View source for I2C Hardware

It is possible to add some I2C devices directly connected to your '''local''' GPIO into Domoticz.

Supported I2C devices are:
{| class="wikitable"
| - BMP085, BMP180
|Temp + Baro
|-
| - BMP280
|Temp + Humidity + Baro
|-
| - PCF8574, PCF8574A
|PIO 8 bit expander
|-
| - HTU21D
|Humidity + Temp
|-
| - TSL2561
|Illuminance
|-
| - MCP23017
|GPIO 16bit expander
|}

==Installation==
First connect the I2C device to the RPi GPIO Header.

Goto menu Setup - Hardware

*Type: Select ''I2C Sensors'' Hardware Gateway from the pull down list.
*Enabled/Disabled: you can disable the hardware gateway. The created devices stay active (but greyed out) but will not be updated.
*Name: Enter a meaningful name for this I2C Gateway
*Select Log Levels:
**Info: Shows info logging about the hardware and its devices in the log file or log page. This will normally generate the most log lines
**Status: Shows Status logging in the log file or log page.
**Error: Shows Error logging in the log file or log page.
*Data Timeout: Enable Data Timeout if needed (1 minute to 24 hours). Domoticz will restart the Hardware thread/plugin if after the set timeout still no data is received by the gateway.
*Select the I2C Subtype from the pulldown list
*Set the path to the I2C bus (eg /dev/i2c-1 or leave empty for autodetection)
*For expanders enter I2C address
*For expanders enable GPIO inversion if needed.

Click on Add to create the hardware. The related devices based on the I2C Subtype will be created and appear in the [[Setup Devices|device list]] (menu Setup - Devices) and in your Device tabs.


[[File:I2C-hardware.png]]

==Not supported I2C devices==
For not supported devices you could create an external script (python/bash) that will read/write with the I2C device. Create [[Dummy for virtual Switches|Dummy Virtual devices]] and with [[Domoticz API/JSON URL's|http URL/API commands]] update the domoticz devices.

For Python you need to install the smbus library

<code>sudo apt-get install python-smbus</code>

See also for example:

https://www.domoticz.com/forum/viewtopic.php?t=33516