Incorrect reading from serial port

[julietafoglia]

SerialPort Version

13.0.0

Node Version

v22.13.0

Platform

Windows 11

Architecture

x64

Context

Trying to read data server side in a web app (NextJS) from a Scale connected via USB (USB-to-serial port).
Read on XXX seconds intervals.

Code example

const port = new SerialPort({
      path: "COM3",
      baudRate: 1200,
      autoOpen: false,
      dataBits: 8,
      stopBits: 1,
      parity: "none"
    });
 
    return new Promise((resolve, reject) => {
      port.open((err) => {
        if (err) {
          reject(new NextResponse(JSON.stringify({ error: err.message }), { status: 500 }));
        }
      });
     
 
      port.on("data", (data) => {
        const weight = data.toString();
        resolve(new NextResponse(JSON.stringify({ weight }), { status: 200 }));
        port.close();
      });
    });
  } catch (error) {
...
  }

Results

Weight reading is not correct. For instance, for an object weighing 1.28 kg, it reads a combination of those numbers repeated several times with some 0 an Ls in between:
LLLLLL00000000888888L2222200001LLLL0L...

Additional information

• Reading from Web serial API shows correct readings. For instance, for an object weighing 1.28 kg, it streams:
  L00128L00128L00128L00128L ....

• Using Hercules utility displays the same readings as Web serial API:
  L00128L00128L00128L00128L ....