I finally made them work
I was not using the right clock for programming, 16MHz instead of 8MHz...
Thanks @AWI

Hello,
I just got 2 boards and I'em trying to test them. For now I only plugged a usb/serial adapter with an ftdi to the JP3 connector to program the board. The program is simple as Serial.begin(9600); Serial.println("test");

But that's not working. The programming was done successfully, and when I open the Serial monitor in the arduino ide, all I got is garbage characters. I have setup the correct communication option in the ide of course. The power VCC comes from my USB and I tried with 3.3v or 5v, but it did not change anything.

When I do the with a standard arduino mini pro, it works correctly, but not with the @ceech boards...

Any idea why and whats wrong here?
thanks