node-red-contrib-pi-plates 0.4.0
control Pi-Plates boards from Node-RED
node-red-contrib-pi-plates
A Node-RED node that enables communication with Pi-Plates boards.
- RELAYplate
- RELAYplate2
- DAQCplate
- DAQC2plate
- TINKERplate
- MOTORplate
- ADCplate
- CURRENTplate
- DIGIplate
Prerequisites
You will need the python3-venv package. This is included by default in Raspberry Pi OS 'Bookworm' but not in previous releases.
sudo apt install python3-venv
Also, the SPI interface must be enabled. This is done using the 'sudo raspi-config' command under 'Interface Options' -> 'SPI'
Install
As of the 0.3.0 release, this package utilizes it's own python virtual environment that contains the pi-plates python package. This is automatically initialized when this package is installed, so it is no longer necessary to manually download and install the python pi-plates package.
Run the following command in your Node-RED user directory - typically ~/.node-red
npm install node-red-contrib-pi-plates
Upgrading from 0.3.0 to 0.4.0
Existing flows work without changes: node types and settings are the same. Upgrade with:
npm install [email protected]
This also installs pi-plates 0.4.0, which it requires. Then restart Node-RED.
What behaves differently:
- Failed commands raise errors. If a command fails, the node shows a red "command failed" status and raises an error that Catch nodes receive. In 0.3.0 the message was silently lost, and if the python co-process crashed every node went silent until Node-RED was restarted.
- Recovery is automatic. If the python co-process crashes it restarts by itself, and nodes carry on once it is back.
- "plate not ready" status. Messages that arrive before a plate has been verified, or while the co-process is restarting, are dropped with a yellow "plate not ready" status.
- LED node output. The LED node now outputs the new LED state (
1/0) in cases where 0.3.0 outputundefined, e.g. toggling a DAQC2plate LED.
Upgrade both packages together. node-red-contrib-pi-plates 0.3.0 accepts any
pi-plates version from 0.3.0 up, but it is not compatible with pi-plates 0.4.0: some
nodes can crash Node-RED when a command fails. If you need to stay on
node-red-contrib-pi-plates 0.3.0, pin pi-plates to 0.3.0 by adding this to the
package.json in your Node-RED user directory and running npm install there:
"overrides": {
"pi-plates": "0.3.0"
}
Usage
See built-in documentation for each node.
