. Start your Arduino Sketch Program by clicking on
the Sketch Icon.
2. Save the code by selecting “File-Save” and
naming the program “lastnameBlink”.