Serial

A serial library written in TypeScript for Deno without any third party modules.

This library provides an interface for the communication with serial devices and doesn’t use any third party modules. It uses C++ functions which are included in a dynamic link library or shared object. These functions are then loaded by deno to establish a serial connection and talk to the devices.

This library and the documentation are still work in progress!

Features

• Communication with serial devices.
• Create multiple serial connections at the same time.
• List available ports and their properties.
• Set timeouts for both reading and writing.
• All functions are async (currently not implemented yet).
• Uses no third party modules.
• Works on different operating systems (check compatibility for mor info).

Compatibility

Examples - How to use

To use this library you need the following flags to run it:

• --unstable
• --allow-ffi

Ports

Get a list with all serial ports and their info that are currently available on your system.

main.ts

import { Serial } from "./mod.ts";

// create new instance of a serial object
const serial = new Serial();

// get all available ports
const availablePorts = serial.getPortsInfo();

// console log the list
console.log(availablePorts);

Example output:

[
  { name: 'COM1' },
  { name: 'COM2' },
  ...
  { name: 'tty/USB1' }
]

Sending

Send data to a serial device. For exampe to an Arduino.

main.ts

import { Serial, baudrate } from "./mod.ts";

// create new instance of a serial object
const serial = new Serial();

// open the connection
serial.open('COM1', baudrate.B9600);

// encode the message to a Uint8Array
const textToSend = 'Hello from TypeScript!';
const encodedTextToSend = new TextEncoder().encode(textToSend);

// send the message
serial.send(encodedTextToSend, encodedTextToSend.length);

Reading

Read data from a serial device. Again, in our example from an Arduino.

Depending on your Arduino board you may need to press the reset button on the board after uploading the sketch, in order to receive data.

sketch.ino

void setup() {
  Serial.begin(9600);
  while (!Serial) {
    ;
  }
}

void loop() {
  Serial.println("Hello from Arduino!");
}

main.ts

import { Serial, baudrate } from "./mod.ts";

// create new instance of a serial object
const serial = new Serial();

// open the connection
serial.open('COM1', baudrate.B9600);

// create a new buffer to store incoming bytes,
// in this example we want to read a maximum of 100 bytes
const bufferToRead = new Uint8Array(100);

// read data into the buffer
serial.read(bufferToRead, bufferToRead.length);

// decode the data from the buffer
const decodedTextToRead = new TextDecoder().decode(bufferToRead);

// console log the text
console.log(decodedTextToRead);

Example output:

Hello from Arduino!

WIP

import { Serial, baudrate } from "./mod.ts";

const serial = new Serial();

const availablePorts = serial.getAvailablePorts()

console.log('serial properties (available ports):', availablePorts);

console.log('serial properties (isOpen):', serial.isOpen);

console.log('serial.open():', serial.open(availablePorts[1].name, baudrate.B9600));

const textToSend = 'Hello World!'
const dataToSend = new TextEncoder().encode(textToSend);

console.log('serial.write():', serial.write(dataToSend, dataToSend.length, 10, 10));

console.log('writing:', textToSend);

const dataToRead = new Uint8Array(20);

console.log('serial.read()', serial.read(dataToRead, dataToRead.length, 10, 10));

console.log('reading:', new TextDecoder().decode(dataToRead));

console.log('serial.close()', serial.close());

Arduino:

char incomingBytes[10];

int charsRead = 0;

void setup() {
  Serial.begin(9600);
  while (!Serial) {
    ;
  }
}

void loop() {
  int available = Serial.available();
  if (available > 0) {
    charsRead = Serial.readBytes(incomingBytes, available);

    Serial.print(incomingBytes);
  }
}

Credits

• Big thanks goes out to @Katze719 who wrote most of the C++ files and functions!
• Thanks to @AapoAlas for the great support and help on the Deno Discord!

Licence

Apache-2.0. Check LICENSE for more details. Feel free to contribute to this project.

Copyright 2023 © Max