DHT22 unable to view readings

[davbcr]

Despite proper configuration of the plugin it's not able to show any readings from DHT22 properly connected and working.

SUDO in advanced settings is disabled getDHTTemp.py is below:

import sys import Adafruit_DHT

Parse command line parameters.

sensor_args = { '11': Adafruit_DHT.DHT11, '22': Adafruit_DHT.DHT22, '2302': Adafruit_DHT.AM2302 } if len(sys.argv) == 3 and sys.argv[1] in sensor_args: sensor = sensor_args[sys.argv[1]] pin = sys.argv[2] else: sys.exit(1)

humidity, temperature = Adafruit_DHT.read_retry(sensor, pin,2,0.5)

if humidity is not None and temperature is not None: print('{0:0.1f} | {1:0.1f}'.format(temperature, humidity)) else: print('-1 | -1')

sys.exit(1)

Can you help me modify getDHTTemp.py to get readings? i've noticed that with the script of Raspcontroller App here attached it works. dht_v6.txt

[noz1380]

I have the same issue, and wanting to fix. I'm not sure if this is still supported?

I have read that there is a change in an update, and adafruit dont support the old DHT, but the newer Adafruit_CircuitPython_DHT

https://stackoverflow.com/questions/63232072/cannot-import-name-beaglebone-black-driver-from-adafruit-dht

[noz1380]

Please take a look at this thread.

https://stackoverflow.com/questions/63232072/cannot-import-name-beaglebone-black-driver-from-adafruit-dht

I added this line as per the instructions

elif match.group(1) == 'BCM2711': return 3

It works!!------Sorry it works on command line, which is better than I had before.

But not in Octoprint.

[davbcr]

Please take a look at this thread.

https://stackoverflow.com/questions/63232072/cannot-import-name-beaglebone-black-driver-from-adafruit-dht

I added this line as per the instructions

elif match.group(1) == 'BCM2711': return 3

It works!!------Sorry it works on command line, which is better than I had before.

But not in Octoprint.

Mee too. it's not working via Octoprint. I've tried also to add import Adafruit_CircuitPython_DHT into gettempdht.py but it seems needed a different configuration of the file.....and i get it not to work from command line either, rolling back stuck again.

[noz1380]

What I cant figure out is that the example code to show temp and humidity (sudo ./AdafruitDHT.py 2302 4) in terminal is pretty much identical to the code in "getDHTTemp.py" which leads me to think there is a problem elsewhere.

[unsplorer]

I'm running OctoPrint in a docker container and was able to resolve this issue by installing the newer Adafruit_CircuitPython_DHT library and python3 inside the container. I had to adjust the call to getDHTTemp.py inside octoprint_enclosures init.py to use python3. I then had to modifiy getDHTTemp.py for the newer CircuitPython library as follows :

   import adafruit_dht
   from board import D19 #my sensor is connected to D19 on RPi. adjust your pin accordingly
   import time

   # Parse command line parameters.
   sensor_args = { '11': adafruit_dht.DHT11,
       '22': adafruit_dht.DHT22}
   #        '2302': Adafruit_DHT.AM2302 } depreciated
   if len(sys.argv) == 3 and sys.argv[1] in sensor_args:
       sensor = sensor_args[sys.argv[1]]
       pin = sys.argv[2] #ignoring this for testing purposes
   else:
       sys.exit(1)

   dht_device = adafruit_dht.DHT22(D19)

   read_attempts = 0
   while read_attempts < 7: # try for a reading 7 times since dht's are unreliable
          try:
                  humidity = dht_device.humidity
                  temperature = dht_device.temperature

                  if humidity is not None and temperature is not None:
                      print('{0:0.1f} | {1:0.1f}'.format(temperature, humidity))
                      sys.exit(1)
          except RuntimeError as error:
                  read_attempts += 1
                  time.sleep(2.0)
                  continue
          except Exception as error:
                  read_attempts += 1
                  dht_device.exit()
                  raise error

          time.sleep(2.0)

   print('-1 | -1')
   sys.exit(1)