My PIC 24 evaluation board
This is a selfmade evaluation board for PIC24FJ microcontrollers. I wanted to use this microcontroller as a storage driver for other FPGA projects, but did not know the PIC24 family at all. I knew that this chip can handle USB devices and has embedded host functionality, but never tried myself. My first thought was that I buy a complete devboard from Microchip, but later I decided to design this hardware. For sure it was not cheaper than a factory produced card, but at least I have learned the basics of the PIC24 implementations. The main chip is a PIC24FJ256GB microcontroller, 80 pins.
The card itself has those functions I wanted to test, such
- USB host connector for pendrives and other HID devices
- RS232 line for general communication with PC (using MAX3232 for level shifting)
- four LEDs to have visual feedback
- a 4Mbits Serial FLASH.
- a GPIO port with several free PIC line for future development
- 16MHz oscillator for good clock source, because the USB module needs very accurate timing
After fixing my wrong soldering, the board started to work all the way I expected. Obviously I had to make the software environment working, too. I use the MPLAB IDE and the XC16 compiler. One can download them for free from Microchip’s website.
I could program it with my PICKIT-2 programmer and slowly tested all the features. Based on the documentation and the example applications provided by Microchip, now I can handle pendrives, communicate with PC via the RS232 line, and reading/ writing the SPI flash. Also I can blink the leds :-)
Well, it is not a perfect design though. Because I did not know the microcontroller at all, some features can not be tested with this board. For example, the PMP paralell module lines are not wired to the GPIO pins. My fault. But I am happy with this board anyway. I can test functions, try example apps, and learn about the PIC.
Some references
PIC’s datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/39897c.pdf
joco