OpenWrt Forum Archive

Topic: Any humidity sensor for Openwrt?

The content of this topic has been archived on 25 Apr 2018. There are no obvious gaps in this topic, but there may still be some posts missing at the end.

Hello,

Have anyone successfully added an humidity sensor to a openwrt router?
I have a openwrt router with I2C (PCF8574) and 1-W (DS18B20), and now the next step would be to acquire humidity values, but it seems there is nothing about it around...

Any idea?

Thanks in advance,
jabss

There should be combined temperature and humidity sensors called SHT10 or SHT15. And, from what I recall, Honeywell has got some in their HIH series. Have a look at the hwmon section of the kernel to see what's already supported by the kernel, or of openwrt to see what's included.

What would be the easiest way to connect a humidity sensor to Openwrt? I'm thinking about using an Arduino and DHT22, but is there some way to connect a DHT22 (or some other cheap sensor) directly to a GPIO pin on Openwrt? I guess the problem is that there are no drivers for DHT22 in Openwrt?

Easiest might be some USB connected humidity sensor with Linux-support (assuming that your router has an USB port).

Googling https://www.google.com/search?q=humidit … +usb+linux produced this as the first result:
http://dograt.homelinux.com:8080/produc … -tnh-sht10
Linux drivers are provided as GPL source code, so it could probably work in Openwrt environment.

Something like that would probably be easiest as it would not require hardware modifications (and most likely no kernel modifications).

Hello,

Meanwhile I was able to easily add a DHT-22 humidity/temperature sensor to my RaspberryPI and didn't need to use it on my OpenWrt router.

Anyway, if you install phython in your router, I guess this would work.

Cheers,
Jabss

Alternative solution in case money doesn't matter that much and in case you already have 1-wire environment installed: google for "OW-ENV-THPL"

There are multiple sensors available, with THPL being the one who has the most sensors (i.e. Temperature, humidity, barometric pressure, light intensity (lux)). There are other sensors available with only T + Rh which cost less.

Yes, those sensors aren't exactly cheap, but installation and readout is quite easy.

One more drawback regarding 1-wire: owfs in combination with a DS9490R busmaster is quite unstable, so you have to take care of this instability in your readout scripts.

Hi there!

A humidity & temperature sensor would be funny to play with smile
The DHT11 / DHT22 look quite promissing, due to their low prices, but i was wondering wether someone got this working on openWrt or not?

I'm quite new to openWrt and GPIO but i'd like to get a little more into this.

Therefor: What hardware does have GPIO pins and might be working with one of those two sensors?

The devel mailing list at:
https://lists.openwrt.org/pipermail/ope … 28232.html
states: " + support for DHT11 and DHT22 digitial humidity and temperature"

so i hope the sensors could work; hardware seems to be a problem though.


Any ideas or thoughts about this?

Thanks in advance!
Z oc om

jabss wrote:

Meanwhile I was able to easily add a DHT-22 humidity/temperature sensor to my RaspberryPI and didn't need to use it on my OpenWrt router.

Did you mean this DHT22 digital temperature and humidity sensor?

I guess he did, i ordered 2 of them, takes 2-3weeks until they arrive here  ....

What do you think, could the VoCore be used for this?
http://vocore.io

another idea is the next:

-a temperature/humidity sensor from a wireless weather station and receive its signal with a RTL2832U dongle (DVB-T usb dongle that can be used in "SDR - Software Defined Radio")  in a openwrt router with "rtlsdr" package installed.

I plan on giving one of the supported sensors of si7020 a try some day. They promise great resolution and accuracy. You would just have to include the module into your firmware.

I bought a bunch of DHT11 sensors to test with a GL.iNet device and wondering if there are others that have GPIO ports already pinned. Anyone get the DHT11 to work?

The discussion might have continued from here.