I have finally (almost) finished my switching LED driver, and boy was it journey! It started with my first time working with the mains voltage here in Germany, and hopefully also the last time. After going through the trouble of rectification, getting the right voltage out of my transformer, filtering and regulating the output voltage, I am sure to use a finished SMPS in future! Afterwards I also made my first switching power supply, while also using inductors for the first time, at this point I was starting to regret my decision. Soon after I completed the Arduino on a breadboard (you guessed it, first time) and managed to bring all of it together. This is what my final product looks like after a few months of work between long school days:
I might release a schematic if this project makes it further (it's a lot of work to make one).
With the board ready it took merely an hour or two to refine the fast PWM and current control and upload the code. Sadly my program was attacked by a bug, and this is what my board looks like now:
My Uno is managing the serial IO, the Oscilliscope is monitoring the PWM and power source, the programmer is pushing new code constantly and my lab bench power supply is providing a clean power source, but I still can't for the life of me figure out why my Arduino is randomly crashing! So I guess it will be a little while until I can mount my electronics ;(
If you wan't to see the issue, I posted a question on stack exchange: http://arduino.stackexchange.com/questions/25414/arduino-crashing-and-rebooting