Protocol: LC default communication rate: 9600Bps; LC Communication Protocol: Data (1) Starting identifier (default: 0xA0) Data (2) Switch address code (default: 0x01, identified as the first switch) Data (3) Operation data (0x00 is "OFF", 0x01 is "ON") Data (4) Check code Example: TURN ON: A0 01 01 A2 TURN OFF: A0 01 00 A1 HOW TO USE: 1. Plug the USB relay into the computer, install the CH340 serial port chip driver; 2. Open STC-ISP, SSCOM32, or other serial debugging software, set the baud rate to 9600, and send "A0 01 01 A2" in hexadecimal format to turn on the relay; send "A0 01 00 A1" in hexadecimal format to turn off the relay; USB intelligent control switch. Onboard high-performance controller chip. Board features CH340 USB controller chip. Onboard power LED and relay status LED. Onboard 5V, 10A / 250VAC, 10A / 30VDC relay, with long relay life of up to 100,000 cycles. Relay module includes overcurrent protection and freewheeling diode protection. Color: Blue Material: PCB Size: 49.6 x 16mm Package Contents: 1 x USB relay module Note: Light and display differences may cause slight color variation between the product image and actual item. Measurement error allowed is +/- 1-3cm.