A Node-RED node to read from the Adafruit MAX31865 board, which can be connected to the PT100 and PT1000 Resistance Temperature Detectors (RTDs).
The node will appear as MAX38165 Converter in the menu, listed in the Raspberry Pi category.
- Ensure to enable SPI on your Raspberry Pi:
- Run
sudo raspi-config - Select
5 - Interfacing Options - Select
P4 - SPI - Select
yesto enable SPI - Select
OKto confirm - Select the
Finishbutton
- Wire the board as described in the Adafruit article for the Python Computer Wiring:
- Pi 3V3 to sensor VIN
- Pi GND to sensor GND
- Pi SPI0 MOSI to sensor SDI
- Pi SPI0 MISO to sensor SDO
- Pi SPI0 SCLK to sensor CLK
- Pi SPI0 CE0 to sensor CS
If you would like to connect multiple MAX31865's to a single Raspberry Pi, have them share the MOSI, MISO and SCLK pins. Then assign the first board the CE0 pin and the second board the CE1 pin.
More details on the Raspberry Pi pinout: https://pinout.xyz/pinout/spi
Run the following command in your Node-RED user directory - typically ~/.node-red
npm install node-red-contrib-pi-max31865
Find the node MAX38165 Converter in the menu and add it to your workflow. The configuration speaks for itself:
- bus - first digit in /dev/spidev0.0
- device - second digit in /dev/spidev0.0
- nominal resistance of sensor
- reference resistance on board
- wires used for sensor (2, 3 or 4)
- name to set a custom name
Connect a debug node to quickly assess that everything is working. The output will appear in the debug panel. Use a timestamp inject node as input to trigger readings on a regular interval. Use node-red-dashboard nodes for visualization, i.e. use ui_chart to plot data points on a graph.