DHT22 and DuetWifi

  • I'm trying to hook up a DHT22 (well, technically a AM2302) to my DuetWifi.
    I used https://duet3d.com/w2/images/0/0b/Duet2ndGen_connectionsv1.4.png:

    • Expansion Pin 3: 3.3V

    • Expansion Pin 2: GND

    • Expansion Pin 9: Data

    Expansion Pin 9 is labeled "E3_STOP", and according to https://duet3d.com/wiki/DuetWifi_Pinout_table, this is "CS6", and https://duet3d.com/wiki/G-code#M305:_Set_temperature_sensor_parameters says to use that.

    Side note for DC42: there are two E3_STOPs in the pinout table - I guess Pin 98 should be E4_STOP?

    So now I try to setup the virtual heater so I see my DHT22 temp+humidity in DWC. Channel 400 & 401 are Temperature and Humidity of the DHT22.
    I guess this has to be a virtual heater, and 100,101,102 are already taken, so I wanted to start with 103.

    M305 P103 X400 T22 S"Ambient"
    Error: unable to use sensor channel 400 on heater 103

    Unfortunately this error messages doesn't really tell me much. Did I use the wrong pins and the communication failed? Did I use an invalid heater number? Do I need to setup a chamber heater first?

    Any help would be much appreciated!

  • /me …mhm I should probably add my firmware version to this post...
    /me Doh!

    I'm using 1.19. No wonder it didn't work 😛
    DHT support was added with one of the 1.20 betas.

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