I bought this programmer from local supplier a few years ago. This is a GTP-USB-lite programmer clone and beautifully build as sandwich style.
Some drawbacks of this programmer are:
- I noticed that this programmer don’t work with some PC/Laptop USB port for unknown reason.
- Don’t support Windows 7
- Not opensource,
Anyway, GTP-USB programmers are the best and DIY friendly at their age. Mostly, I used PicKit2, PICKit3 as main programmer. So, I leave this programmer in a corner of my desk for a while. Last week, I noticed a post in DP forum about hacking aka flashing this programmer.
The original blog post here.
At the last weekend, I try to flash my GTP-USB-Lite programmer with new firmware and to use new software. The procedure is very simple.
- GTP-USB-Lite and USBPICProg are very identical hardwares, USB interface, PIC18F2550, the same charge pump, same programming header’s pin.
- The difference are;
- GTB-USB lite used 8MHz crystal and USBPICProg uses 12 MHz crystal
- LEDs are connected at PIC pins 11,12 and 13 in USBPICProg and pins 27,28 at GTP-USB-Lite.
USBPICProg hardware , firmware, PC software (The best thing is all are opensource :D)
- First, to take off and flash programmer’s PIC18F2550 with boot loader and to change 12MHz crystal in circuit
- Download and installed PC software and install it.
- Download last firmware and attached programmer. The PC will detect bootloader and install bootloader USB interface driver. Launch the PC programmer software and bootloader is activated and update firmware.
- USBPICProg-0.6.0-software –> Updated Firmware
- Then, remove programmer from USB port. Connect PGC pin (RB6 , Pin No 27 of PIC18F2550) to ground to de-activated the bootloader and activated USBPICProg programmer mode. The PC USB port will detect and installed new device (USBPICProg) driver.
Before final launch, I simply cut the trace between LEDs and RB7,RB6 (pin 27,28) and connected LED’s resistors to Pin 11,12. LED shows signal now.
For now, I can use reborn USBPICProg as a backup programmer. I renamed it USBPICProg because it is no more GTP-USB Lite.