Programming an Adafruit Gemma ATtiny85 on Mac OS 12 Monterey with Arduino IDE

Gemma_ATtiny85_Mac.md

Programming an Adafruit Gemma ATtiny85 on Mac OS 12 Monterey with Arduino IDE

This is for the black circuit board ADAFRUIT Gemma specfifically, not the arduino gemma.

Set Up Adafruit Boards

1. Open Arduino IDE (I'm using 2.0.3)
2. Open Adafruit IDE -> Preferences
3. Add this URL to the Additional boards manager URLs https://adafruit.github.io/arduino-board-index/package_adafruit_index.json 4. Click the two squares icon at the right of the text box 5. Paste the URL in the box. If you've got others in there, paste it on a new line 6. Click OK

Select board and programmer typ

1. Open the Blink sketch example. File -> Examples -> Basics -> Blink
2. Select ADAFRUIT Trinket as your board type
   • Tools -> Board -> ADAFRUIT AVR Boards -> Adafruit Gemma (ATtiny85 @ 8MHz)
   • Yes, my board is a Gemma but if I look in the USB section of the System Information app in MacOS, it shows that the mac sees it as a Trinket. Odd.
3. Select USBtinyISP as your programmer. Tools -> Programmer -> USBtinyISP

Program the Adafruit Gemma

1. Plug in the board via USB, and turn the power switch on.
2. Press the button.
3. Wait until the red D1 LED Blinks quickly.
4. Go to Sketch -> Upload Using Programmer
   • The normal upload button doesn't work!
5. Cross your fingers.

I still get some of the following errors, but if I keep trying it eventually goes through.

• usbtiny_receive: Broken pipe
• usbtiny_send: Operation timed out
• avrdude: verification error;
• avrdude: Expected signature for ATtiny85 is 1E 93 0B

I don't know if it's just suspicion at this point but maybe it's more likely to go through if I turn it off and on again, press reset then wait 5s before trying to upload.