Causes for flaky connections

USB AVR Programmer and SPI interface. Adafruit's USBtinyISP.

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antfriend
 
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Causes for flaky connections

Post by antfriend »

I'm using the USBtinyISP to program an ATmega8 on a Solarbotics ScoutWalker III robot.
The USBtiny500 glue runs fine but AVR Studio 4 won't connect.
AVRDude sometimes connects. I'm running it from the WinAVR install with the patches as per the USBtinyISP instructions.
With multiple attempts to connect I usually get "avrdude: initialization failed, rc=-1" but once in a while it will connect but report "invalid device signature" with varying device signatures on various attempts. And once it connected but reported that fuses had changed. Attempting to change them back failed.
Is this screwy behavior indicative of a bad chip, driver problems, connection problems, or any or all of those? I'm a newbie, thanks for any help! Building the USBtinyISP kit was pretty fun!

adafruit
 
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Post by adafruit »

do you have a screenshot of avrdude when it gets a bad signature?
try a lower bitrate (using -B) such as -B 20 in case its a slow chip
are you -sure- you have it wired up correctly?

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antfriend
 
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got it in Studio

Post by antfriend »

I got it working with AVR studio by trying different COM ports with com0com. I'll try the lower bitrate in avrdude after I bask for a while in the glow of connectivity to my new tiny silicone pet.
Thanks!

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