Sunday 10 February 2013

Raspberry Pi and Leds strip RGB

This project came up with my friend who wanted cover his room with leds strip and control all of them with a simple http request.
The idea was to be able to change color and the brightness, so I had to buy just a few components to make the controller:

  • 4x MOSFET N-Channel STP75NF75
  • 1x Breakout Adafruit
  • 1x 16 Channels servo Adafruit
  • 1x PCB
  • some wires

I just placed all my components on a PCB board, connected the 16 channels servo via I2C and each MOSFET to the leds strip.

Why MOSFET and 16 Channels?
Someone is maybe asking why I am doing this total mess with MOSFET.
The answer is that the 16 Channels couldn't give me the same result that I was expected. This means I couldn't pass the max power through this board, so I avoided the problem by using  4 MOSFET that are getting the main source power, 12V, and Raspberry is sending the right pulse to each ones.

HTTP Request
My friend made a little script in Python that is waiting for a POST request with Red, Green, Blu, Power as parameters and then it will send the new color through the 16 Channels.

I don't really have so much code, I took the example from Adafruit to drive the 16 channels ( 3 lines ) and then parsed the 4 parameters to send the value between 0 and 4095.
Obviously I can post something if someones needs a little guide how to parse these values =).