I’m very excited about using the Adafruit Trinkets, which are essentially small breakout boards for the Atmel ATtiny85 microcontroller. It is intended to be used with the Arduino IDE (and I hoped this would be easy), and I found this to work well for compiling source code into a HEX file. However, I was never successful getting the upload to work directly with Arduino IDE. At this point, I learned to use avrdude from the command line (I’ve been working in Windows XP up to this point, but I’m switching to Ubuntu since MS doesn’t support XP anymore).
I followed the instructions from Adafruit given here. These are well written and got me a long way. I only had trouble uploading with avrdude.
I found this to be a two step process:
1. I used this command to clear the on-chip flash: avrdude -c usbtiny -p attiny85 -U flash:w:<hexfile.hex>
This would flag tons of errors that would require a CTRL-C to stop.
2. Then run this similar command: avrdude -c usbtiny -p attiny85 -D -U flash:w:<hexfile.hex>
This will actually write to the flash. If you don’t do step 1, you will get a verification error.
Once the chip was programmed, everything worked well. Many of the Arduino commands work with the ATtiny85.