• Move from AVR to PIC

    AndrewMcDan • 03/18/2015 at 23:28 • 0 comments

    As I was rummaging through a parts bin, I came across a board that I bought quite a long time ago: a chipKIT Max32 board made by Digilent. In case you haven't heard of it, it's an Arduino compatible board that comes in several flavors, including Uno form-factor (Uno32) and Mega form-factor (Max32). The boards are based on 32-bit PIC processors that are incredibly powerful. I have two of the Max32 boards and, after a little research, I found that they are capable of PWM on every digital output through software.

    Having the ability to setup a lot PWM give me the option to add quite a lot of fan control channels and RGB channels. Not to mention, the board has three more hardware serial ports than the Uno I originally planned on using, allowing me to interface my fan controller with just about anything. And at this point, I'm thinking the anything will probably start off with an ESP8266, because, reasons. Maybe I'll add in an interface to my home automation project with it.

    Another advantage to using the Max32 in place of a standard Arduino is that the Uno outputs PWM at a preset 1kHz and the Max32 allows the program to set the frequency. At 1kHz, the fans make an incredibly annoying whine that I could only get rid of by adding capacitors to the design. With the Max32, I can set the frequency to about 22kHz and the whine goes away.

    I have completed most of the assembly of the MOSFET boards and began testing various structures for the program. I'll take some pictures and add a GitHub page this weekend.