First install the dtoverlay driver in linux
Connect DHT11 VCC to 3.3V
Connect DHT11 GND to GND
Connect DHT11 DAT pin to an unused GPIO PIN.
On my example I choose GPIO21
Now install the DTOVERLAY DHT11
type sudo nano /boot/firmware/config.txt
Just after the [ALL] add this lineCTRL-x and yes to save
Reboot
Now you should see the DHT11 sensor appears "/sys/bus/iio/devices" folderif iio:device0 exist then you sensor works!
And this is a small script to access the DHT11 via python
The result
Connect DHT11 VCC to 3.3V
Connect DHT11 GND to GND
Connect DHT11 DAT pin to an unused GPIO PIN.
On my example I choose GPIO21
Now install the DTOVERLAY DHT11
type sudo nano /boot/firmware/config.txt
Just after the [ALL] add this line
Code:
[all]dtoverlay=dht11,gpiopin=21Reboot
Now you should see the DHT11 sensor appears "/sys/bus/iio/devices" folder
Code:
daniel@Pi5:~ $ cd /sys/bus/iio/devicesdaniel@Pi5:/sys/bus/iio/devices $ lsiio:device0daniel@Pi5:/sys/bus/iio/devices $ cd iio:device0daniel@Pi5:/sys/bus/iio/devices/iio:device0 $ lsin_humidityrelative_input name power ueventin_temp_input of_node subsystem waiting_for_supplierdaniel@Pi5:/sys/bus/iio/devices/iio:device0 $ cat in_humidityrelative_input 36000daniel@Pi5:/sys/bus/iio/devices/iio:device0 $ cat in_temp_input 20000daniel@Pi5:/sys/bus/iio/devices/iio:device0 $ And this is a small script to access the DHT11 via python
Code:
#!/bin/python3import timedevice0 = "/sys/bus/iio/devices/iio:device0"#function to read first line and return integerdef readFirstLine(filename): try: f = open(filename,"rt") value = int(f.readline()) f.close() return True, value except ValueError: f.close() return False,-1 except OSError: return False,0try: while True: Flag, Temperature = readFirstLine(device0+"/in_temp_input") print("Temperature:",end="") if Flag: print(Temperature // 1000,"\u2103",end="\t") else: print("N.A.",end="\t") Flag, Humidity = readFirstLine(device0+"/in_humidityrelative_input") print("Humidity:",end="") if Flag: print(Humidity // 1000,"%") else: print("N.A.") time.sleep(2.0)except KeyboardInterrupt: passCode:
daniel@Pi5:~ $ python readDHT11.pyTemperature:27 ℃Humidity:31 %Temperature:26 ℃Humidity:32 %Temperature:26 ℃Humidity:32 %Temperature:26 ℃Humidity:32 %Temperature:26 ℃Humidity:32 %Temperature:26 ℃Humidity:32 %^Cdaniel@Pi5:~ $ Statistics: Posted by danjperron — Sat Feb 24, 2024 6:35 pm