Friday, 16 October 2015

Led blinking with Arduino Uno

Let's start with led blinking in arduino

Led Blinking Code
Schematics using Fritzing
You can download the source code from the following link:

The code is self explanatory. Pin number 13 of arduino is configured as output. cost int led=13
makes it a read only variable and also pin number 13 is named as led.
You can use any digital pins i.e from 0 to 13. We have taken pin number 13 because the in-built led of arduino is connected to pin number 13. If you are going to use any other pin please don't forget to connect the external resistor having a minimum value of 220 ohm resistance.

delay(1000)   // It provides a delay of 1000 ms i.e. 1s

Now coming to the calculation of resistance, it is as per according to Ohm's law:


The led have forward current of  about 25 milli Amps and voltaage provided by arduino is +5 volts
I = V/R  ....... I  = 5000/25, which comes out to 200 ohms. But this is not a standard value and the nearby value is 220E. Feel free to comment here.