@growbox/sensors/src/converters/Mcp3008AnalogToDigitalConverter.js

An abstraction layer for a selection of raspberry-compatible sensors

/**
 * @author nstCactus
 * @date 09/12/2017 15:15
 */

const AbstractAnalogToDigitalConverter = require('./AbstractAnalogToDigitalConverter');
const Mcp3008                          = require('mcp3008.js');

const _devicePath = new WeakMap();
const _mcp3008    = new WeakMap();

class Mcp3008AnalogToDigitalConverter extends AbstractAnalogToDigitalConverter {
  constructor(name, uid, devicePath) {
    super(name, uid);

    _devicePath.set(this, devicePath);
    _mcp3008.set(this, new Mcp3008(devicePath));
  }

  /**
   * Read from the ADC to get the value of the sensor connected to `adcPin`
   * @param {number} adcPin The ADC pin to read from
   * @returns {Promise<number>} A promise that, when fulfilled, contains the value read from the sensor connected to `adcPin`
   */
  async read(adcPin) {
    return new Promise((resolve, reject) => {
      _mcp3008.get(this).read(adcPin, (err, value) => {
        if (err) {
          reject(err);
        } else {
          resolve(value);
        }
      });
    });
  }
}


module.exports = Mcp3008AnalogToDigitalConverter;