Reactive stream for the LSM303 I2C 3D compass and accelerometer module
MIT License
This is an npm module that creates Rx.JS streams of readings from the LSM303 I2C 3D compass and accelerometer module. Information on the LSM303DLHC can be found here and it is available for purchase at Adafruit.
var i2c = require("i2c-bus");
var Lsm303Driver = require("lsm303-rx").Lsm303Driver;
var options = {
// looking at the source code, the synchronous and
// asynchronous open functions are identical
i2c: i2c.openSync(1)
};
lsm303 = new Lsm303Driver(options);
console.log('Reading 10 headings...');
lsm303.streamHeadings(500) // sample every 500 ms
.take(10)
.subscribe(
function (heading) {
console.log('Next: ' + heading);
},
function (err) {
console.log('Error: ' + err);
},
function () {
console.log('Completed');
}
);
Note that you need to open the i2c-bus
and pass it in to the module.
i2c
(required): The object used to communicate to the PWM/servo driver.magOffset
: Offset to be applied to the magnometer readings.magMin
: Expected minimum values for the compass module. ThismagMax
to calculate an offset (by averaging themagOffset
is given.magMax
: Expected maximum values for the compass module. ThismagMin
to calculate an offset (by averaging themagOffset
is given.debug
: If truthy, debugging to the console will be enabled.streamHeadings(interval, forwardVector)
: Produces a stream of headings ininterval
: (optional) the polling interval in milliseconds for theforwardVector
(optional) the normalized vector that represents "forward" on the{ x: 1, y: 0, z: 0 }
.streamAccelerometer(interval)
: Produces a stream of 3D accelerometer data.
interval
: (optional) the polling interval in milliseconds for thestreamMagnometer(interval, rawData)
: Produces a stream of 3D magnometer data.
interval
: (optional) the polling interval in milliseconds for therawData
: (optional) if truthy, then the raw magnometer data is returnedfalse
.This project uses the debug
library for
debugging. This allows you to enable debugging using environment variables or in
code before constructing the Lsm303Driver
object. The name of the debugging
stream produced by the library is lsm303
.See the debug library documentation
for more information.
This project is written in TypeScript. The library can be used by plain JavaScript as shown above, and the typing information is also included with the library so that anyone wishing to use Typescript will gain the benefits of the type information.
This module was based on
Pololu's Arduino library for the LSM303 module
with some ideas borrowed from
the lsm303
NPM module.