Node RED data processing II

Overview

• This lesson will demonstrate how Node-Red can be used to process data from a sensor.
• In this lesson we will learn how to process the output from a python file using the function node in Node-RED.

Learning Objectives

• Learn how to run a Python program using the Terminal.
• Learn how to run a Python program using the Execute node in Node-RED.
• Learn how to extract data using the Function node in Node-RED.

learning to process data using Node-RED

• Node-RED makes it very easy to display data using a Dashboard, but first we need to get the data we need.
• Luckily, we have experience retrieving data from sensors using Python.
• Reading and processing data using Node-RED is not very different.

Open the file peter_hopper_get_data5.py

• From the main Raspberry Pi menu navigate to Programming and open Python3 IDLE.
• Navigate to the /home/pi/peter-hopper-t3 directory. (t3 is short for term 3).
• Open up the file peter_hopper_get_data5.py and review to make sure it is the same as the code below.

• Run the file and check that it can retrieve sensor data and send the standard output to the Python Shell.