Cayenne PCF8574 Plugin

A plugin allowing the Cayenne Pi Agent to to read data from and write data to a PCF8574/PCF8574A device and display it in the Cayenne Dashboard.

Requirements

Hardware

• Rasberry Pi.
• PCF8574.

Software

• Cayenne Pi Agent. This can be installed from the Cayenne Dashboard.
• Git.

Getting Started

1. Installation

From the command line run the following commands to install this plugin.

cd /etc/myDevices/plugins
sudo git clone https://github.com/myDevicesIoT/cayenne-plugin-pcf8574.git

2. Modifying the plugin

Specify the device you are using by setting the class value under the PCF8574 section in the cayenne_pcf8574.plugin file. By default this is set to PCF8574 but it can also be set PCF8574A.

By default the plugin alternates between input and output channels. To specify different functions for specific channels you can modify the class for that section to specify DigitalInput or DigitalOutput.

3. Restarting the agent

Restart the agent so it can load the plugin.

sudo service myDevices restart

Temporary widgets for the plugin should now show up in the Cayenne Dashboard. You can make them permanent by clicking the plus sign.

NOTE: If the temporary widgets do not show up try refreshing the Cayenne Dashboard or restarting the agent again using sudo service myDevices restart.