Web platform: Firmware upgrades
We ported the open source ds30 Loader bootloader to the web platform so it can be programmed through the USB connection; no PIC programmer required. The ds30 Loader project has serial bootloader firmware for most PICs, and bootloader software for most computer operating systems. The bootloader is programmed into the chip once (at the factory) with a PIC programmer like an ICD or PICKIT, then future updates can be done over the USB port.
The bootloader resides in the uppermost page of the PIC program memory. It activates immediately after power on, then waits for commands from a PC connected to the FTDI USB->serial converter.
The bootloader passes control to the main firmware if it doesn’t detect an update request after three seconds.
- Power up the web platform.
- Attach a USB cable from a computer to the web platform.
- Start the bootloader client software.
- Configure the bootloader to communicate with a PIC 33FJ128GP204 at 115200bps on the appropriate serial port for your system. See the image above.
- Press the reset button on the web platform. Next, click download on the bootloader software within 3.5seconds. Always follow this order or the bootloader may be damaged. The new firmware will be loaded into the PIC.
- The bootloader will automatically pass control to the main program when the upload completes.
If the client warns you that the bootloader will be overwritten, ALWAYS CANCEL.
The compiled firmware end address is 0×153fe. The bootloader resides in the page starting at 0×15400, and the client will refuse to upload new firmware that overwrites the bootloader.
If warning is ignored, the bootloader will be overwritten. Program the bootloader again using a PIC programmer.