Recently, I’ve been learning embedded development with STM32. However, since I don’t have STLINK, I have to use CH340 for flashing. Here’s a quick overview of the process.

Required Software

• Keil5
• FlyMcu

Steps

• CH340 Pinout:

  • VCC: Jumper cap for setting 5V/3.3V
  • RX: Connects to GPIO PA09 for receiving
  • TX: Connects to GPIO PA10 for transmitting
  • GND: Ground connection

• For flashing, a hex file is needed. So, in my IDE Keil5, additional settings are required.

  • Click the magic wand icon (options for target).
  • Output > create hex file.
  • After building, the hex file will appear in the Objects folder.

• The flashing software used here is FlyMcu. Below are the flashing steps:

  • Plug in CH340 and ensure that the COM port above is for our CH340.
  • Code file for online ISP > Choose the built hex file.
  • Check Verify, Run After ISP complete.
  • Uncheck Program OptionBytes when ISP.
  • Click Start ISP.

• If the message on the right side shows the following, it indicates success:

  1 2 3

  .... Write 1KB Ok,100%,@1562ms Go from 08000000 Ok

• If you want to flash a new program, press the reset button on the STM32.