Usbpicprog is an USB in circuit programmer for Microchip PIC processors family PIC10F, PIC12F, PIC16F, PIC18F, PIC24F, PIC32F and I2C Eeprom 24xx. The hardware is as simple as possible, the current version only contains one PIC18F2550, 4 mosfets, and besides the connectors a hand full of passive components.
Usbpicprog consists of three main components:
- Hardware – A PCB design which contains the necessary components to interface from the USB port to a Microchip ICSP (in circuit serial programming) header.
- Firmware– The software that runs on the processor on the PCB. It contains the USB framework, and high and low level functions for PIC in circuit programming.The firmware can also be divided into two parts:
- The bootloader (Microchip Picdem bootloader) has to be loaded only once, after that this part of the firmware can be upgraded through the usbpicprog interface.
- The usbpicprog part of the firmware contains the actual programming algorithms for all the implemented PIC devices.
- PC software – A wxWidgets based (cross platform) application to communicate with the usbpicprog hardware / firmware. This application is known to function well on Linux, Windows (XP or later) and Macosx.
Schematic – usb pic programmer – Usbpicprog
The hardware is built around a microchip PIC18F2550, this microcontroller has on board USB capabilities. The schematic and PCB have been designed in Kicad, an open source EDA solution
The PCB files are available in Gerber format and the schematic in pdf in the download section so that you can open them with your favourite tool.
The code for the PIC18F2550 has been written using Microchip C18. It was based on the PicDem USB stack from Microchip. The data is sent in blocks through interrupt read /write and the programming functions are implemented in firmware.