The mEDBG (ATmega32U4) JTAG interface is available for programming and debugging of the ATmega32U4 on the 50-mil header in the upper right corner of the kit.
| J100 Pin | Signal Name | Description |
|---|---|---|
| 1 | TCK | |
| 2 | GND | |
| 3 | TDO | |
| 4 | VCC_BOARD | ATmega32U4 VCC (J301 pin 2) |
| 5 | TMS | |
| 6 | RESET | Connected to ATmega32U4 only |
| 7 | NC | |
| 8 | NC | |
| 9 | TDI | |
| 10 | GND |