https://github.com/hoegaarden/sensor-am2302

node.js module to read data from an am2303 (and others) temperature/humidity sensor
https://github.com/hoegaarden/sensor-am2302

Last synced: 12 days ago
JSON representation

node.js module to read data from an am2303 (and others) temperature/humidity sensor

• Host: GitHub
• URL: https://github.com/hoegaarden/sensor-am2302
• Owner: hoegaarden
• Created: 2013-03-03T22:13:33.000Z (almost 12 years ago)
• Default Branch: master
• Last Pushed: 2013-03-03T22:18:45.000Z (almost 12 years ago)
• Last Synced: 2023-04-09T12:18:23.717Z (over 1 year ago)
• Language: JavaScript
• Size: 117 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

README

        
# sensor-am2302

## About

This is a small module to read data from a AM2302 (and others) Temp/Hum-Sensor.

For reading data, it spawns a binary (stolen from [Adafruit]) and parsing its output.

This module comes with a precompiled binary for RaspberryPi.

## Usage

    var Sensor = require("sensor-am2303")

      , temp_hum = new Sensor({pin:17})

    ;

    temp_hum.read(function(err, data) {

        if (err) {

            console.error(err);

        } else {

            console.log("Temp: ", data.temp);

            console.log("Hum:  ", data.hum);

        }

    });

## Functions / Methods

### Constructor

The constructor can take an object with configuration data. The defaults are:

    var defaults = {

        bin  : path.join(__dirname, '..', 'bin', 'Adafruit_DHT')

      , args : [ '2302' ]

      , pin  : 17

      , temp : /Temp\s*=\s*([-+]?[0-9]*\.?[0-9]+)/

      , hum  : /Hum\s*=\s*([-+]?[0-9]*\.?[0-9]+)/

      , sudo : true

    };

    

 - `bin` is the path to the binary which gets called to read the sensor data

 - `args` holds additional arguments with which the `bin` gets called.

 - `pin` is the GPIO pin to which the sensor is connected - actually this gets passed to `bin` as the last argument

 - `temp` & `hum` are regular expressions with parse the STDOUT of `bin` to extract the meassured values

 - `sudo` should `bin` get executed via sudo?

### read(cb)

This method spanws teh binary, reads its output and extracts the meassured data. You can pass a callback function which takes two arguments `error` and `data`.

#### `error`

    null

or

    { code: 1, stdout: 'some string', stderr: 'some other string' }

`code` is the return code of the binary and `stdout`/`stderr` is the data the binary wrote to SDTOUT/STDERR.

    

#### `data`

    { temp: 23.1, hum: 50 }

`temp` is the current tempeature in degrees celsius and `hum` is the humidity in percent.

## Events 

This module is derived from `EventEmitter` and therefore exposes followig events:

### Event `stdout`

The binary wrote something to STDOUT. The data it wrote gets passed as an argument.

### Event `stderr`

Same as `stdout`, but for STDERR.

### Event `temp`

The module could parse the temprature. The temperature gets passed as argument.

### Event `hum`

Same as `temp`

### Event `data`

Bot the temperature and humidity were read. Both get passed in an object like [the data object](#data-object) for the callback for the `read()`-method.

### Event `error`

Some error occured. An object like [the error object](#error-object) gets passed.

### Event `done`

Everything is done, the reading of the sensor is finished. This Event gets emitted even when there were errors. It doesn't pass any arguments.

  [adafruit]: https://github.com/adafruit/Adafruit-Raspberry-Pi-Python-Code/tree/master/Adafruit_DHT_Driver