I'm having a weird problem with the Adafruit LCD shield, specifically with the MCP23017 chip sitting on the I2C bus.
My setup:
Netduino Plus
4.2 firmware
My app is in VB
Using the Toolbox driver for this shield
Everything builds fine and starts up well. I get an initial sign on message to display on the LCD and can read the buttons fine. My app periodically writes new data to the LCD (about every 3 seconds or so). At random, the LCD/buttons stop working. My app continues to run fine, but when I attempt to write to the LCD or read the state of the buttons, nothing on the shield works.
I can set breakpoints in my code and everything looks fine -- it executes the Display.Write command to the LCD, but just returns without putting anything on the LCD once it is "locked up".
I suspect a problem with the I2C interface (the only way to recover from this is to power down the board).
Any thoughts?
Kelly