Expansion Headers¶
PuffiAir’s PCB provides two expansion headers, designed for advanced users who wish to connect external components, sensors, or modules.
Header A — I²C Expansion Port¶
This header exposes the onboard I²C bus, allowing connection to external I²C-compatible sensors.
| Pin | Description |
|---|---|
| GND | Ground |
| SCL | I²C Clock Line (GPIO 23) |
| SDA | I²C Data Line (GPIO 22) |
| 3V3 | 3.3V Output |
| 5V | 5V Output |
Notes:
- Logic level: 3.3V
- Make sure your external device is I²C address-compatible
- Avoid connecting multiple devices with the same I²C address
Header B — General Purpose I/O¶
This header allows for connecting GPIO-controlled accessories, such as: LED strips
| Pin | Description |
|---|---|
| 5V | Power supply |
| D12 | GPIO 7 |
| C12 | GPIO 5 |
| GND | Ground |
| 3V3 | 3.3V power |