| Input |
Components |
Pins |
Connection |
| Button |
Momentary switch |
GP0–1, GP4–22 |
Switch between GPIO and GND (internal pull-up, no resistor needed) |
| Touch |
Conductive pad (copper tape / foil / bare PCB) |
GP0–1, GP4–22 |
Pad connected to GPIO only (capacitive sensing, no GND) |
| Pot |
Potentiometer (any value) |
GP26, 27, 28 |
Outer legs to 3V3 + GND, wiper to ADC pin |
| LDR |
LDR + 10kΩ resistor |
GP26, 27, 28 |
Voltage divider: 3V3 → LDR → midpoint → ADC pin, resistor → GND |
| Accel |
LIS3DH or MPU6050 module |
GP2 (SDA), GP3 (SCL) |
I2C: SDA/SCL to GP2/GP3, VCC to 3V3, GND to GND |