MMM-Temperature/Humidity Module (DHT11, DHT22 and AM2302 sensors.)

[psk]

@cowboysdude DHT11 - This is the sensor that I am using.

It has three pins -
+ve - Connected to 5v
-ve - Ground
Data - Connected to pin 2

@Bangee Now, I am running as sudo npm start. Without sudo, it will throw an exception that says it cannot open dev/mem

This is the module screenshot.

[Bangee]

I’m using node-dht-sensor

As user pi I don’t have an error but after starting MagicMirror thers a crash.

@psk you should cool down your room :-)

[cowboysdude]

I really do like this! Great job!

[psk]

@Bangee According to bcm2835 v1.50-

"Running as root
Prior to the release of Raspbian Jessie in Feb 2016, access to any peripheral device via /dev/mem on the RPi required the process to run as root. Raspbian Jessie permits non-root users to access the GPIO peripheral (only) via /dev/gpiomem, and this library supports that limited mode of operation.

If the library runs with effective UID of 0 (ie root), then bcm2835_init() will attempt to open /dev/mem, and, if successful, it will permit use of all peripherals and library functions.

If the library runs with any other effective UID (ie not root), then bcm2835_init() will attempt to open /dev/gpiomem, and, if successful, will only permit GPIO operations. In particular, bcm2835_spi_begin() and bcm2835_i2c_begin() will return false and all other non-gpio operations may fail silently or crash."

So i guess we have run with sudo until some other library comes up :D

PS: I should!! Its too hot in here… :D :D

@cowboysdude Thanks! Cheers :D

[jsyzthz]

@psk i’m following your steps.but got some errors

can you help me to take a look? thanks!

[psk]

@jsyzthz I ran into the same while setting up!

try this. Go to MMM-Temperature-Humidity,

npm rebuild --runtime=electron --target=1.4.0 --disturl=https://atom.io/download/atom-shell --build-from-source

My Electron version is 1.4.0. If yours is different, replace accordingly. :D

This is a known issue which is caused by the serialport module using native code that is built for a different version of Node. You can read a bit more about addons here, if you’re interested; they’re just modules written in C/C++ that can interface with Node so the module can interface with the hardware more easily.

Credits : stackoverflow.com

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[psk]

@jsyzthz
I’m not sure whether to rebuild in MMM-Temperature-humidity directory or the Magic Mirror directory.
Try executing in the MagicMirror directory first.

npm rebuild --runtime=electron --target=1.4.0 --disturl=https://atom.io/download/atom-shell --build-from-source

Also you can find the electron version by : npm list

Just in case, i had this in my commands history :D
npm rebuild --runtime=electron --target=1.3.4 --disturl=https://atom.io/download/atom-shell --abi=49 -d

[jsyzthz]

@psk i use the first command. it woks now.thx!

[psk]

@jsyzthz Glad I could help :D :D

[H3L1o150]

Hi, i am really new on this, someone can help me, with the code on config.js file?

     {
                module: 'MMM-Temperature-Humidity',
                position: 'bottom_bar',
                config: {
                  var dht = new rpiDhtSensor.DHT11(21);
	    }
      },

thanks

[yawns]

@H3L1o150
No, you need to edit the file node_helper.js in the modules folder
Currently you cannot define the pin and the sensor type in the config section. But I think this should be improved in a future release

[H3L1o150]

@yawns so i left the config.js file like that?

  {
         module: 'MMM-Temperature-Humidity',
          position: 'top_right',
          config: {
               ...
      }
  }

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[yawns]

I never played around with this module. But I would use this:

{ module: 'MMM-Temperature-Humidity', position: 'top_right' }

And then you edit node_helper.js to set for DHT11 or DHT22 and the correct pin in ( )

[H3L1o150]

@yawns Tanks for the help

maybe i’m wrong in code. with me show a white screen

[psk]

@H3L1o150 currently, to define the pin to which sensor is connected, you need to edit the node_helper.js file ind MMM-Temperature-Humidity directory and edit line number 12.
var dht = new rpiDhtSensor.DHT11(2); to var dht = new rpiDhtSensor.DHT11(21);

you can leave the config as

            {
			module: 'MMM-Temperature-Humidity',
			position: 'bottom_right',
			config: {
				refreshInterval: 10000,
				temperaturePrefix: "Room temperature: ",
				temperatureSuffix: "°C",
				humidityPrefix: "Humidity: ",
				humiditySuffix: "%"
			}
		},

guess this needs to be improved in future release… :D

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[H3L1o150]

Tanks @psk

[jsyzthz]

i found MMM cannot auto startup if use it. because it must be run with sudo. but i don’t know how to run sudo with ‘DISPLAY=:0’? @psk

[Bangee]

@jsyzthz checkt this out: https://forum.magicmirror.builders/topic/738/mmm-dht22-humidity-and-temperature-module

[psk]

@jsyzthz Unfortunately neither did I have any luck executing with sudo while using ‘DISPLAY=:0’ .

For auto start I used PM2.

This is my mm.sh file

cd ~/MagicMirror
DISPLAY=:0 sudo npm start

P.S : I haven’t yet tried this alternative by Bangee. But it sure looks promising in this scenario where we need the mirror to start from ssh(or Terminal) while specifying the display device.

If i come across any workarounds, I’ll update.
Cheers.

[jsyzthz]

@psk , when i execute your command in my pi3 from putty. will get below error.