Step 3: Heatsink, Enclosure, Cooler
Of course I tested the setup on a prototyping breadboard before soldering everything together and made some tests. I wanted to know if the chip can take full white light on all 15 channels for a longer time. So I illuminated my room with 5 LED strips fully on for a few minutes and measured the temperature with my IR-thermometer and with one of my best tools, my hands. It was a little bit hot but didn't get any hotter after one minute or so.
I decided to add a heatsink to the unit. Because I didn't have any dedicated heatsink for such chips, I just cut one of my old broken XBOX 360 heatsinks into two pieces. After that it was still a little bit oversized, but ok. I added some heat transfer paste to the chip and screw the heatsink tightly on top. Do not forget the paste if you want to use a heatsink, because if you do so, the solution is useless.
Because all of the devices are sensitive I put all of them into an enclosure and fixed them with hot glue. Because the enclosure was too tight for the big heatsink I removed it.
Instead of the heatsink I wanted to add something else because inside of the closed plastic casing everything would get even hotter. I had a small 12V cooler laying around at home and connected it to 12V directly. The fan was way too fast and too loud to be on all the time I use my system. So I connected it to 3.3V of the arduino and that works very good. It is really quiet and after I added some holes to the case the air can flow through it.