ADS1115 analog gain signal module - how to run it with espruino?

I still use 1v81 , now used this code

    var CONFIG = {
    OS_MASK      : (0x8000),
    OS_SINGLE    : (0x8000),  // Write: Set to start a single-conversion
    OS_BUSY      : (0x0000),  // Read: Bit = 0 when conversion is in progress
    OS_NOTBUSY   : (0x8000),  // Read: Bit = 1 when device is not performing a conversion
                
    MUX_MASK     : (0x7000),
    MUX_DIFF_0_1 : (0x0000),  // Differential P = AIN0, N = AIN1 (default)
    MUX_DIFF_0_3 : (0x1000),  // Differential P = AIN0, N = AIN3
    MUX_DIFF_1_3 : (0x2000),  // Differential P = AIN1, N = AIN3
    MUX_DIFF_2_3 : (0x3000),  // Differential P = AIN2, N = AIN3
    MUX_SINGLE_0 : (0x4000),  // Single-ended AIN0
    MUX_SINGLE_1 : (0x5000),  // Single-ended AIN1
    MUX_SINGLE_2 : (0x6000),  // Single-ended AIN2
    MUX_SINGLE_3 : (0x7000),  // Single-ended AIN3
                
    PGA_MASK     : (0x0E00),
    PGA_6_144V   : (0x0000),  // +/-6.144V range = Gain 2/3
    PGA_4_096V   : (0x0200),  // +/-4.096V range = Gain 1
    PGA_2_048V   : (0x0400),  // +/-2.048V range = Gain 2 (default)
    PGA_1_024V   : (0x0600),  // +/-1.024V range = Gain 4
    PGA_0_512V   : (0x0800),  // +/-0.512V range = Gain 8
    PGA_0_256V   : (0x0A00),  // +/-0.256V range = Gain 16
                
    MODE_MASK    : (0x0100),
    MODE_CONTIN  : (0x0000),  // Continuous conversion mode
    MODE_SINGLE  : (0x0100),  // Power-down single-shot mode (default)
              
    DR_MASK      : (0x00E0),  
    DR_128SPS    : (0x0000),  // 128 samples per second
    DR_250SPS    : (0x0020),  // 250 samples per second
    DR_490SPS    : (0x0040),  // 490 samples per second
    DR_920SPS    : (0x0060),  // 920 samples per second
    DR_1600SPS   : (0x0080),  // 1600 samples per second (default)
    DR_2400SPS   : (0x00A0),  // 2400 samples per second
    DR_3300SPS   : (0x00C0),  // 3300 samples per second
             
    CMODE_MASK   : (0x0010),
    CMODE_TRAD   : (0x0000),  // Traditional comparator with hysteresis (default)
    CMODE_WINDOW : (0x0010),  // Window comparator
              
    CPOL_MASK    : (0x0008),
    CPOL_ACTVLOW : (0x0000),  // ALERT/RDY pin is low when active (default)
    CPOL_ACTVHI  : (0x0008),  // ALERT/RDY pin is high when active
            
    CLAT_MASK    : (0x0004),  // Determines if ALERT/RDY pin latches once asserted
    CLAT_NONLAT  : (0x0000),  // Non-latching comparator (default)
    CLAT_LATCH   : (0x0004),  // Latching comparator
               
    CQUE_MASK    : (0x0003),
    CQUE_1CONV   : (0x0000),  // Assert ALERT/RDY after one conversions
    CQUE_2CONV   : (0x0001),  // Assert ALERT/RDY after two conversions
    CQUE_4CONV   : (0x0002),  // Assert ALERT/RDY after four conversions
    CQUE_NONE    : (0x0003),  // Disable the comparator and put ALERT/RDY in high state (default)
    };
    var GAINS = {
      6144 : CONFIG.PGA_6_144V,  // +/-6.144V range = Gain 2/3
      4096 : CONFIG.PGA_4_096V,  // +/-4.096V range = Gain 1
      2048 : CONFIG.PGA_2_048V,  // +/-2.048V range = Gain 2 (default)
      1024 : CONFIG.PGA_1_024V,  // +/-1.024V range = Gain 4
      512 : CONFIG.PGA_0_512V,  // +/-0.512V range = Gain 8
      256 : CONFIG.PGA_0_256V,  // +/-0.256V range = Gain 16;
    };
    var REG = {
      MASK : 3,
      CONVERT : 0,
      CONFIG : 1,
      LOWTHRESH : 2,
      HITHRESH : 3
    };
    function ADS1X15(i2c) {
      this.i2c = i2c;
      this.addr = 0x48;
      this.gain = 0;
    }
    ADS1X15.prototype.writeRegister = function(reg, value) {
      this.i2c.writeTo(this.addr, reg, value>>8, value);  
    };
    ADS1X15.prototype.readRegister = function(reg) {
      this.i2c.writeTo(this.addr, reg);  
      var d = this.i2c.readFrom(this.addr, 2);
      return (d[0] << 8) | d[1];  
    };
    /// set the gain, with a value in mv (6144, 4096, 2048, 1024, 512 or 256). The value is the full swing, so 256 = +/- 0.256v
    ADS1X15.prototype.setGain = function(gain) {
      if (!(gain in GAINS)) throw new Error("Gain "+gain+" not found");
      this.gain = gain;
    };
    ADS1X15.prototype.getADC = function(channel, callback) {
      var config = CONFIG.CQUE_NONE    | // Disable the comparator (default val)
                        CONFIG.CLAT_NONLAT  | // Non-latching (default val)
                        CONFIG.CPOL_ACTVLOW | // Alert/Rdy active low   (default val)
                        CONFIG.CMODE_TRAD   | // Traditional comparator (default val)
                        CONFIG.DR_1600SPS   | // 1600 samples per second (default)
                        CONFIG.MODE_SINGLE;   // Single-shot mode (default)
      // Set PGA/voltage range
      config |= this.gain;
      // Set single-ended input channel
      config |= [CONFIG.MUX_SINGLE_0,CONFIG.MUX_SINGLE_1,CONFIG.MUX_SINGLE_2,CONFIG.MUX_SINGLE_3][channel];
      // Set 'start single-conversion' bit
      config |= CONFIG.OS_SINGLE;
      // Write config register to the ADC
      this.writeRegister(REG.CONFIG, config);
      // Wait for the conversion to complete
      var ads = this;
      setTimeout(function() {
        // Read the conversion results
        // Shift 12-bit results right 4 bits for the ADS1015
        callback(ads.readRegister(REG.CONVERT)); 
      }, 8);
    };
    // then try with
    I2C1.setup({ scl : B6, sda: B7} );
    var ads = new ADS1X15(I2C1);
      ads.setGain(512); // +/- 0.256mV


    function everySecond() {
     ads.getADC(0, function(val0) {
      ads.getADC(1, function(val1) {
       ads.getADC(2, function(val2) {
        ads.getADC(3, function(val3) {
         console.log(val0,val1,val2,val3);
        });
       });
      });
     });
    }
    setInterval(everySecond, 1000);

and ADS shows me only one channel value, I've connected 3 voltage sources into it,

|_____|___|  _|_| |___|_|_|_|___|
          |_| http://espruino.com
 1v81 Copyright 2015 G.Williams
>echo(0);
=undefined
4531 75 79 78
4533 74 79 78
4580 75 79 77
4527 75 78 78
4622 75 79 78

I checked 3 other ADS, they are working on arduino, but here I get only one value,
could anyone help to fix it? please

also I am not sure about gain settings,
seems they have some error too, as eg. 256 gain shows lower value than 2048?