The main idea of this project is to make a small and low-cost version of a PIC microcotroller programmer. Mainly I've designed this programmer for PIC16F505. If successful, I will continue the support for other PIC devices.
I think that this programmer is useful for those, who would like to experiment with assembly language. PIC16F505 has only 33 instructions to learn, so I think this is the simplest MCU on the market for learning assembly.
There are a lot of low-cost PIC programmers, but unfortunately they use RS232. I wanted an USB version. An ideal solution was to use a PIC18F2550, but this MCU is too expensive. So the cheapest USB solution is to use an Attiny84 with V-USB library. The main disadvantage of this approach is the software. So to make it work, I have to combine V-USB library and original PICKIT software. And of course some PC drivers have to be written too.
P.S. Any critics, ideas or help are welcome.