This is the command to control 4-RELAYS Heavy Duty Stackable Card for Raspberry Pi
Don't forget to enable I2C communication:
~$ sudo raspi-config
~$ git clone https://github.com/SequentMicrosystems/4relay-rpi.git
~$ cd 4relay-rpi/
~/4relay-rpi$ sudo make install
Now you can access all the functions of the relays board through the command "4relay". Use -h option for help:
~$ 4relay -h
If you clone the repository any update can be made with the following commands:
~$ cd 4relay-rpi/
~/4relay-rpi$ git pull
~/4relay-rpi$ sudo make install
Python driver can be found here.
Node-Red example basd on "exec" node here.
Node-Red "4relay" node under construction.