The nRF9161 DK has an I/O expander that can optionally be used to interface the LEDs and buttons.
| Signal | GPIO | Description |
|---|---|---|
| SDA | P0.30 | I2C data line |
| SCL | P0.31 | I2C clock line |
| IOEXP_IRQ | P0.19 | Interrupt line from the I/O expander |
The following table shows the I/O expander connections.
| Component | I/O expander pin |
|---|---|
| LED 1 | I/O_EXP_IO4 |
| LED 2 | I/O_EXP_IO5 |
| LED 3 | I/O_EXP_IO6 |
| LED 4 | I/O_EXP_IO7 |
| Button 1 | I/O_EXP_IO0 |
| Button 2 | I/O_EXP_IO1 |
| Button 3 | I/O_EXP_IO2 |
| Button 4 | I/O_EXP_IO3 |
The following figure shows the I/O expander connections.
Figure 1. I/O expander
