Last time I went through the design of my new standalone anemometer. Now it’s time to build this thing and see if it works as planned.
After I fried a couple of chips on my driver circuit testing board due to a wrong chip in the power supply I was a bit more careful this time and built up the board step by step.
Only after I confirmed that the power supply was ok I dared to solder some more.
The next step was to add the PIC32 with the crystal, the programming header and all the caps they need. This is a chip family that I’ve never used before so I wanted to first see if I can program it. All went well and I managed to get it to run on the crystal’s 8MHz boosted up to 40MHz by an internal PLL. So I was ready for the rest.
I wrote some very basic software and confirmed that at least the basics were working ok. I was able to send and receive pulses, the pulses got amplified, the zero-crossing detector worked and so forth.
As mentioned, I’m entirely new to the PIC32 microcontroller series. There are a lot of similarities to the PIC16 and PIC18 series that I’m quite familiar with but still it’s always a challenge to work with a new family of chips and the tools that come with it. I took me the better part of an afternoon to master the vectored interrupts with the different priority levels and so on.
By the way, with this project I’m using the free MPLAB X IDE with the also free XC32 C compiler from Microchip. So anyone is able to write, modify or compile code for this thing with free software. At least at the moment you need a programmer to actually burn the chip. But the PICkit3 only costs around 50 dollars and my idea is to write a USB bootloader so that any user can modify the software of a pre-programmed board.
So now comes what I think might be the hardest part: Getting the USB to work. I’ve spent quite a few hours so far but haven’t managed to get it working properly yet. If anyone has experience with this kind of software development – Let me know, any help is highly appreciated.
It now works: Click here to view it.