I want an AVR ISP programmer that uses the systems power on vcc and the gpio. It should use proper levelshifters (4 of them - SN74LVC1T45) giving a range of 1,65 <=> 5,5 on system side and whatever brain I choose for my progger. Can be especially interesting for boards with "exotic" chips and power levels.
solder jumper for slow programming
switch to power devices with 5V if needed
edge connector for pogo pins or socket
the rest is basically a copy of the standard USBASP devices
I wanted to take a look at the firmware of my #BINCL - binary coded decimal 10mm LED clock to get rid of the pcbs I still have from the first batch. I quickly ran into the problem of having only 5V usbasp modules or my version one board with pogo pins, able to talk to 3v3 devices, but not power them. In this revision I've added a AP2112K and a second switch, changed the usb plug and made it a single side pcb. The edge connector is inverted from before and will now hold an ISP6 port instead of the pogo pins!
Boards aren't routed yet, price in a size like this on OSHpark for 3 boards is
Overall I'm pretty happy with it, but I'm a bit sad that I can't use this with boards where pinheaders are already present. Would have been nice to have a standard 2x3 ISP socket on it and change between cables, pogopins and avr clamps. When it comes to power, a little regulator for 3V3 would be nice too. Basically switch between 5V, 3V3 and selfpowered.