This is an old post, preserved for reference.
The products and services mentioned within are no longer available.
After using the ATMega328 from my Arduino UNO in the
ZX81 USB Keyboard, I needed to replace it. The chips themselves are only £3-4, so is much cheaper than buying a whole new Arduino. The only issue is the chip needs to have the bootloader burned into it before it can use the USB Serial programming in the Arduino. You can actually by them with the bootloader already programmed for about £5, but I was looking to burn it myself to give me more options in the future.
This needs to be programmed using the standard 6 pin AVR ISP header. I was planning to get a programmer at some point in the future, but I though I might try to see if I could knock one up quickly. I found a few designs online for parallel port, but the one I tried didn't work, probably due to the length of the cables, or the drive capabilities of the parallel port. I had the same problems back in the early days of PIC work before I got a PIC Start.
So I had a look around at other options and found the USBtiny ISP from adafruit, as a kit from
.:oomlout:. in the UK, so this is just a quick review of that.
It arrived as kit this morning, it would have been nice to have a single sheet schematic or something, but the
step by step build instructions are online,
It didn't take long to build up the board, clip it into the case and away it went. and worked first time.
It's nice to find things that just work without having to hack about with anything!
