maxogden

Most recent activity

• Some Puck questions

  in Puck.js, Pixl.js and MDBT42 • 7 years, 11 months

  

  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?
    
• DS24B33/DS2431 eeprom

  in Interfacing • 8 years, 3 months

  

  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)
  }