Problem with 8mhz pro mini board 3.3v

When compiling for a Arduino Pro Mini 8Mhz, 3.3v I set the serial baud to 9600, but the only way I can use the serial monitor is when I set it to 19200. This seems to also affect SPI bus frequencies. The same code compiled with the Arduino EDI works as expected. I have tried it on 2 different machines and have the same issue. Anyone knows how to solve this?

platform = atmelavr
board = pro8MHzatmega328
framework = arduino

Are you 100% sure that the crystall installed on the board reads 8.000 MHz and not 16 MHz? Can you show the exact Arduino IDE settings with which you’re compiling for?

The platformio.ini is correct, the pro8MHzatmega328 board has as definition 8MHz.

Though somehwere still there seems to be a factor 2 lost / added somewhere.

Hi Maxgerhardt,

Crystal is too small to identify. But the strange thing is that when I compile using the Arduino EDI the problem does not exist, so the crystal issue would be the same for both platforms. I will be receiving some brand new boards today, so I will solder some headers on it and give it test.

Greetz, Tiebolt

If the board has an external crystal, it is a 16 MHz board is most cases. 8 MHz can be achieved with internal clock only.

Hi Manuelbl,
I will wait for the new boards to arrive. They for sure are 8Mhz, 3.3V. The board I am using now is a Deek-Robot clone marked 3.3V and 8Mhz. But after your contribution I start doubting the correctness of these markings.
Greetz, Tiebolt

Hi All,

Just got my new boards and the problem is gone. Maybe I should not buy the cheap Chinese crap boards anymore ;). Sorry for any inconvenience and thanks for your support!
Case Closed.