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Wire setting for my heat sensor with rpi3 b plus

Posted: Wed Oct 03, 2018 7:01 am
by Rimbik
I got a heat sensor (DHT11 - Temprature and Humidity Sensor Module, EC-0442) with 3 wires red, yellow, brown colored.
I can see in sensor it has mark plus, minus but not sure which wire to put where.
Brown I guess is Data, Is Red + ? or then which one is - ?

Is yellow negative?

I am fitting this heat sensor to my Rpi 3 GPIO pin

Please suggest,

Re: Wire setting for my heat sensor with rpi3 b plus

Posted: Wed Oct 03, 2018 2:47 pm
by drgeoff
Consult the spec sheet for the module or ask the vendor. Google isn't finding me anything relevant for "EC-0442 temperature".

Re: Wire setting for my heat sensor with rpi3 b plus

Posted: Thu Oct 04, 2018 11:11 am
by danjperron
The DHT111 use a special serial protocol. It's not I2c and it is not TTL serial.


Check this old post that I made a long time ago.
https://www.raspberrypi.org/forums/view ... 49#p671849

You could use pigpio to read it. There is also a kernel driver but I prefer Joan's version with pigpio.

Re: Wire setting for my heat sensor with rpi3 b plus

Posted: Thu Oct 04, 2018 4:29 pm
by RattusRattus
Differant modules will have differant pin-outs.
The best you can do is use a multi-meter to 'buzz-out' the pins.

The DHT11 data sheet tells you the pin numbering for the sensor itself:
Pin Description
1, the VDD power supply 3.5~5.5V DC
2 DATA serial data, a single bus
3, NC, empty pin
4, GND ground, the negative power

Your module is likly to just connect these pins to your wires. Connect the multimeter (in either diode test or resistance modes) between each pin and each wire to find which is which on YOUR (undocumented) module

/Andy

Re: Wire setting for my heat sensor with rpi3 b plus

Posted: Thu Oct 11, 2018 4:23 pm
by Rimbik
RattusRattus wrote:
Thu Oct 04, 2018 4:29 pm
Differant modules will have differant pin-outs.
The best you can do is use a multi-meter to 'buzz-out' the pins.

The DHT11 data sheet tells you the pin numbering for the sensor itself:
Pin Description
1, the VDD power supply 3.5~5.5V DC
2 DATA serial data, a single bus
3, NC, empty pin
4, GND ground, the negative power

Your module is likly to just connect these pins to your wires. Connect the multimeter (in either diode test or resistance modes) between each pin and each wire to find which is which on YOUR (undocumented) module

/Andy
Thank you for the update, Now I guess since I am deploying it with VS 2017 remotely with Wifi and IP Address, there is no display attached to Pi, and am expecting I will see it my Visual Studio, That may be wrong assumption. I will connect my pi to projector and will check, Thank you all :-)