Sensor TSL2561 for node.js

A node.js module for working with the light sensor TSL2561 via i2c.

About the sensor

The TSL2561 is a light sensor who combines one broadband photodiode (visible plus infrared) and one infrared-responding photodiode. That means you can separately measure infrared, full-spectrum or human-visible light. A breakout with the sensor is available at adafruit or watterott (Germany). This driver/module based on the latest datasheet from ams. An older version is available at adafruit.

Install

$ npm install sensor_tsl2561

Raspberry PI

Enable i2c on your Pi if you haven't done already. To avoid having to run the i2c tools as root add the ‘pi’ user to the i2c group:

sudo adduser pi i2c

Usage

The module is easy to use. You have different config-options

Simple Usage

var TSL2561 = require('sensor_tsl2561');

var sense = new TSL2561();
sense.init(function(err, val) {
  if (!err) {
    sense.getLux(function(error, val) {
      if (!error) console.log(val + ' lux');
    });    
  }
});

Don't forget to call init()

ìnit() powers up the sensor and sets the given options.

Options

The default options are:

{
    'debug': false,
    'address': 0x39,
    'device': '/dev/i2c-1',
    'powerMode': 'powerUp',
    'timingMode': '402ms',
    'gainMode': '1',
    'packageType': 'auto',
}

Configure the sensor by supplying an options object to the constructor like:

var sense = new TSL2561({
    'timingMode': '13.7ms',
    'gainMode': '16'
});

packageType-Option

The sensor is available as package type "CS" or "T/FN/CL". The package types are using different lux calculation methods. You can set the package type as CS, T/FN/CL or auto. If auto is set, the value from ID-Register is used to get the sensors package type. For more details on this read the id section in the old and the new manual to see the differences.

Getter & Setter for sensor settings

Getter supports only callbacks. Setter supports callbacks and event-emitters - sensorSettingChanged and sensorSettingFailed. Getter and setter are:

getPowerMode(cB) / setPowerMode(newMode, [cB]) / modes: 'powerUp', 'powerDown'
getTimingMode(cB) / setTimingMode(newMode, [cB]) / modes: '13.7ms', '101ms', '402ms', 'n/a'
getGainMode(cB) / setGainMode(newMode, [cB]) / modes: '1', '16'

The sensorId is only a getter:

getSensorId(cB) / with 'TSL2560CS', 'TSL2561CS', 'TSL2560T/FN/CL', 'TSL2561T/FN/CL'

Light-Measurements

Measurement-functions using a callback and some of them an event-emitter. All events including a timestamp and additional data like the address to determine the sensor, who emitted the event.

getLight0([cB]) - channel 0 light value
getLight1([cB]) - channel 1 light value
getLux([cB]) - the calculated lux value (depends on channel 0 and 1) - emits event newSensorValue on success or sensorValueError on error
getAllValues([cB]) - all values (raw and calculated) - emits event newSensorValues on success or sensorValuesError on error

Tests

Because it's not really a good idea to run test in an unknown environment all tests under test using a faked devices and not really your i2c bus. The faked device using a faked i2c-bus which is realised with the proxyquire module.

To run the complete test suite nodeunit is required. The best way is using grunt and the shipped gruntfile which comes with this module.

Examples

All examples are using a real device on address 0x39 on your i2c bus. Be carefully if you have more as one device on your i2c or/and if you don't use the default address for the sensor.

Licence

The licence is GPL v3 and the module is available at Bitbucket and GitHub.

timelapseplus/tsl2561_node