I ordered some Pro Minis however get some WAVGAT clone thingies. The first problem was it is running too slow (4x slower) when compiling with default "Pro or Pro Mini" board profile. Serial however works in this situation but at 2400 baud instead of 9600 baud (Serial was initialized with 9600 baud).

Then I download the board definitions for the WAVGAT clones and select "WAVGAT Pro Mini". After uploading the same code, the clockspeed looks okay however no serial output at all (tried every baud speed available at the serial monitor).

Any idea how to fix this?

Here is the sample code:

#include <Arduino.h>
void setup() 
  // put your setup code here, to run once:
  while( !Serial ) {}
  Serial.begin( 9600 );
  pinMode( 13, OUTPUT );

void blinkLed()
  digitalWrite( 13, HIGH );
  delay( 1000 );
  digitalWrite( 13, LOW );
  delay( 1000 );

void loop() {
  // put your main code here, to run repeatedly:
  Serial.println( "hello" );
  delay( 1000 );


The board I have has a WAVGAT AVGA328P MCU, which is actually a Light Green LGT8F328P MCU instead of a the original Atmel/Microchip ATMEGA328P. This MCU can run at max 32Mhz instead of max 16Mhz.

  • \$\begingroup\$ Why no datasheet link? \$\endgroup\$
    – Transistor
    Jan 30, 2020 at 18:37
  • \$\begingroup\$ Because I don't have/find one. \$\endgroup\$
    – Codebeat
    Jan 30, 2020 at 19:11
  • \$\begingroup\$ If you are happy with you 'fix', go to. However, I'd suggest that this is unnacceptable behaviour by the provider and many recipients will not be as capable as you and will be left with unusable devices. Or, if lucky, may find a solution after much effort. If enough documentation is not provided to make the devices work (and arguably, even then) the supplier has failed to meet a reasonable minimal standard. If you purchased via Aliexpress / Amazon / Banggood / ... you probably qualify for a full refund. Failure top exercise that right will leave others disadvantaged. || Would I? Don't know. \$\endgroup\$
    – Russell McMahon
    Jan 31, 2020 at 0:24
  • \$\begingroup\$ @RussellMcMahon You are right, it is insane. They were cheap and now I know why they were cheap. Look the same on the outside except some prints and.... the modelnumber on the MCU, I discovered later when I start to work with it and noticed the strange delay. I don't recommend to buy these because these are some sort of pinout compatible however not exactly the same and need other software to do the same (still I don't know if there are other compatibility issues). If you want a better MCU, you buy a better MCU, really don't understand why they designed these things, can be very confusing.... \$\endgroup\$
    – Codebeat
    Jan 31, 2020 at 1:05
  • \$\begingroup\$ Ordered these a few months ago, refund impossible I guess. Can do two things, throw these away or try to find a solution. Hopefully the answer I found can help others. Time will tell if these are of any use. \$\endgroup\$
    – Codebeat
    Jan 31, 2020 at 1:05

1 Answer 1


Okay, that was pretty fast. Something wrong with the board definitions/library? dunno.

There are several implementations of the board definitions/library available and some are old or incomplete (?).

This version works and give you also some nice features as setting the clock speed and internal/external crystal etc. Take a look at: https://github.com/dbuezas/lgt8fx

This one also works: https://github.com/LGTMCU/Larduino_HSP

I have installed both and now the serial problem seems to be solved. Additional info (of Ralph Bacon) can be found here: https://github.com/RalphBacon/LGT8F328P-Arduino-Clone-Chip-ATMega328P

Warning: However, I still don't know how stable these more feature rich clones are and how compatible these are with the Atmel/Microchip ATMEGA328P MCU. Time will tell, when I find some issues, I will update this answer.

Hopefully this info can help others too.


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