/* * Author: Mihai Tudor Panu * 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 of the ADS1115 ADCs on the * DFRobot Joule Shield 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 = "./ads1115.data" // Output filename var id = 0; // Sample number var ival; // Interval function for sampling // There are two ADS1115 chips on the DFRobot Joule Shield on the same I2C bus // - 0x48 gives access to pins A0 - A3 // - 0x49 gives access to pins A4 - A7 var ads1115 = new upm.ADS1115(0, 0x48); // Configure the ADS1115 for the SM-24 Geophone // Put the ADC into differential mode for pins A0 and A1, // the SM-24 Geophone is connected to these pins ads1115.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 ads1115.setGain(upm.ADS1X15.GAIN_TWO); // Set the sample rate to 860 samples per second (max) and turn on continuous // sampling ads1115.setSPS(upm.ADS1115.SPS_860); ads1115.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 + " " + ads1115.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);