Read the statement by Michael Teeuw here.
MMM-DHT22 Humidity and Temperature Module
-
@ryck Hi. yes, a minute ago. He says “no data returned”.
-
@DocVooDoo sometimes the raspberry pi needs some time to pick up the values… try to increase the update time (ie, 30 seconds) and wait for it to update a couple of times…
-
@ryck nothing has changed. i have “node serveronly” running, and the log says “Error: failed to read sensor at Error (native)”
but the sensor works…
-
@DocVooDoo Weird… did you follow all the instructions? ie, install bcm2835, npm install, etc?
-
@ryck Yes of course.
-
@DocVooDoo No idea then… Can you paste here the error you get?
-
@ryck only this
then nothing on the log in node serveronly screen -
@DocVooDoo well, no idea then… Have you tried to run the normal version (instead of the serveronly)?
-
@ryck yes, the same problem…
-
@ryck is it possible that the module root rights needs but does not get?
with another module comes the same error. root privileges are needed there
-
@DocVooDoo I guess that depends on how you installed magicmirror… did you use sudo?
-
@ryck no, without sudo. only with the command
bash -c “$(curl -sL https://raw.githubusercontent.com/MichMich/MagicMirror/master/installers/raspberry.sh)” -
Some modules or dependencies require access to the GPIO
The DHT sensor module I wrote needs this as well.
In terminal please try this
sudo adduser -g $USER gpioI can’t remember if you need to reboot afterwards, but it won’t hurt. Then try again accessing the sensor
-
@yawns
Hi. Thanks for your help. The user “pi” is already a member of the group “gpio”.With Adafruit works the Sensor. Whether with or without sudo…
-
Any updates on this? I have the same problems as @DocVooDoo and others, i.e. Adafruit code works like a charm, dht_var not.
Difference I noticed is that dht_var uses wiringpi library and Adafruit not?! I tried a reinstall of wiringpi package without success.
Next, I compared the implementations of
dht_varand the Adafruit driver for DHT22.The essence of the Adafruit code is in file
Adafruit_Python_DHT/source/Raspberry_Pi_2/pi_2_dht_read.c. It is meant for Pi2 and Pi3, implemented in C, and defines a functionint pi_2_dht_read(int type, int pin, float* humidity, float* temperature). It implements the communication with the sensor using a 1-wire bus. The rest of the Adafruit package is mostly (well-done) sugar-coating for Python usage and selecting the right driver for any given platform.We could simply rewrite dht_var by using this driver code. What do you think?
Hello! It looks like you're interested in this conversation, but you don't have an account yet.
Getting fed up of having to scroll through the same posts each visit? When you register for an account, you'll always come back to exactly where you were before, and choose to be notified of new replies (either via email, or push notification). You'll also be able to save bookmarks and upvote posts to show your appreciation to other community members.
With your input, this post could be even better 💗
Register Login