USBTinyISP Problems.. Works 1 out of 20 times...

[Dr. Bogger]

Hello,

I received the new kit today, soldered it together, and it works perfect!
There must have been something wrong with the old one, I'm going to guess either bad attiny chip, or the shift register is bad...

[argon99]

I have read all the posts for this thread. What caught my eye is the OP said that he checked for bridging of the solder joints visually and with a DMM. I doubt that it is a bridge, or it wouldn't work at all, but a cold joint sounds like it could cause the problems he is having. It's obviously an intermittent problem. Cold joints present as intermittent problems. If this was me I would go over every solder joint with a hot iron. It couldn't hurt and might just fix it.

[Rodot]

Hello,
I had the same problem, and I think it was because I was powering my project through the USBtinyISP. When I unplug everything from my project (the tft screen, the accelerometer... it's a kind of gameboy) it works fine. It's probably because I was above the 100mA limit from the programmer. Just in case someone has the same problem.