# GPIOD user guide

***Copyright © Quectel Wireless Solutions Co., Ltd. 2026. All rights reserved.***

---

Common commands for inspecting and controlling GPIO using gpiod tools on Quectel Pi. The currently connected development board has been verified with libgpiod v1.6.3.

# Installation and Verification

```bash
sudo apt update
sudo apt install -y gpiod
gpiodetect --version
gpiodetect
gpioinfo
```

| **Command** | **Purpose** |
| --- | --- |
| `gpiodetect` | View GPIO controllers |
| `gpioinfo` | View GPIO line status and usage |
| `gpioget` | Read input state |
| `gpioset` | Set output state |
| `gpiomon` | Monitor edge events |

# Controller Identification

Example output from the current development board is shown below. For actual projects, refer to the output from the board in use.

```
gpiochip0 [400000.pinctrl] (114 lines)
gpiochip1 [1c40000.qcom,spmi:qcom,pm6125@0] (9 lines)
gpiochip2 [soc:spf_core_platform:lpi_pinct] (19 lines)
```

# Common Commands

```bash
# View lines on the primary controller
gpioinfo /dev/gpiochip0

# Read line 36 of gpiochip0
gpioget gpiochip0 36

# Set output high and hold for 5 seconds
gpioset --mode=time --sec=5 gpiochip0 36=1

# Monitor rising-edge events
gpiomon --rising-edge gpiochip0 36
```

# Version Differences

| **Function** | **Current v1 Syntax** | **Syntax That May Appear in Newer Documentation** |
| --- | --- | --- |
| Read | `gpioget gpiochip0 36` | `gpioget -c gpiochip0 36` |
| Hold Output | `gpioset --mode=time --sec=5 gpiochip0 36=1` | `gpioset -c gpiochip0 -p 5s 36=1` |
| Rising-edge Monitoring | `gpiomon --rising-edge gpiochip0 36` | `gpiomon -c gpiochip0 -e rising 36` |

# Notes

- GPIO line offset is not the same as the physical header pin number.

- Lines marked `[used]` or already having a consumer should not be controlled directly.

- After the `gpioset` process exits, the output state may revert to the default. Do not rely on the residual level after the process exits.