A very small size USB to TTL serial module, the module uses Micro-USB interface, compatible with data cable, the module width and data cable plug width, directly inserted in the data line Micro-USB plug to use, very small and convenient. Compared to the use of A-type USB male connector directly plugged into the PC on the USB to TTL module, this module to connect the development board and other serial devices more convenient. Module based on CH340C chip, and CH340G, CH340T chip drive exactly the same. Module can be used to STC microcontroller and other support serial download program microcontroller download program, or as a PC and microcontroller serial communication line, stable and reliable. 1) driver IC CH340 is a USB bus adapter chip, to achieve USB to serial or USB to print port. CH340 built-in transceiver buffer, support for simplex, half duplex or full duplex asynchronous serial communication. The serial data includes one low-level start bit, 5, 6, 7 or 8 data bits, one or two high-level stop bits, and supports odd parity / even parity / flag check / blank Test. CH340 support common communication baud rate: 50,75,100,110,134.5,150,300,600,900,1200,1800,2400,3600,4800,9600,14400,19200,28800,33600,38400,56000, ; / & gt; and & ; ID = 0.0 & gt; 2) Development board power supply The following are the same as the " CH340 chip supports 5V supply voltage or 3.3V supply voltage. When using 5V operating voltage, CH340 chip VCC pin input 5V power supply, and V3 pin should be an external capacity of 0.1uF power decoupling capacitor. When using 3.3V operating voltage, CH340 chip V3 pin should be connected with the VCC pin, while the external input 3.3V power supply, and with the CH340 chip connected to other circuits can not exceed the operating voltage of 3.3V. Module defaults to 5V operating voltage, the chip voltagefrom the USB interface, if you want to change to 3.3V operating voltage, you need to back the module 5V, 3.3V working voltage selection point to switch to the middle point and another point shorted. At this point need to VCC feet to the module input 3.3V power supply, the module can work. Product Features 1) Chip: CH340C 2) Operating voltage: 5V or 3.3V 3) Data bits: 5bit, 6Bit, 7bit, 8bit 4) stop bits: 1,2 5) Verification: odd, even, no, Mark, space 6) Transmission rate: 50 ~ 2MHz 7) Current limiting fuse: 500ma 8) : Windows xp, win7,8,10 9) Operating temperature: -40 ~ 85 10) Size: 10.4mmx28.5mm The appearance and color of different batches of products may be different, which will not affect the use. Color: green Material: PCB Package Contents: 5 x Module With Cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.