uart.js connect directly to espruino?

[espruino-discuss2]

Posted at 2020-03-09 by Mrbbp

Hello,

i'm playing with the uart.js lib to connect an espruino to a webpage.
Is it possible to connect to an espruino by command line (js) without the menu "bt4 or webserial", if i know the name of my espruino?
and can i use connection.close() (line 3) to disconnect the espruino from the page (without closing the webpage)? (to update the code in the webIDE)

i use this example

let connection;
    if (connection) {
      connection.close();
      connection = undefined;
    }
    UART.connect((c) => {
      if (!c) {
        console.log("Pas de connexion");
        alert("Impossible de se connecter");
        return;
      }
      console.log("Connecté");
      connection = c;
      // Handle the data we get back, and call 'onLine'
      // whenever we get a line
      resultData = "";
      connection.on("data", (d) => {
        resultData = d;
        resultData  = resultData.replace(/\r\n|>|\[J/g, '');
        if (resultData.length > 1) {
          document.querySelector("article").innerHTML = resultData;
        }
      });
    });

regards

é.

[espruino-discuss2]

Posted at 2020-03-09 by Mrbbp

i tried connection.close() but received an error

Uncaught (in promise) TypeError: Failed to execute 'close' on 'SerialPort': Cannot cancel a locked stream
at Object.connection.close (uart.js:272)

how to unlockStream?

[gfwilliams]

Posted at 2020-03-10 by @gfwilliams

I'm not sure about Cannot cancel a locked stream - I haven't come across that one before :(

If you want to use the command-line and not the browser (eg Node.js) then there's https://serialport.io/ - not quite the same API but it's a very similar idea.

But from the Web Browser itself, for security they say that you have to bring up the port chooser at least once (but there's no need for the BT/USB menu).

UART.js is based on Web Serial, so you could use that directly and you'd have a lot more flexibility (and avoid having the menu) - check out https://codelabs.developers.google.com/codelabs/web-serial/#3

[espruino-discuss2]

Posted at 2020-03-10 by Mrbbp

Cannot cancel a locked stream

this is the error from the browser... sorry ;)
the page is connected to espruino
on the espruino:

const onInit  = () => {
  var step = 0;
  require("Encoder").connect(A8,A5, (dir) => {
    step += dir;
    print(step);
    if (dir > 0) {
      //allume la led 20ms
      digitalPulse(LED1, 1, 20);
    } else {
      digitalPulse(LED2, 1, 20);
    }
  });
};

i suppose the port is in use and therfor browser can not cancel connection...

thanks for your time.
é.

[gfwilliams]

Posted at 2020-03-11 by @gfwilliams

i suppose the port is in use

Could it be open in another browser window? sometimes you can do that with things like Web Bluetooth, and that might cause the error?