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USBTinyISP Problems.. Works 1 out of 20 times...
Moderators: adafruit_support_bill, adafruit

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

by Dr. Bogger on Thu Mar 22, 2012 7:12 pm


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...
Dr. Bogger
Posts: 9
Joined: Sun Nov 06, 2011 6:27 pm

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

by argon99 on Thu Mar 22, 2012 9:24 pm

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.
Posts: 2
Joined: Sun Aug 07, 2011 2:53 am

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

by Rodot on Sat Aug 11, 2012 6:23 am

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.
Posts: 1
Joined: Sat Aug 11, 2012 6:16 am

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

by bitwise1001 on Fri Jul 25, 2014 10:32 pm

I have a similar problem. My USBtinyISP used to work perfectly. now I've started to get nothing but mismatch verification errors. I've tried both the power jumper on the usbtinyisp and separate power supplies, etc to no avail. reading and writing fuse bits seems to work fine, but writing to flash doesn't pass verification. It's not the chips themselves (I ruined a perfectly good arduino uno trying to burn a new bootloader via the isp headers, and brand new chips don't work either). I also used to get partial programs to work, but not anymore. I can detect the correct atmega328p device signature, so it's hooked up properly, etc.

It just won't work beyond that.

UPDATE: I was able to repair my arduino uno boards using a leonardo as isp. I think I have a dead usbtinyisp.
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Joined: Fri Jul 25, 2014 10:06 pm