hardware

The sos.hardware API groups together methods for working with hardware. It allows opening serial ports, using bar scanner or controlling LEDs.

warning

• Before using this API, ensure that the display supports serial via sos.display.supports("SERIAL").
• Samsung Kiosk serial connection only works over serial ports, not over USB ports.

Device Hardware Capabilities

| Capability | Description | |:------------|:-------------| | `SERIAL` | If the device supports sending and receiving data via serial ports |

	If you want to check if the device supports this capability, use [`sos.display.supports()`](https://developers.signageos.io/sdk/sos/display#supports).

List of supported serial ports

Bellow is example list of serial ports that can be used with sos.hardware.openSerialPort() method.

Device type	Default value	Other available values
RaspberryPi / Linux	/dev/ttyS0	/dev/ttyS1, /dev/ttyUSB0, /dev/ttyUSB1
Windows	COM3	COM1, COM2, COM4 etc. Usually it's always COM3
Samsung Kiosk	PORT1	PORT2, PORT3, PORT4
Android	/dev/ttyusb0	/dev/ttyusb1, /dev/ttyusb2
BrightSign	0	0 (Serial Jack as /dev/ttyS0), 1 (GPIO port as /dev/ttyS1), USB:A/0 (USB-to-serial as /dev/ttyUSB0)

Methods

openSerialPort()

The openSerialPort() method opens a serial port for reading/writing. After the port is opened the method returns

openSerialPort(options: ISerialPortOptions): Promise<ISerialPort>;

Params

Name	Type	Required	Description
options.device	string | undefined	No	Specifies the address of the external device, check the table above for ports.
options.baudRate	number	Yes	Specifies the data transmission speed in bits per second.
options.parity	Parity | undefined	No	Specifies the form of error checking, whether (or what) extra bits are added to a byte.
options.databits	number | undefined	No	Specifies the number of bits in a byte.
options.stopbits	number | undefined	No	Specifies the number of bits used to signal the end of a communication packet.
options.rtscts	boolean | undefined	No	Enables or disables RTS/CTS handshaking over the serial port. Currently supported by selected models of BrightSign.

Return value

Returns a promise that resolves to an instance of

Possible errors

• If the serial port cannot be opened.
• If the device address is not supported by the platform.
• If the device fails to process the data.
• If any other error occurs while opening the serial port.

Example

// Open serial port on BrightSign with default settings
const serialPort = await sos.hardware.openSerialPort({
	device: '0',
	baudRate: 9600,
});
serialPort.write('68656c6c6f'); // Write "hello" in hexadecimal

API Example

import { sos } from '@signageos/front-applet';

void sos.onReady(async () => {
	// Open default serial port based platform
	const serialPort = await sos.hardware.openSerialPort({
		baudRate: 115200,
	});

	await serialPort.close();
});

void sos.onReady(async () => {
	// Open specific serial port
	const serialPort = await sos.hardware.openSerialPort({
		device: '/dev/ttyUSB0',
		baudRate: 115200,
	});

	serialPort.onData((data) => {
		const dataString = [...data].map((char) => String.fromCharCode(char)).join('');
		console.log(dataString);
	});

	await serialPort.write('68656c6c6f'); // hexadecimal string
	await serialPort.write([10, 20, 30, 40]); // array of numbers
	await serialPort.write(Uint8Array.from([10, 20, 30, 40])); // Uint8Array

	await serialPort.close();
});