Description:

If you need to control power via your computer’s USB port, this is the right one to choose. This module has a CH340 USB to serial interface chip, and a STM8S103 MCU as a gateway to receive command and then control the relay to turn on and off. The relay module (SRD-05VDC-SL-C) can load up to 10A 250VAC power with no issue, that is enough for most of the applications.

Install the CH340 driver, write a few lines of codes, then developers can control a relay module. There are two LED indicators, one is for USB port connection and one is for relay on and off status.

Commands: 

• Turn On: A0 01 01 A2
• Turn Off: A0 01 00 A1

import serial

import time

usb_relay = serial.Serial("COM17",9600)

if usb_relay.is_open:

   print(usb_relay)

   on_cmd = b'\xA0\x01\x01\xa2'

   off_cmd =  b'\xA0\x01\x00\xa1'

   usb_relay.write(on_cmd )

   time.sleep(1)

   usb_relay.write(off_cmd)

   time.sleep(1)

usb_relay.close()


Specifications:

• Baud Rate: 9600BPS
• Relay Lifetime: 100K times
• Relay Contact Rating : AC 250V 10A, DC 30V 10A
• Dimensions: 63 x 16.3 x 19.2mm
• Weight: 15g

Links:

• CH340 
• Datasheet