Hi everybody; I have this funny problem and it is making me crazy. I am making a data logger with 10 inputs and Arduino Ethernet Shield to log the inputs into a micro SD card. I want use a 128x64 graphic LCD to monitor these inputs. But as soon as I use the command "sd.begin(4,SPI_FULL_SPEED)" or "card.init(SPI_FULL_SPEED, 4)" my LCD starts displaying some nonsense stuff. I have changed my speed to HALF_SPEED too, but nothing has changed. I am sure that everything else is correct. I have changed pin configuration for LCD too and again no result. When I program my Arduino Mega 2560 with other program in which i have not used SD card I have satisfactory results. Is there anyone else who might have had a problem like mine?
happyrich: I have changed pin configuration for LCD too and again no result.
Configuration to what? This sounds like pin 4 is being used by the LCD.
Thanks Nick_Pyner you reminded me of something important. I figured it out. I have been using 53 and 51 pins on arduino mega 2560. and now I'm not using them any more. thanks for your reply.