How to send data from python console to Node-Red on raspberry pi

General
1

Hello Guys,

I am reading the data of some temperature sensors using python on Raspberry pi. Now i want to send that data to node red application running on the same Raspberry pi. Does node-red has some built in node to receive this data on node-red?

How can i easily do it?

Thank you!

2

Depends - if it is a one time request then use the exec node to call your program - If it supplies data continuously then use the node-red-node-daemon node to call it.

3

I've found MQTT perfect for this. My Python code "publishes" the data and node-red "subscribes" and reads it with an MQTT input node. I usually use a local mosquitto "broker" running on the Pi to do this "interprocess communication".

4

Node-RED has lots of ways:

  • exec node
  • MQTT
  • TCP
  • UDP
  • HTTP
  • Websockets

For example, I use some BASH scripts that end with a call to a web page that Node-RED hosts with suitable data POSTed.

5

I use python scripts to send MQTT to MQTT Node Red all the time. Easy to do, and keeps loading on sending device light. I even have a python based systemd service that accepts MQTT directives from NR via MQTT and then return data via MQTT to NR. In my case, I use a dedicated MQTT broker, to keep broker loading off front end device, and off NR device as well.

6

This topic was automatically closed 60 days after the last reply. New replies are no longer allowed.