Search results for:

I have a similar question:

• Is it possible to require pressing the button to complete pairing? I don't want anyone in the world to be able to pair with my puck. Or is there some other BLE solution to preventing anonymous pairing access?
  

I couldn't get either the DS2xxx module or the code examples in this thread to work for writing to a DS2431, so I ended up porting some Java code I found to JavaScript and writing worked

https://gist.github.com/maxogden/c0b33da285e0fe809a8aa7009bc510f7

// Used with GeekHeart https://www.tindie.com/products/MakersBox/geekheart/

var ow = new OneWire(4) // D2 on NodeMCU
var code = ow.search()[0] // will be empty array if it failed to find your DS2431

// write a Uint8Array of arbitrary length 8 bytes at a time with a 100ms delay (add callback if you need it)
function write (data) {
  var buf = new Uint8Array(13)
  var row = 0
  
  function next () {
    var pos = row * 8;
    for (var i = 0; i < 8; i++) {
      buf[i] = data[pos + i]
    }
    write8(pos, buf);
    if (pos + 8 >= data.length) return console.log('done');
    row++;
    if (row >= 16) return console.log('done'); // EEPROM has 16 rows of 8 bytes
    setTimeout(next, 100);
  }
  
  next()
}

// write 8 bytes to addr offset
// example write8(0, new Uint8Array([1,1,1,1,1,1,1,1)
function write8 (addr, data) {
  console.log(addr, data)
  var i
  ow.reset();
  ow.select(code);
  ow.write(0x0F, 1);  // Write ScratchPad
  ow.write(addr, 1); 
  ow.write(0x00, 1); 
  for ( i = 0; i < 8; i++)
    ow.write(data[i], 1);  
  
  ow.reset();
  ow.select(code);    
  ow.write(0xAA);         // Read Scratchpad
  
  for ( i = 0; i < 13; i++)     
    data[i] = ow.read();

  ow.reset();
  ow.select(code);
  ow.write(0x55, 1);     // Copy ScratchPad
  ow.write(data[0], 1); 
  ow.write(data[1], 1);  // Send TA1 TA2 and ES for copy authorization
  ow.write(data[2], 1);
}

// read num bytes from addr offset
// example read(0, 8)
function read(addr, num) {
  ow.reset();
  ow.select(code);
  ow.write(0xF0); // read
  ow.write(addr&0xFF);
  ow.write(addr>>16);
  var buf = new Uint8Array(num)
  for (var i = 0; i < num; i++) buf[i] = ow.read()
  return buf
}

// same as read() but decodes into string
function readString (addr, num) {
  var buf = read(addr, num)
  var str = ''
  for (var i = 0; i < buf.length; i++) {
    str += String.fromCharCode(buf[i])
  }
  return str
}

// write a long string starting at addr 0
function writeString (str) {
  var data = new Uint8Array(str.split('').map(function (c){ return c.charCodeAt(0) }))
  write(data)
}