Rotary encoder and digital potentiometer

I got past the 8-bits vs 16-bits issue and I was just listening to my first song on the si4703; Phil Collings I believe...

	/*
		si4703 begins reading from register upper register of 0x0A and reads 
		to 0x0F, then loops to 0x00. Since register 0x0A comes in first 
		we have to shuffle the array around a bit.
	*/

	si4703.prototype.readReg = function ( verb ) {
		//this.i2c.writeTo( this.addr, 0 );
		data = this.i2c.readFrom( this.addr, 32 );

		for( var i=0; i<data.length; i+=2 )
		{
			bits = data [ i ] << 8;
			bits |= data[ i+1 ];

			reg = ( i < 12 ? i+(10-i/2) : (i/2)-6 );
			this.registers[reg] = bits;
		}

		if( verb !== false )
			this.printReg();
	};

	/*
		Write the current 9 control registers (0x02 to 0x07) to the Si4703. 
		It's a little weird, you don't write an I2C addres, The Si4703 assumes 
		you are writing to 0x02 first, then increments.
	*/
	si4703.prototype.writeReg = function () {
		bytes = [];
		for( i=0x02; i<0x08; i++ )
		{
			var high = this.registers[ i ] >> 8;
			var low  = this.registers[ i ] & 0x00FF;
			bytes.push(high, low);
		}
		this.i2c.writeTo( this.addr, bytes );
	};

	si4703.prototype.printReg = function () {
		console.log( 'Register    | Dec     | Hex    | Bits');
		fill   = String('.');

		for( var i in this.r )
		{
			label = i;
			dec = this.registers[ this.r[i] ];
			hex = dec.toString(16);
			bits = dec.toString(2);

			console.log( label + fill.repeat(10-label.length ) 		+ '  | ' +
						 dec   + fill.repeat(6-String(dec).length)  + '  | ' +
						 hex   + fill.repeat(5-hex.length)  		+ '  | ' + 
						 fill.repeat(18-bits.length) + bits
				);
		}
		console.log(" ");
	};

This is working just fine:

Register    | Dec     | Hex    | Bits
DEVIDEID..  | 4674..  | 1242.  | .....1001001000010
CHIPID....  | 2640..  | a50..  | ......101001010000
POWERCFG..  | 50433.  | c501.  | ..1100010100000001
CHANNEL...  | 0.....  | 0....  | .................0
SYSCONFIG1  | 6144..  | 1800.  | .....1100000000000
SYSCONFIG2  | 21....  | 15...  | .............10101
SYSCONFIG3  | 0.....  | 0....  | .................0
TEST1.....  | 48132.  | bc04.  | ..1011110000000100
TEST2.....  | 6.....  | 6....  | ...............110
BOOTCONFIG  | 1.....  | 1....  | .................1
STATUSRSSI  | 28693.  | 7015.  | ...111000000010101
READCHAN..  | 205...  | cd...  | ..........11001101
RDSA......  | 255...  | ff...  | ..........11111111
RDSB......  | 0.....  | 0....  | .................0
RDSC......  | 0.....  | 0....  | .................0
RDSD......  | 0.....  | 0....  | .................0

So now onwards to an Espruino-port of the Arduino sketch!