NodeRed Flow for Controlling DockerPi 4-Channel Relay Module
https://wiki.52pi.com/index.php/DockerPi_4_Channel_Relay_SKU:_EP-0099
i2c controls for the DockerPi 4-Channel Relay Hat
Includes manual injects for on/off of each relay, master on/off injects, and link-in options for triggering these from other flows.
Simple install - just copy/paste JSON into NodeRed.