CH340 controller, providing for /Linux/for 32/64 bit drivers, native serial program does not require any modification. high-speed optocoupler with good waveform and a maximum speed of 921600bps (8 times 115200). Complete electrical isolation (including power and GND), 1500V withstand voltage, fully ensuring computer and personal safety. There is no electrical connection between the USB and serial ports, fully ensuring that the computer not be damaged due to external short circuits, impacts, etc., and not crash due to strong pulses or interference. PCB slotting, isolation spacing of 3mm or more, ensuring sufficient distance to avoid creepage. Prompt: This module can support simultaneous switching of signal and power pins to 5V/3.3V (using VCC for external power supply, with the same signal and VCC levels), as well as different levels of signal and power (using 5V or 3.3V pins for external power supply). Note: due to different production batches, the color of wire is random, and the designation is not accepted, which not affect the use. Pin function: The pins that must be connected for normal communication: Level selection pin: used to select the signal and power VCC pin level, must be connected to one of 5V or 3.3V. TX: Serial data transmission pin (referring to the module's own data outflow ,corresponding to the external device's RX. data reception). RX: Serial data receiving pin (referring to the module's own data input ,corresponding to the external device's TX data transmission) GND: Power Ground (GND must be connected and must not be connected incorrectly,otherwise it may damage the device or serial module) The following pins are not necessary for communication, please decide whether to connect them according to your own needs VCC: Power output (voltage determined by level selection jumper cap, maximum load should not exceed 150mA, recommended below 100mA) TX-D: The TX signal output through the reverse diode, . the open drain TX signal, can only output a low level and requires external pull-up. When downloading programs for microcontrollers, use TX-D instead of TX and connect it to the P30 pin of the MCU. 5V: 5V power output (from USB, maximum load should not exceed 150mA,recommended below 100mA) 3.3V: 3.3V power output(from ,maximum load should not exceed 150mA,recommended below 100mA) Color: Material:PCB Package Contents: 1 * Optical isolation USB to TTL serial port 1 * Line 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.