• This code is for Atmel AVR ATtiny9
  • Connect ESP-EN to PortB0
  • Connect ESP-Boot0 to PortB1
  • Connect ESP-RxD0 to PortB2
  • Only a baudrate of 115200 is supported at this point
  • Do not program the ATtiny9 when the ESP32 is connected to the TPI lines
  • ATtiny9 needs 5 V to program but can run on 3.3 V
  • Outputmodes can be chosen between pushpull and opencollector at compiletime (see config.h)
  • RxD pin pullup can be chosen at compiletime (see config.h)
  • The baudrate is calibrated within a certain range
  • Arduino bootsequence to test with HTERM in HEX format: "C0 00 08 24 00 00 00 00 00 07 07 12 20 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 C0"