🛠 Premier script Python : piloter la LED depuis Python

Objectives

Write your first Python script on the ODROID-N2: turn a LED on and off controlled from Python via libgpiod (gpiod module), reusing the circuit from the LED tutorial. The S922X (4× Cortex-A73 + 2× Cortex-A53) runs Python 3 effortlessly under Armbian.

Hardware

• ODROID-N2/N2+ running Armbian, connected via SSH or screen and keyboard (HDMI 2.0)
• LED + 330 Ω resistor on PIN_23, GND on PIN_25
• sudo apt install python3-gpiod (or pip install gpiozero depending on the image)

Complete code

#!/usr/bin/env python3
"""clignotant.py — LED sur PIN_23 (GPIOX_11) via libgpiod, ODROID-N2."""
import gpiod, time

def main:
    with gpiod.Chip("gpiochip0") as chip:
        line = chip.get_line(chip.line_offset_to_name("PIN_23"))
        line.request(consumer="clignotant", type=gpiod.LINE_REQ_DIR_OUT,
                     default_val=0)
        try:
            for i in range(10):
                line.set_value(1); time.sleep(0.5)
                line.set_value(0); time.sleep(0.5)
                print(f"cycle {i + 1}/10")
        finally:
            line.release

if __name__ == "__main__":
    main

Expected verification

python3 clignotant.py prints cycle 1/10 to cycle 10/10 over 10 seconds while the LED blinks at 1 Hz, then the script terminates cleanly and the LED remains off. In case of AttributeError, check the libgpiod API version (python3 -c "import gpiod; print(gpiod.__version__)").

Common errors

• ModuleNotFoundError: gpiod: install python3-gpiod, not pip install gpiod (which is not the official binding).
• PermissionError on gpiochip0: missing gpio group or need to run with sudo.
• line_offset_to_name fails: the device-tree of the image does not expose PIN_xx names; list the lines with gpioinfo gpiochip0 and use the numeric offset.
• Forgetting line.release: the line remains occupied and blocks subsequent scripts.
• Confusing libgpiod v1 (Chip.find_by_name, gpio_line_request_output) and v2 (get_line) APIs: adapt to the installed binding.