Universal CH340 download circuit

 
1. Use CH340N-SOP8, which has a smaller package and saves space.
2. A self-restoring fuse is added to the board. It will cut off the power when connected reversely (the effect has not been tested)
. 3. Four indicator lights are added to facilitate observation of the status. Four The indicator lights are USB powered, VCC powered, TXD, RXD
4, using TYPE-C, sunken board 0.8mm package. It is recommended to choose 1.6mm thickness or 1.2mm thickness for PCB. The TYPE-C port will be a little higher than the PCB board height.
5. Most of the chip components are on the front of the board and can be directly teppanyaki. Only one resistor is on the back.
6. Added STC microcontroller cold start switch for cold start downloading. This switch is a commonly used patch toggle switch. To be honest, I am not very satisfied. It is too high.
7. There is no large capacitor at TYPE-C. If your microcontroller circuit has a large load, it is recommended to add a large capacitor at TYPE-C.
 
Some people have questions, why not build an automatic cold start circuit? Do you have to manually cut off the power every time you download?
It doesn't exist. I have been playing with STC microcontrollers for 4 years and have downloaded it 1.7W times.
STC microcontroller does not have to power off to download programs.
My usual method is to enter the program into the ISP for downloading. If there is a problem with the program code,
you can press the reset button and enter the ISP for downloading. If the above two methods fail,
I will choose to power off . download. In fact, the number of downloads I use during power outages is relatively small. When adjusting the code, I don’t have the patience to manually cut off the power again and again.
Automatically download code sharing through programs:
MCU automatically downloads code (applicable to STC8-STC15)_bilibili_bilibili
[Code sharing] 51 microcontroller automatically downloads, bid farewell to manual power outage_bilibili_bilibili
STC microcontroller download ( Circuit) Solution Summary_bilibili_bilibili
The above content is all shared before, and a summary and comparison will be made later.