Sukasa

Taking what you said into mind I went back and tried using 10600Khz instead of 10000 just for fun.

It worked beautifully. Doubled the transfer speed and now my project is far, far more responsive.  Thanks!

I'm on a stock N+2, so 168Mhz if I recall

(copy-paste from the breakdown on the Adafruit forums)

I was able to figure it out!

The thermocouple modules you sell have 10k pullups on the inputs to their SClk lines... and the protection diodes are used to pull the clock line low. Of course, this means that at any given time these modules are backfeeding 3v3 onto the SPI Bus' SClk. Whoops!

The solution I had was to place a PNP transistor in, to make the High-Low signal from the Netduino into an Open-Drain signal from the PNP. When the Netduino pushed high, the PNP would stop conducting and the thermocouple modules would pull themselves high. When the netduino pulled low, the PNP would conduct and pull the thermocouples low. When the uC was floating, the PNP would prevent backfeeding pulses that messed up the clock signal to the LCD.

So, long story short: the Adafruit thermocouple breakouts like to pull up the SPI bus' clock line, and the Adafruit 2.2" Lcd is susceptible to that, leading to "phantom" clocks and a few nights of headaches.

This might be silly, but what are your build configurations?  I commonly get this error when either no deploy checkboxes are filled in, or more than one is.

Can SDHC support get put on that feature wishlist?  It's getting harder and harder to get ahold of <=2GB cards these days