accel-mma84
v0.2.4
Published
Library to run the MMA8452Q accelerometer.
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Readme
#Accelerometer Driver for the accel-mma84 Tessel accelerometer module. The hardware documentation for this module can be found here.
If you run into any issues you can ask for support on the Accelerometer Module Forums.
###Installation
npm install accel-mma84
###Example
/*********************************************
This basic accelerometer example logs a stream
of x, y, and z data from the accelerometer
*********************************************/
var tessel = require('tessel');
var accel = require('../').use(tessel.port['A']); // Replace '../' with 'accel-mma84' in your own code
// Initialize the accelerometer.
accel.on('ready', function () {
// Stream accelerometer data
accel.on('data', function (xyz) {
console.log('x:', xyz[0].toFixed(2),
'y:', xyz[1].toFixed(2),
'z:', xyz[2].toFixed(2));
});
});
accel.on('error', function(err){
console.log('Error:', err);
});
###Methods
# accel.availableOutputRates()
Logs the available interrupt rates in Hz.
# accel.availableScaleRanges()
Logs the available accelerometer ranges (in units of Gs).
# accel.enableDataInterrupts( trueOrFalse, callback(err) )
Enables or disables data interrupts, and thus, data
events. Set the first param truthy to enable, falsy to disable.
# accel.getAcceleration( callback(err, xyz) )
Gets the acceleration from the device, outputs as array [x, y, z].
# accel.setOutputRate( rateInHz, callback(err) )
Sets the output rate of the data (1.56-800 Hz).
# accel.setScaleRange( scaleRange, callback(err) )
Sets the accelerometer to read up to 2, 4, or 8 Gs of acceleration (smaller range = better precision).
###Events
# accel.on( 'data', callback(xyz) )
Emitted when data is available. xyz is an array in the form of [x, y, z].
# accel.on( 'error', callback(err) )
Emitted upon error.
# accel.on( 'ready', callback() )
Emitted upon first successful communication between the Tessel and the module.
###Further Examples
- Change Rates. This more advanced accelerometer example logs a stream of x, y, and z data, then stops the stream, changes the polling rate, and resumes streaming from the accelerometer.
- Show Axes. Demonstrates axes by turning on a different LED per axis (x, y, z) only when that axis has positive acceleration. Also prints +/- per axis to the console.
###Licensing
MIT or Apache 2.0, at your option