CH340 controller, providing for Windows/Linux/for Mac 32/64 bit operating system drivers, native serial program does not require any modification. Imported 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 will not be due to external short circuits, impacts, etc., and will 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 will 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, i.