This page is only for use with the High Voltage UPDI Friend. The simple UPDI Friend does not need these steps.

Before you upload code to your board with the High Voltage UPDI Friend, you'll need to edit the boards.txt file in the megaTinyCore board support package. This will enable the high-voltage fuses settings.

Install megaTinyCore

You can compile code for the ATtiny using the megaTinyCore board support package in the Arduino IDE. There are detailed installation instructions in the megaTinyCore GitHub repository. The following steps outline how to install it using the Boards Manager.

In the Arduino IDE, go to Preferences and add the megaTinyCore boards manager URL to the Additional Boards Manager URLs list:

Tools - Board - Boards Manager and search for megaTinyCore. Click Install to install the board support package.


Edit boards.txt

Navigate to the megaTinyCore board support package folder on your computer. This is usually located in the Arduino15 folder. For example, this is the file path for Windows: 


Open the boards.txt file in the folder with your preferred text editor.

Navigate to the "UPDI/RESET PIN CONFIGURATION" section in boards.txt:

Uncomment the last four lines in this section and save boards.txt. With these lines uncommented, you will brick chips that do not have a high voltage programmer, so proceed with caution.

If you uncomment these lines in boards.txt you will brick chips without the high voltage UPDI programmer.

Now you can proceed to upload the code to your board by following the steps on the Using the UPDI Friend page.

This guide was first published on Feb 05, 2024. It was last updated on Jun 25, 2024.

This page (Enabling Settings for the High Voltage UPDI Friend) was last updated on Jun 25, 2024.

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