emonTH wireless temperature & humidity sensor with SI7021 sensor
Clone or download
Latest commit 37826d0 Oct 26, 2018
Type Name Latest commit message Commit time
Failed to load latest commit information.
datasheets add datasheets Sep 20, 2016
docs battery capacity is 2xAA because of boost converter Oct 4, 2016
firmware define monitor baud Oct 26, 2018
hardware Update readme.md Dec 5, 2017
sensor emonth2 blog Nov 30, 2016
.gitignore update Sep 24, 2016
.travis.yml skip cleanup for deploy Nov 16, 2016
20170117_emonth_v2_0_2.csv add emonth2 octopart bom Jan 17, 2017
LICENSE Initial commit Sep 24, 2016
readme.md add emonupload Feb 5, 2018


emonTH V2.0

Build Status

Low power wireless temperature and humidity node

V2.0 hardware revision adds support for SI7021 temperature and humidity. This sensor brings performance and power savings over the DHT22, see sensor folder of this repo for sensor evaluation and comparison.

The emonTH V2 is an open-source, wireless, battery powered temperature and humidity monitoring node.

Data from the emonTH is transmitted via wireless RF (433MHz) to an emonPi / emonBase web-connected base-station for logging to Emoncms for data logging, processing and graphing.

emonTH V2


  • Hardware schematic & CAD files are in the hardware folder of this repo
  • See emonTH V1 Technical Wiki for more hardware design notes.

Related Blog Posts

Related Forum Posts



Either upload pre-compiled firmware (from github releases) using our emonUpload tool or compile and upload

Compile & Upload

PlatformIO is recommended as the easiest way to compile and upload Arduino compatible firmware for emonTH. One of the big advantages of using PlatformIO is all libraries can be automatically downloaded. Arduino IDE can also be used but libraries must be manually installed.

Compile & Upload Firmware Using PlatformIO

For a full guide and installing and using PlatformIO (including visual IDE) see 'Compiling' User Guide Section. Assuming platformIO is installed

$ git clone https://github.com/openenergymonitor/emonth2
$ cd emonth2
$ pio run
$ pio -t upload


emonTH hardware is fully open-source. See hardware folder of this repo for Gerbers, Eagle CAD design, BOM & port map.