Node-RED node to get temperature in centigrades from DS18B20 sensors
It is compatible only with RaspberryPi hardware and it only reads the temperature values from sensors. The base library is a npm module, which handles with the whole 1-Wire protocol with DS18B20 sensors (aka it does the magic).
- NPM site: https://www.npmjs.com/package/node-red-contrib-sensor-ds18b20
- Historic downloads statistics: https://npm-stat.com/charts.html?package=node-red-contrib-sensor-ds18b20&from=2017-01-23&to=2022-01-23
Physical Connection of sensor(s)
The DS18B20 sensors must be connected on GPIO4 (or physical pin #7) because this is the only pin that supports native 1-Wire protocol. The scheme of connection is typically the one on the image below.
On the Linux system where your Node-RED is running and where your sensors are connected to, make sure you have loaded all the kernel modules needed for working with 1-Wire devices, what the DS1820 sensor is. Thus, you need to active or have activated the 1-Wire Interface on the Rpi. To do this just go to the Raspi-Configuration page with:
Interfaces and then to
enable it and reboot the device. You are done.
Run the following command in the root directory of your Node-RED install
npm install node-red-contrib-sensor-ds18b20
Or just use the
package manager(or manage pallette) from the Node-Red Interface to search for this module and install it manually.
- You can select a 1-wire device/sensor from a dropdown list in the configuration dialog of the node
- Configurable time interval of the sensor sampling (in seconds)
- Periodic sensor sampling can be disabled, and sample temperature only when an external message arrives.