RPICT and Node Red hosted on Raspberrypi

Make sure any program using the ttyAMA0 serial is off (emonhub, python programs etc).

We assume a fresh install of Raspberry Pi OS in this document.

Make sure the steps to setup the serial port have been completed first.
Howto setup Raspbian for serial read

Install Node-Red as follow

sudo apt-get install nodered

Start Node Red


You will see a similar message to this below at the top

Once Node-RED has started, point a browser at <>

Open a browser and go the indicated address. for us here.

How to setup Node-Red depends on what the user wants to achieve. We will show a simple example here to split the data from the serial string.

Start to build a flow with a Serial Input a Function block and Debug output.


Now setup the serial port as shown below:


Then enter the java script in the function. Make 3 outputs are selected. Modify the script to your needs. We will just provide NodeID the First Real Power and Vrms from a RPICT7V1.


The code is here below for copy paste.

var output = msg.payload.split(" ");

var NodeID = parseInt(output[0]);
var RP1    = parseFloat(output[1]);
var Vrms   = parseFloat(output[15]);

var msg1 = {payload : NodeID};
var msg2 = {payload : RP1};
var msg3 = {payload : Vrms};

return [msg1, msg2, msg3];

The right pane debug will show the split values.