First, make sure the computer detects the serial port. If the door isn't there, choosing a Bootloader in Arduino IDE won't solve the problem.

What to check out

• Use verified data USB-cable and direct USB-computer connection. The charge cable can power the LED without transmitting data.
• In the device manager, monitor which device appears when fitted. Find the CH340 driver from the WCH manufacturer or as instructed by the panel supplier.
• For classic Nano with ATmega328P, select the appropriate panel, processor and COM-gate. If loading fails, check that execution requires ATmega328P (Old Bootloader).
• Close other programs using the same door. Complete the first test with a basic example and without an external circuit on RX/TX.

A Practical Example

If COM-the door appears and disappears along with the tile USB-part at least partially detected. Then discuss the correct error message when loading instead of simultaneously changing driver, panel and entire application.

Common error

Double RESET pressure is not a general procedure for all Nano plates. Classic AVR Nano and newer Nano families have different methods of loading.

For further reading

• Arduino: choice of processor and bootloader for Nano (English). Explanation of options ATmega328P, Old Bootloader and ATmega168 in Arduino IDE.

Compatibility check products

Select products according to the above criteria; the list is not a confirmation that they are all interchangeable.

• Arduino nano clone with USB C connector CH340
• Nano CH340 AtMega328 Development Panel