Troubleshooting

If you get the error message avrdude: Error: Could not find USBtiny device (0x1781/0xc9f)

That means the bootloader wasn't active. Make sure to press the button on the Trinket to activate the bootloader before clicking the Upload button.

If you get a lot of red text, errors and also a warning about Verification Failed

Check that you updated the avrdude.conf file above - if you don't update the description of the Attiny85 in the configure file by replacing it, the IDE wont know to be patient with the Trinket/Gemma bootloader and will have many upload errors

On Linux if you get the error message "usbtiny_receive: error sending control message: Protocol error (expected 4, got -71)"

These can generally be ignored and should not interfere with the program upload.  Unfortunately Linux's USB core is a little flakey communicating with the ATtiny85 processor on the Trinket/Gemma and can cause these errors.  If an upload does fail, try it again as it is likely an intermittent issue.

This guide was first published on Apr 05, 2015. It was last updated on Oct 18, 2018. This page (Troubleshooting) was last updated on Nov 20, 2015.