DS24B33/DS2431 eeprom

Hi, I know @DrAzzy was going to look at this, but the bits arrived and I couldn't resist.

Note: you need a 0.2-2.2k pullup resistor - so pretty hefty (not like the ~10k you can get away with on the DS18B20).

var ow = new OneWire(B15);
var code = ow.search()[0];

function write(addr, data) {
  while (data.length>0) {
    var l = data.length;
    if (l>8) l=8; // 32 works with DS2433, but need 8 for DS2431
    ow.reset();
    ow.select(code);
    ow.write(0x0F); // write spad
    ow.write(addr&0xFF);
    ow.write(addr>>16);
    for (var i=0;i<l;i++) 
      ow.write(data.charCodeAt(i));

    ow.reset();
    ow.select(code);
    ow.write(0xAA); // read spad
    var a=[ow.read(),ow.read(),ow.read()];

    ow.reset();
    ow.select(code);
    ow.write(0x55); // copy spad to eeprom
    ow.write(a[0]);
    ow.write(a[1]);
    ow.write(a[2],true/*pull up for write*/);
    // TODO: maybe we should delay here?
    
    // get ready for next iteration, if there is one
    data=data.substr(l);
    addr+=l;
  }
}


function read(addr, cnt) {
  ow.reset();
  ow.select(code);
  ow.write(0xF0); // read
  ow.write(addr&0xFF);
  ow.write(addr>>16);
  var res = "";
  while (cnt--) res += String.fromCharCode(ow.read());
  return res;
}

write(0,"Hello World")
read(0,16)
// ="Hello World\x00\x00\x00\x00\x00"

I'll stick it in a module soon.