/*
 * Author: Mihai Tudor Panu <mihai.tudor.panu@intel.com>
 * Copyright (c) 2016 Intel Corporation.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/* This example demonstrates how to use one the ADS1015 ADC on the Grove Joule
 * Shield or the Sparkfun ADC Block for Edison with devices that output a small
 * differential voltage (e.g. geophones, piezoelectric bands or pads,
 * thermocouples).
 */
var mraa = require('mraa'); // Not used directly but required if jsupm_ads1x15 was installed from NPM
var upm = require('jsupm_ads1x15');
var fs = require('fs'); // Values will be written to a file
var file = "./ads1015.data" // Output filename
var id = 0; // Sample number
var ival; // Interval function for sampling

// Initialize and configure the ADS1015
var ads1015 = new upm.ADS1015(0, 0x48);

// Put the ADC into differential mode for pins A0 and A1
ads1015.getSample(upm.ADS1X15_MUX_DIFF_0_1);

// Set the gain based on expected VIN range to -/+ 2.048 V
// Can be adjusted based on application to as low as -/+ 0.256 V, see API
// documentation for details
ads1015.setGain(upm.ADS1X15.GAIN_TWO);

// Set the sample rate to 3300 samples per second (max) and turn on continuous
// sampling
ads1015.setSPS(upm.ADS1015.SPS_3300);
ads1015.setContinuous(true);

// Open the output file and start reading data once open
// Will overwrite file if it already exists
var stream = fs.createWriteStream(file);
stream.once('open', function() {
    ival = setInterval(function() {
        // Write data pairs of ID + Value for easy plotting
        stream.write(id + " " + ads1015.getLastSample().toFixed(7) + "\n");
        id++;
    }, 1); // Wait 1 ms between reads, (actuall call adds another ~1 ms overhead)
});

// Stop after 10 seconds and close the file
setTimeout(function() {
    clearInterval(ival);
    stream.end();
    console.log("Wrote " + id + " samples to file: " + file);
}, 10000);