Hello, I'm working on a project for which, until recently, I was using an Arduino Uno and Anna adafruit ultimate GPS logging shield (found here: https://learn.adafruit.com/adafruit-shield-compatibility/ultimate-gps-shield). However, I am running out of memory because I am also using an LCD screen and this means that I have a bunch of libraries to include. I have an Arduino mega lying around, and I read on the above link that it may be possible to get it to work with the GPS shield. I have followed their instructions, and jumpered pin 8 to RX1, pin 7 to TX1 (along with ground to ground, and 5V to 5V, which they didn't mention but I assume you have to do). I changed the serial line like they suggested, and now am trying to follow their recommendations for the SD card. ( I am using the shield_sdlog example included with the adafruit GPS library )
This is what they say:
"For the SD card, the following may be tried, in decreasing order of recommendation: Use the Adafruit SD library, specifying pin 10 for chip select, 11 for MOSI, 12 for MISO and 13 for SCK. Edit the file utility/Sd2Card.h in the default Arduino SD library, changing line 42 to read "#define MEGA_SOFT_SPI 1" (default is 0)."
I tried to follow the first suggestion, but i'm not sure i'm doing it right. I commented out the previous definition of ledPin, because it was already 13. Then I commented out all uses of the LED pin, which I don't think should affect the functionality of the logging. Than I defined the pins they suggested, as follows:
// Set the pins used #define chipSelect 10 #define MOSI 11 #define MISO 12 #define SCK 13 //#define ledPin 13
However, when I run the program, it says that the card initiation failed, which is the same problem I have run into before when I accidentally misjumpered's Arduino Uno. I haven't tried their second suggestion, because I'm not sure if I'm supposed to do that in addition to the other pin definitions or what.
Anyway, I was just wondering if anyone had any suggestions on how to get this working. Help would be much appreciated.