I am working with a r3 Uno and the official Wifi shield. In order to get it to work, I had to jumper pin 3 and 7, and use IDE 1.0.2. I see there are some threads here discussing that perhaps upgrading the shield's firmware will allow me to use the latest IDE, I haven't tried that yet.
Anyway, I also need to use the analog comparator with a piezo element. To do that, I need pin 7 and 6. But pin 7 is tied to 3, which makes it not work since the analog comparator is comparing the voltage difference between 6 (AIN0) and 7 (AIN1).
Does anyone know how to get this to work? What's the purpose of tying pins 3 and 7? Or perhaps can the analog comparator be set up to use different pins for comparison (instead of just 6/AIN0 and 7/AIN1)? From the Uno R3 schematic, I see there are other AIN pins, but I don't see how any of the other ones are accessible via IO pins.