Connect over Serial

Serial (USB) is the default CONDUYT transport. No network, no broker, no configuration - just plug in and go.

Firmware

Flash this minimal sketch to your board:

#include <Conduyt.h>

// Both sides must use the same baud rate (default: 115200)
ConduytSerial transport(Serial, 115200);
ConduytDevice device("MyDevice", "1.0.0", transport);

void setup() {
  Serial.begin(115200);
  device.begin();
}

void loop() {
  device.poll();
}

Find your serial port

macOS

ls /dev/cu.usb*
# /dev/cu.usbmodem14101   ← typical Arduino
# /dev/cu.usbserial-0001  ← typical FTDI/CH340

Linux

ls /dev/ttyACM* /dev/ttyUSB* 2>/dev/null
# /dev/ttyACM0   ← typical Arduino with native USB
# /dev/ttyUSB0   ← typical FTDI/CH340 adapter

Windows

Open Device Manager → Ports (COM & LPT). You'll see entries like COM3 or COM4.

Or from PowerShell:

[System.IO.Ports.SerialPort]::GetPortNames()
# COM3
# COM4

If no port appears, try a different USB cable - some cables are charge-only and don't carry data.

JavaScript (Node.js)

Install the SDK:

npm install conduyt-js

Create connect.mjs:

// connect.mjs
import { ConduytDevice } from 'conduyt-js'
import { SerialTransport } from 'conduyt-js/transports/serial'

const transport = new SerialTransport({
  path: '<YOUR_PORT>',    // e.g. '/dev/cu.usbmodem14101' or 'COM3'
  baudRate: 115200
})

const device = await ConduytDevice.connect(transport)

console.log('Firmware:', device.capabilities.firmwareName)
console.log('Pins:', device.capabilities.pins.length)

// Toggle pin 13
await device.pin(13).mode('output')
await device.pin(13).write(1)
console.log('Pin 13 HIGH')

await device.disconnect()

node connect.mjs

Expected output:

Firmware: MyDevice
Pins: 20
Pin 13 HIGH

Browser (WebSerial)

WebSerial requires a Chromium browser (Chrome or Edge) and a user gesture - you must call connect() inside a click, keydown, or pointerdown event handler. Calling it on page load will fail silently.

<!-- index.html -->
<button id="connectBtn">Connect</button>
<pre id="log"></pre>

<script type="module">
  import { ConduytDevice } from 'conduyt-js'
  import { WebSerialTransport } from 'conduyt-js/transports/web-serial'

  document.getElementById('connectBtn').addEventListener('click', async () => {
    const transport = new WebSerialTransport({ baudRate: 115200 })
    const device = await ConduytDevice.connect(transport)
    // Browser opens a port picker - user selects their board

    document.getElementById('log').textContent =
      `Connected to: ${device.capabilities.firmwareName}\n` +
      `Pins: ${device.capabilities.pins.length}`

    await device.pin(13).mode('output')
    await device.pin(13).write(1)

    document.getElementById('log').textContent += '\nPin 13 HIGH'
  })
</script>

Python

Install the SDK with serial support:

pip install conduyt-py[serial]

Create connect.py:

# connect.py
import asyncio
from conduyt import ConduytDevice
from conduyt.transports.serial import SerialTransport


async def main():
    transport = SerialTransport('<YOUR_PORT>', baudrate=115200)
    device = ConduytDevice(transport)
    hello = await device.connect()

    print(f"Firmware: {hello.firmware_name}")
    print(f"Pins: {hello.pin_count}")

    await device.pin(13).mode("output")
    await device.pin(13).write(1)
    print("Pin 13 HIGH")

    await device.disconnect()


asyncio.run(main())

python connect.py

Go

go get github.com/virgilvox/conduyt/sdk/go
go get go.bug.org/serial

// main.go
package main

import (
    "context"
    "fmt"
    "log"
    "time"

    "go.bug.org/serial"
    conduyt "github.com/virgilvox/conduyt/sdk/go"
)

func main() {
    port, err := serial.Open("<YOUR_PORT>", &serial.Mode{BaudRate: 115200})
    if err != nil {
        log.Fatal("Failed to open port: ", err)
    }

    ctx := context.Background()
    transport := conduyt.NewSerialTransport(port)
    device := conduyt.NewDevice(transport, 5*time.Second)

    hello, err := device.Connect(ctx)
    if err != nil {
        log.Fatal("Connection failed: ", err)
    }
    fmt.Println("Firmware:", hello.FirmwareName)
    fmt.Println("Pins:", hello.PinCount)

    if err := device.Pin(13).Mode(ctx, conduyt.PinModeOutput); err != nil {
        log.Fatal(err)
    }
    if err := device.Pin(13).Write(ctx, 1); err != nil {
        log.Fatal(err)
    }
    fmt.Println("Pin 13 HIGH")

    device.Disconnect(ctx)
}

go run main.go

Troubleshooting

Permission denied (Linux)

Your user needs to be in the dialout group to access serial ports:

sudo usermod -aG dialout $USER
# You MUST log out and log back in for this to take effect

Port busy / "Resource busy"

Another process has the port open. Close any serial monitors (Arduino IDE Serial Monitor, screen, minicom, PlatformIO serial monitor) before connecting. Only one process can hold a serial port at a time.

No data / garbled output

The baud rate must match on both sides. If the firmware uses 115200 and the host uses 9600, you'll get silence or garbage. Double-check both.

Device not detected / no port in /dev

1. Try a different USB cable - charge-only cables don't carry data
2. Try a different USB port on your computer
3. On some boards (ESP32 with CH340 chip), you may need to install CH340 drivers