ds18x20.js

A node.JS implementation for using the DS1820, DS18S20 and/or DS18B20 temperature sensor with Raspberry Pi.

Description

This package is to be used by Raspberry Pi installed with node.JS to interact with the awesome temperature sensors DS1820, DS18S20 and DS18B20 made by Maxim integrated.

At time of writing only the DS18B20 sensor have been tested out with this package. Please tell me if you get the chance to test it with the other sensors.

Installation

$ npm install ds18x20

Usage

Each function in this library can be used sync or async. The same functions are used. The only difference is that if the last argument have a callback function, then it's an async function. There will be examples below for each function, both as sync and async.

Declaring the sensor library

var sensor = require('ds18x20');

Check if driver is loaded

To be able to probe the sensors, the temperature driver needs to be loaded in your Raspberry pi (done with the command sudo modprobe w1-gpio && sudo modprobe w1-therm).

async

sensor.isDriverLoaded(function (err, isLoaded) {
    console.log(isLoaded);
});

sync

var isLoaded = sensor.isDriverLoaded();
console.log(isLoaded);

output

true / false

Load the driver

Should the driver not be loaded you can use the command below. However, to run this command you need to be root (sudo node). Instead of loading the driver through node, I recommend loading the driver at startup through shell script: sudo modprobe w1-gpio && sudo modprobe w1-therm.

async

sensor.loadDriver(function (err) {
    if (err) console.log('something went wrong loading the driver:', err)
    else console.log('driver is loaded');
});

sync

try {
    sensor.loadDriver();
    console.log('driver is loaded');
} catch (err) {
    console.log('something went wrong loading the driver:', err)
}

List all available sensors

async

sensor.list(function (err, listOfDeviceIds) {
    console.log(listOfDeviceIds);
});

sync

var listOfDeviceIds = sensor.list();
console.log(listOfDeviceIds);

output

[ '28-00000574c791', '28-00000574f4f3' ]

Get the temperature from all avaiable sensors

The temperature is requested from each sensor. The result is returned in Celsius degrees and rounded to in decimal place.

async

sensor.getAll(function (err, tempObj) {
    console.log(tempObj);
});

sync

var tempObj = sensor.getAll();
console.log(tempObj);

output

Temperature in x° C

{ '28-00000574c791': 22.9, '28-00000574f4f3': 22.8 }

Get the temperature from one or several sensors

The result is returned in Celsius degrees and rounded to in decimal place.

async

sensor.get('28-00000574c791', function (err, temp) {
    console.log(temp);
});

sync

var temp = sensor.get('28-00000574c791');
var listOfTemps = sensor.get(['28-00000574c791', '28-00000574f4f3']);
console.log(temp);
console.log(listOfTemps);

output

Temperature in x° C

23.1
[ 23.1, 23.2 ]