DS18B20 Onewire Temperature Sensor


Provides an interface for Dallas DS18B20 temperature sensors over the DS2482 onewire bridge

Install

$ npm install @jahartley/ds2482-temperature

Usage

const DS18B20 = require('@jahartley/ds2482-temperature');

const sense = new DS18B20();

sense.init()
.then(() => sense.search())
.then(() => sense.readTemperatures())

.then(temps => {
  console.log(temps); // Returns a list of temperature reading from all found sensors
})

.catch(err => {
  console.error(err);
});

Streaming

const DS18B20 = require('@jahartley/ds2482-temperature');

const sense = new DS18B20();

sense.init()

.then(() => {
  sense.on('data', val => {
    console.log(val);
  });

  sense.on('error', err => {
    console.error(err);
  });
});

API

new DS18B20([options])

Creates an interface for Dallas DS18B20 temperature sensors. The instance inherites from readable stream and will search and emit measurements for all found sensors when a data listener is added.

Options:

• wire an instance of wire
• i2c an instance of i2c
• address the i2c address of the bridge chip, default: 0x18
• device the location of the i2c interface, default: /dev/i2c-1
• units the temperature units, default: C
• pollRate the rate to poll the sensors when streaming, default: 30 secs

sense.init()

Resets the bridge chip and any onewire devices connected to it

Returns: Promise <Uint8> resolves with DS2482 status register

sense.search()

Searches the bus and returns a list of found temperature sensors

Returns: Promise <Array <Sensor>> resolves with list of sensors

[
  <Sensor "2826274402000012">,
  <Sensor "28493331020000bf">,
  <Sensor "280b135f020000d9">
]

sense.readTemperatures()

Initiates a measurement and returns the temperature readings from all known sensors

Returns: Promise <Array {rom:String, value:Number, units:Sting}> resolves with list of temperatures

[
  {rom: "2826274402000012", value: 22.9375, units: "C"},
  {rom: "28493331020000bf", value: 22.875, units: "C"},
  {rom: "280b135f020000d9", value: 21.9375, units: "C"},
]

sense.destroy()

Destroys the streaming interface

new DS18B20.Sensor(rom [, options])

Creates a temperature sensor instance. The instance inherites from readable stream and will emit measurements from the sensor when a data listener is added.

Arguments:

• rom the ROM address of the sensor as a 16 character hex encoded string

Options:

• wire an instance of wire
• i2c an instance of i2c
• address the i2c address of the bridge chip, default: 0x18
• device the location of the i2c interface, default: /dev/i2c-1
• units the temperature units, default: C
• pollRate the rate to poll the sensor when streaming, default: 30 secs

sensor.readTemperature()

Initiates a measurement and returns the temperature reading from a particular sensor

Returns: Promise <Number> resolves with temperature

22.9375

sensor.destroy()

Destroys the streaming interface