Firmware ↔ rev H pin map
Defines live in toern.ino. Net names below match the rev H netlist (PCB/toern_revH/toern_revH.net). The schematic PDF wins if a silk label disagrees.
Core defines
| Firmware | Teensy pin | Board use |
|---|---|---|
DATA_PIN | 17 | WS2812 data. Series R20 (220 Ω) then J9 pin 1 |
INT_PIN | 27 | Shared encoder interrupt (pad 5 on encoder sockets) |
INT_SD | 10 | microSD chip-select |
SWITCH_1 | 2 | Touch / TTP223 — single mode |
SWITCH_2 | 3 | Touch — menu |
SWITCH_3 | 4 | Touch — record |
SWITCH_4 | 6 | Extra switch net (board-dependent) |
SWITCH_5 | 39 | Extra switch net (board-dependent) |
BATT_ADC_PIN | A16 (40) | VBAT divider |
MIDI on Serial8 uses pins 34/35 (RX8/TX8) with enlarged buffers — TRS jacks go through the opto / buffer stage (TLP2361 U4, Schmitt 74LVC2G14 U5).
Buses (by convention)
| Bus | Pins | Devices |
|---|---|---|
| I²C0 | 18 / 19 | Encoders + SGTL5000 control |
| SPI (SD) | 10–13 | microSD J8 |
| I²S (codec) | (Audio library defaults on Teensy 4 + SGTL wiring) | U3 data/clocks — see schematic |
| USB | D+/D− pads on U6 | USB-C J4 via pogo pins CN1 (D−) and CN2 (D+) |
When changing pins
- Update the PCB net / jumper and the
#defines. - Re-check encoder INT (must be common open-drain style as wired).
- Re-check SD CS vs any other SPI CS uses.
- Battery divider in firmware must match the assembled resistors. On rev H that is R15 1 MΩ (VBAT → A16) and R19 1.5 MΩ (A16 → GND).