Serial port circuit module-WeChat public account electronic chip

 
1. Introduction to
the serial port circuit module CH340 series (CH340C and CH340G). CH340C/CH340G data manual analysis, circuit design analysis, and completed the schematic diagram and PCB drawing of the serial port circuit. The difference between CH340G and CH340C is explained, mainly in pins 7 and 8 of the chip. CH340G requires a 12MHz crystal oscillator and starting capacitor at pins 7 and 8, while CH340C has a built-in crystal oscillator in the chip, so there is no need to connect it. However, after comparing the cost difference between CH340G and CH340C, the cost difference is less than 2 cents, so you can see which one you need to choose based on the cost to design the serial port circuit, which is more convenient. Note: In the design, the USB type A female socket and the type-c interface are reused at the same time, so that when welding, you can choose the USB type A female socket interface or the type-c interface according to your needs, which is more convenient.
2.
The first lesson of the video tutorial: Data manual analysis schematic PCB
live playback: https://www.bilibili.com/video/BV1q64y1c7QD/
The second lesson: Physical welding debugging
 
51 microcontroller download program, Bluetooth applet communication test
live playback ：https://www.bilibili.com/video/BV11v411C7yR/
3. Schematic diagram PCB picture
4. Physical diagram and test
PCB physical diagram
module Physical diagram
module Power on the physical diagram
module to download the program to the 51 microcontroller Physical test diagram
module and Bluetooth The module is connected to transmit data to the computer, and the WeChat applet on the mobile phone is connected to Bluetooth to transmit data in both directions.