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overhang.stl

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    • hello.BLE-blink.C3.html 3.32 KiB 
    <!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<script>
//
// hello.BLE-blink.C3.html
//    Seeed XIAO ESP32C3 BLE blink hello-world
//    requires Chrome/Chromium/Edge
//       with Experimental Web Platform features enabled
//
// Neil Gershenfeld 11/13/23
//
// based on https://github.com/makerdiary/web-device-cli
//
const ServiceUUID = '6e400001-b5a3-f393-e0a9-e50e24dcca9e'
const RxUUID  = '6e400002-b5a3-f393-e0a9-e50e24dcca9e'
const TxUUID  = '6e400003-b5a3-f393-e0a9-e50e24dcca9e'
const MTU = 20
//
var bleDevice
var nusService
var rxCharacteristic
//
function message(msg) {
   document.getElementById("message").innerHTML = msg
   }
function connect() {
    if (!navigator.bluetooth) {
       message('Bluetooth not available, enable Experimental Web Platform features browser flag')
       return
       }
    navigator.bluetooth.requestDevice({
       optionalServices:[ServiceUUID],acceptAllDevices:true})
    .then(device => {
       bleDevice = device 
       message('connecting to '+device.name)
       bleDevice.addEventListener('gattserverdisconnected', ondisconnect)
       return device.gatt.connect()
       })
    .then(server => {
       return server.getPrimaryService(ServiceUUID)})
    .then(service => {
       nusService = service;
       return nusService.getCharacteristic(RxUUID)})
    .then(characteristic => {
       rxCharacteristic = characteristic
       return nusService.getCharacteristic(TxUUID)})
    .then(characteristic => {
       let txCharacteristic = characteristic
       txCharacteristic.startNotifications()
       txCharacteristic.addEventListener('characteristicvaluechanged',receive)
       message(bleDevice.name+' connected')})
    .catch(error => {
       message(''+error);
       if(bleDevice && bleDevice.gatt.connected) {
          bleDevice.gatt.disconnect()
          }
       })
   }
function disconnect() {
   if (!bleDevice) {
      message('nothing connected')
      return
      }
   if (bleDevice.gatt.connected)
      bleDevice.gatt.disconnect()
   else
      message('already disconnected')
   }
    function ondisconnect() {
   message(bleDevice.name+' disconnected')
   }
function receive(event) {
   let value = event.target.value
   let str = '';
   for (let i = 0; i < value.byteLength; i++)
      str += String.fromCharCode(value.getUint8(i))
   message('received: '+str)
   }
function transmit(s) {
    if(bleDevice && bleDevice.gatt.connected) {
       message("sent: "+s)
       let arr = new Uint8Array(s.length)
       for (let i = 0; i < s.length; i++) {
          let val = s[i].charCodeAt(0)
          arr[i] = val
          }
       send(arr)
       }
    else
       message('not connected')
   }
function send(a) {
   let chunk = a.slice(0,MTU)
   rxCharacteristic.writeValue(chunk)
   .then(function() {
      if (a.length > MTU) {
         send(a.slice(MTU))
         }
      })
   }
function LEDon() {
   transmit('1')
   }
function LEDoff() {
   transmit('0')
   }
</script>
</head>
<body>
<br>
<button onclick="connect()" style="margin-left:2%;font-size:150%">Connect</button>&nbsp;
<button onclick="disconnect()" style="font-size:150%">Disconnect</button>&nbsp;
<button onclick="LEDon()" style="font-size:150%">turn LED on</button>&nbsp;
<button onclick="LEDoff()" style="font-size:150%">turn LED off</button>&nbsp;
<br><br>
<div id='message' style="margin-left:2%"></div>
</body>
</html>