1，How to flash bootloaser firmware into ESP32 with Flash_download_tool?
We can flash bootoader and firmware.bin into ESP32 with PlatformIO,but it is not convenient, one reason is that it will take a long time since it will build the source code before burn every time.
Here we use the Flash_download_tool which save me a lot of time in some case.
The partions.bin and firmware.bin are in your build folder,while you can download the bootloader_dio_40m.bin , boot_app0.bin and tool.exe from our github here.
2, How to flash firmware into STM32 pandapiV2.9
Here I just talk about PandapiV2.9,The tutorial is Here . Beside that tutorial we can use any other tool like secureCRT to download firmware,since the bootloader use the Ymodem protocol to receive firmware.bin from serial port.
3，How to flash firmware into AVR chip, ATmega2560 1284P which used on arduino board and many 3D printer board.
We normally flash the firmware with arudion IDE,but the same problem is that it is not convenient.and Then I find there is a simple tool for that. you can download this tool from our github here
just run the tool with command like:
avrdude -c wiring -P COM7 -b115200 -p atmega2560 -D -U flash:w:firmware_printer.hex:i
open the cmd.exe and goto the avrdude.exe folder, run that command, be sure the hex file in the same folder