Espruino + Bluetooth Slack Bookmarklet!

Ever wanted to control your Espruinos from Slack? Now you can :)

• In Chrome, open 'Bookmrk manager'
  
• Go to 'Bookmarks bar', right-click and add bookmark
  

• Type 'slack-espruino' as the name, then paste the code below into the URL and save:

  javascript:(function() {
  var knownMessages = [];
  
  function write(str) {
  var u = new Uint8Array(str.length);
  for (var i=0;i<str.length;i++)
    u[i] = str.charCodeAt(i);
  console.log("Writing ",JSON.stringify(str));
  bluetoothTX.writeValue(u.buffer).then(function() {
    console.log("Written!");
  })
  }
  function poll() {
  var m = document.querySelectorAll(".c-message__message_blocks");
  for (var i=0;i<m.length;i++) {
    if (knownMessages.includes(m[i])) continue;
    knownMessages.push(m[i]);
    var msg = m[i].innerText.trim();
    console.log("New message:",msg);
    if (msg.startsWith("Espruino:"))
      write(msg.substr(9).trim()+"\n");      
  }
  }
  
  var bluetoothDevice, bluetoothServer, bluetoothTX;
  navigator.bluetooth.requestDevice({ filters: [{services: ["6e400001-b5a3-f393-e0a9-e50e24dcca9e"]},{namePrefix: "Puck"}]}).then(device => {
  console.log('Connecting to GATT Server...');
  bluetoothDevice = device;
  return device.gatt.connect();
  }).then(function(server) {
  console.log("Connected");
  bluetoothServer = server;
  return server.getPrimaryService("6e400001-b5a3-f393-e0a9-e50e24dcca9e");
  }).then(function(service) {
  return service.getCharacteristic("6e400002-b5a3-f393-e0a9-e50e24dcca9e");
  }).then(function(char) {
  bluetoothTX = char;
  console.log("Completed!");
  setInterval(poll,1000);
  });
  })();
  

• Now open Slack for the web browser. This can be a pain on Android if you have the app installed, requiring you to view the sign-in page 'as desktop browser'

• Go to the specific chat you care about

• Open the slack-espruino bookmark you just made (or copy/paste the code above into the address bar)

• Choose an Espruino device in the bluetooth popup that appears

• Any message that anyone writes in the conversation that starts with Espruino: (has to be the same capitalisation) will be sent to Espruino. For example: Espruino:LED.set() will turn the LED on!

That is cool. I see you got inspired by @benjaminbenben micro chat post.

That's cool stuff.

Out of curiosity, would that also work with other types of chat or websites, or is there something Slack-specific in that code?

would that also work with other types of chat or websites

Yes, it'd work with pretty much anything! About the only requirement is the website uses HTTPS (not HTTP)