Burning a bootloader into the ATtiny3217 with the SerialUPDI Programmer.
The files are Eagle files
You can read the entire article here: https://avdweb.nl/arduino/attiny3217/bootloader-attiny3217
avandalen/SerialUPDI-Programmer
Burning a bootloader into the ATtiny3217 with the SerialUPDI Programmer
TypeScriptMIT