Puck.js stuck while uploading code with noble.js

I'm on Raspbian Stretch,
Here the code from my app :

if (puckJSnoble) {
      puckJSnoble.connect()
      puckJSnoble.once('connect', () => {
        puckJSnoble.discoverAllServicesAndCharacteristics(function (
          error,
          services,
          characteristics
        ) {
          var txCharacteristic = findByUUID(characteristics, NORDIC_TX)
          var rxCharacteristic = findByUUID(characteristics, NORDIC_RX)
          console.log("passage connected");
          if (txCharacteristic && rxCharacteristic) {
            rxCharacteristic.subscribe(function () {
              try {
                var writeData = () => {
                  splitTheScript(scriptInit)
                  setTimeout(() => {
                    txCharacteristic.write(
                      stringToBuffer(splittedScript),
                      false,
                      function (error) {
                        if (error) {
                          console.log(
                            'error writing data in puck - init : ',
                            error
                          )
                        }
                        if (splitFinished == true) {
                          rxCharacteristic.unsubscribe(error => {
                            // console.log('unsubscribe : ', error)
                            puckJSnoble.disconnect(error => {
                              console.log(error)
                            })
                          })
                          splitFinished = false
                        } else {
                          writeData()
                        }
                      }
                    )
                  }, delayWrite)
                }
                if (!reseted) {
                  txCharacteristic.write(
                    stringToBuffer('reset()\nsave()'),
                    false,
                    function (error) {
                      puckJSnoble.disconnect(error => {
                        console.log(error)
                      })

                    }
                  )
                } else {
                  writeData();
                }
              } catch (e) {
                console.log('BT> SEND ERROR ' + e)
              }
            })
          }
        })
      })
      puckJSnoble.once('disconnect', () => {
        console.log('PASSAGE disconnect')
        if (reseted) {
          noble.startScanning([], true)
        } else {
          reseted = true;
          initPuck();
          cbStopScanning();
        }
      })
    }

// Converts a string to a Buffer
function stringToBuffer(str) {
  // console.log(str);
  var buf = new Buffer(str.length)
  for (var i = 0; i < buf.length; i++) {
    buf.writeUInt8(str.charCodeAt(i), i)
  }
  console.log('buffer : ', buf)
  return buf
}

// split the script every 19 byte (device's limit..)  to write data in puck.js
function splitTheScript(data) {
  var writeData = [{
    data: data,
    blockSize: 19
  }]

  var d
  var split = writeData[0].nextSplit || {
    start: 0,
    end: writeData[0].data.length,
    delay: 0
  }
  // Otherwise split based on block size
  if (split.end >= writeData[0].blockSize) {
    split = {
      start: 0,
      end: writeData[0].blockSize,
      delay: 0
    }
  } else {
    splitFinished = true
  }

  // Only send some of the data
  if (writeData[0].data.length > split.end) {
    if (split.delay == 0) split.delay = 50
    d = writeData[0].data.substr(0, split.end)
    writeData[0].data = writeData[0].data.substr(split.end)
    if (writeData[0].nextSplit) {
      writeData[0].nextSplit.start -= split.end
      writeData[0].nextSplit.end -= split.end
      if (writeData[0].nextSplit.end <= 0) writeData[0].nextSplit = undefined
    }
  } else {
    d = writeData[0].data
    writeData[0].data = ''
    writeData[0].nextSplit = undefined
  }
  // actually write data
  scriptInit = writeData[0].data
  splittedScript = d
  delayWrite = split.delay
  console.log(
    'Sending block ' + JSON.stringify(d) + ', wait ' + split.delay + 'ms'
  )
}