A while back someone was having trouble with their MMA7661 accelerator not reading. I had the same problem when aI first got mine, found I didn't have the SL pin activated and told the poster to use an analog pin to power the digital input to wake the accelerometer. I have been doing this on a project that has been running for a month, no problems. After reading the datasheet closer, I see that the max voltage for the I/O pins is 3.6v. Why does it still work?
Could there be a voltage divider for the digital pins on board the breakout? I can't seem to find a schematic for it anywhere.
The bad thing is I ordered some circuit boards with this setup aand I think I need a voltage divider on this pin to be safe.
I guess that's why they call it a prototyping service.
TomJ