Node-RED and the PI-SPI-DIN-RTC-RS485-4AI-4KO-8DI

Node-Red Requirements

Official Raspberry Pi OS Versions supported by Widgetlords Electronics:

Node-Red Version 1.x
NodeJS Version 10

Latest Node-Red release as per Node-Red site is Version 2.0 and not supported as yet by the Raspberry Pi OS

If this version is downloaded and installed, it defaults to NodeJS Version 14 which has a known bug which will cause system crashes when using the libwidgetlords libraries.

If using the Node-Red Version 2, NodeJS Version 12 must be installed instead of the default Version 14 or higher. This is not supported by Widgetlords Electronics.

Widgetlords Electronics will update the libwidgetlords libraries as soon as the Raspberry Pi OS supports the latest versions of Node-Red and NodeJS.

The PI-SPI-DIN-RTC-RS485-4AI-4KO-8DI series of modules now have Node-RED support for the main modules and PI-SPI-DIN expansion modules:

PI-SPI-DIN-8AI Analog Input
PI-SPI-DIN-4AO Analog Output
PI-SPI-DIN-8DI Digital Input
PI-SPI-DIN-4KO Relay Output

To use Node-RED with the PI-SPI-DIN-RTC-RS485-4AI-4KO-8DI series, please follow these instructions:

1. Install the Widgetlords libwidgetlords libraries as outlined in:

Getting Started with PI-SPI Libraries

2. In the /boot/config.txt file, make sure the line

dtoverlay=vpe-3011b

is present and comment out other widgetlords dtoverlay statements

3. Install npm. This can be done from a terminal by running:

sudo apt install npm

4. Start Node-RED from

RasPiMenu -> Programming -> Node-RED

5. Open a web browser on the RPi and go to

http://localhost:1880

6. Click on the hamburger menu in the top-right and then select

Manage Pallette

7. On the install tab search for:

widgetlords

8. Install the

node-red-contrib-widgetlords

package.

Once successfully installed, the Widgetlords Nodes should be available!

Here is a typical window showing a sample Flow using the PI-SPI-DIN-RTC-RS485-4AI-4KO-8DI series (VPE-3011B)