capteur-dht11.py
The Adafruit CircuitPython driver runs on stock Linux: it bit-bangs the DHT 1-wire protocol through libgpiod. The script prints temperature and humidity every 2 s, shrugging off invalid frames without crashing.
Hardware
A Radxa Zero 3W (Rockchip RK3566 quad Cortex-A55, 1-4 GB) in a stick form factor, with Wi-Fi 5, Bluetooth and a 40-pin header. 1 DHT11/DHT22 sensor + 10 kΩ resistor (3-pin module: already built in).
Wiring
VDD to 3.3 V, DATA to the script pin (GPIO4) with a 10 kΩ pull-up to 3.3 V, GND to GND.
How it works
adafruit_dht drives the protocol through the kernel (use_pulseio=False): start pulse, microsecond timing, decoding. Periodic failures are normal on the DHT11.
Running it
On the Radxa image: apt install gpiod python3-gpiod; gpiodetect/gpioinfo to identify the GPIO chip of the 40-pin header, then run the script.
Variants
Log to CSV with the cron script, or expose readings over the network with the built-in web server on port 8080.
capteur-dht11.py
#!/usr/bin/env python3
# DHT11/DHT22 via adafruit-circuitpython-dht (pilote en noyau ou bit-bang).
# Installation :
# sudo apt install python3-dev python3-venv libgpiod2
# python3 -m venv ~/.venv && source ~/.venv/bin/activate
# pip install adafruit-circuitpython-dht
import time
import board
import adafruit_dht
# Broche physique 7 (GPIO4 sur connecteur standard 40 broches) :
capteur = adafruit_dht.DHT11(board.D4, use_pulseio=False)
# DHT22 : adafruit_dht.DHT22(board.D4, use_pulseio=False)
print("Ctrl-C pour arreter")
while True:
try:
t = capteur.temperature # degres Celsius
h = capteur.humidity # % HR
print(f"T = {t:0.1f} C | HR = {h:0.1f} %")
except RuntimeError as erreur:
# Le DHT rate parfois une trame : normal, on recommence.
print("trame invalide:", erreur.args[0])
time.sleep(2.0)