OctoPrint-Enclosure icon indicating copy to clipboard operation
OctoPrint-Enclosure copied to clipboard

DHT22 Temp sensor on Pi 4

Open pman92 opened this issue 2 years ago • 3 comments

Hey guys, I've recently changed from using a pi 3b+ to a pi 4b. I previously had a DHT22 temp sensor working with the enclosure plugin on the 3B+. Its now connected the same (to GPIO 4) on the 4B but I cannot get it to work.

  1. I have SSH'ed and installed the adafruit-circuitpython-dht and libgpiod2 as described in the enclosure plugin readme.
  2. I have tried disabling "use SUDO" in enclosure plugin advanced settings (as I had to do that to get it working on the 3B+, but it made no difference on the 4B).
  3. I have tried the adafruit sample code, and get the following: pi@octopi:~ $ python3 dht_simpletest.py Traceback (most recent call last): File "dht_simpletest.py", line 5, in <module> import board File "/home/pi/.local/lib/python3.7/site-packages/board.py", line 44, in <module> from adafruit_blinka.board.raspberrypi.raspi_4b import * File "/home/pi/.local/lib/python3.7/site-packages/adafruit_blinka/board/raspberrypi/raspi_4b.py", line 6, in <module> from adafruit_blinka.microcontroller.bcm2711 import pin File "/home/pi/.local/lib/python3.7/site-packages/adafruit_blinka/microcontroller/bcm2711/pin.py", line 5, in <module> from RPi import GPIO ModuleNotFoundError: No module named 'RPi'

pman92 avatar Oct 15 '22 06:10 pman92

I fixed the "no module found" error by running "sudo apt install python3-rpi.gpio". However the sensor still doesn't work, I now get "DHT sensor not found, check wiring" from the adafruit test script.

The sensor is connected to GPIO4 (pin 7). Inside the script I have: dhtDevice = adafruit_dht.DHT22(board.D4) and have also tried: dhtDevice = adafruit_dht.DHT22(board.D4, use_pulseio=False)

pman92 avatar Oct 15 '22 08:10 pman92

Have got it working. After finding this, I installed the following: pip3 install sysv-ipc And now the sensor is working fine in both octoprint and the test script.

I still require "use SUDO" to be disabled under advanced settings like I did with the 3B+. Which makes sense because if a run the test script as sudo it still says sensor not found.

pman92 avatar Oct 15 '22 09:10 pman92

i had this issue but manged to get rounf that im using the dht11 sensor and its reading temp and humi but to dislaying the values on my octoprint

burnerbmx avatar Jul 02 '23 23:07 burnerbmx