I built an diy arduino using a max232n chip for serial serial communication via usb-serial converter.
It works pretty well when running a basic sketch. But as soon as i load one of the SD examples on to the board, the following gets displayed > " initializi > + rrrrrrrrrrr". I loaded the same sketch onto my uno and it works perfectly. I can even read/write data to my SD Card on the uno, but the diy board doesnt write to the SD card.
So there is 2 issues or maybe 1. The serial monitor gets falls info and spi bus does not work.
You need to provide an enormous amount of additional information if you expect anyone to do any more than guess. For example what MCU are you using, what bootloader, what clock speed etc etc
My guess is that something is causing a buffer overflow and a crash - but why ? ? ?
The MCU im using is a ATMEGA-20PU and the bootloader running on the MCU is the Arduino Diecimila or Deumilanove w/ ATmega168.
As attahhched is the out put for the DIY board > deumilanove and the bought UNO > Uno.
So as far as i can see there is no problem downloading the sketch to the deumilanove, its just that the serial print in the serial monitor does not recieve the corect data. It also keeps on printing in the serial monitor until you stop the monitor, where as the uno stops sprinting after it faild the initialization.
It almost looks like the deumilanove goes into an infanate loop and this causes the SPI bus that wirtes to the SD card not to work either. Because the SD card circuit works perfectly with the Uno.
