Programming the LED

Switching on an LED by a command is one thing. The other is controlling the LED programmatically. In this recipe, we are going to write a real program in C and in Python to switch the LED on and off periodically.

Getting ready

We require the very same breadboard construction from the previous recipe:

• A Linux system on the Banana Pi

• Access to the shell

• A 5 mm LED (forward voltage 2.0 V)

• A 470 Ω resistor

• A breadboard

• Two female to male jumper wires

Construct the circuit as we have seen previously.

How to do it…

Once we have the construction, we can proceed with the steps given in the following sections.

Programming the LED with C

We start by programming the LED in the classic C programming language.

1. Power on your Banana Pi.

2. Open a shell.

3. Create a source code directory and change location to it:

   $ mkdir ~/source
   $ cd ~/source
   

4. Create a source file using nano:

   $ nano led_test.c
   

5. The nano editor will open. Write the following code in C:

   #include <wiringPi.h>
   
   int main(void) {
           ...