Not possible to get data from DHT22

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Hello everybody,

I have a major problem with the DHT22, the sensor is shown as unkonwn in pimatic!
The BCM2835 library v1.5 is installed as well as the wiringPi and the pimatic-dht22-sensors plugin. I used a Raspberry Pi 3 B.
It´s possible to get the data with loldht and the values are comprehensible.
I´m the Raspbian build 2016-09-23 and a DHT22 module with pre-installed resistors.
But all data I got in pimatic is UNKNOWN at Humidity and Temperature!

I have installed the whole system 2 times to avoid installation failures depending on the installation order from the plugins and the library.

The system is for a temeperature control from a terrarium and should work with 2 DHT22
and a USB controlled 230VAC socket strip.

I hope for some quick suggestions or a tutorial for my special case.

Kind regards.

Eric

@Eric-B. said in Not possible to get data from DHT22:

I hope for some quick suggestions or a tutorial for my special case.

I have a working setup with a DHT11 and DHT22 sensor, both connected via GPIO using pimatic-dht-sensors. PIN number is wiringX by default, but you can also switch to BCM numbering if this preferred. See also: https://forum.pimatic.org/topic/2404/important-note-for-pimatic-dht-sensors
Here is my device config:

   {
      "type": 11,
      "pin": 2,
      "xAttributeOptions": [],
      "id": "dht2",
      "name": "dht2",
      "class": "DHTSensor"
    },
    {
      "type": 22,
      "pin": 7,
      "xAttributeOptions": [],
      "id": "dht1",
      "name": "dht1",
      "class": "DHTSensor"
    },

Well, I don´t know why but now it works…?
I installed the whole system the 3rd time in the following order:

1. raspbian
2. raspi-config for localisation things
3. sudo apt-get update && sudo apt-get upgrade
4. installing node 4.4.5
5. installing wiringPi v2
6. installing BCM2835 library
7. installing pimatic
8. installing plugins:
   -cron
   -dht-sensors
   -mail
   -mobile-frontend
   -shell-execute
   -sispmctl
   -sunrise

Until now the autostart doesn`t work, I have to figure it out, once again…!
Any suggestions on that? It´s not possible to start the service…?

Thanks once again in advance.

Kind regards

Eric

hey eric!
i guess you followed the installation procedures step by step including the autostart
maybe try to update to node 4.6.2., click here for howto don’t know if it is related to that, but without more information on debug data or logfiles it’s like looking into crystal balls

@leader21 Thx for the suggestion, I install it anyway!

But now after connecting the 2nd DHT22 I have the same problem again!
The config file for this devices is shown below:

devices": [
    {
      "id": "sensor_oben",
      "name": "dht22_1",
      "class": "DHTSensor",
      "type": 22,
      "pin": 3,
      "interval": 5000,
      "xAttributeOptions": []
    },
    {
      "id": "sensor_unten",
      "name": "dht22_2",
      "class": "DHTSensor",
      "type": 22,
      "pin": 7,
      "interval": 5000,
      "xAttributeOptions": []
    }

With loldht I can see the temperature from all 2 devices, but in the frontend of pimatic I only see the dht22_2 with the temperature and humidity data. The data from dht22_1 is shown as unknown.

What could be the problem?
Let me know if you need more information or debug (log) files!

Kind regards
Eric

Edit:
Now the 2nd device shows me 0°C/0%.
The wiring is as follows:
DHT22_1 +5V/Pin 7/GND
DHT22_2 +5V/Pin 11/GND
I changed the devices vice versa, without success…!

@Eric-B. Did you already update to pimatic-dht-sensors version 0.9.3? If not, please do so, as this release contains and important fix which may resolve the problem.

@Eric-B. said in Not possible to get data from DHT22:

DHT22_1 +5V/Pin 7/GND
DHT22_2 +5V/Pin 11/GND

This looks odd to me! Please refer to BCM GPIO numbers as shown in the diagram at http://wiringpi.com/pins/ (see below) and make sure you are using the right PIN numbers. In other words, BCM GPIO 7 and 11 (if this is what you’ve connected to) map to WiringPI 11 and 14

Thanks for the replies, I will look ASAP at it! I already update the plugin, Pimatic and node.js to the all new versions!