Woah Tom, that worked! I was able to go all the way from 6 down to 2 ... and that's as far as I could go.
Now for the next issue: none of the other sketches work. They all fail at the initialization stage. They all have this check in them which fails:
Serial.print("Initializing SD card...");
pinMode(10, OUTPUT);
if (!SD.begin(4)) {
Serial.println("initialization failed!");
return;
}
From reading the comments in the files, pin 10 must be left as an output, even when not used ... and I'm not using it. Still have the card's CS pin connected to pin 4 (exact setup as when I running the CardInfo sketch.)
It's an instant failure, when I open the serial console, no delays (like it's trying to access it) ...
One thing I noted, this sketch doesn't have the .init() line in it as with the CardInfo one.