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().

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	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	No	Specifies the form of error checking, whether (or what) extra bits are added to a byte.
options.databits	number	No	Specifies the number of bits in a byte.
options.stopbits	number	No	Specifies the number of bits used to signal the end of a communication packet.
options.rtscts	boolean	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();
});