Accellerometer short

I’ve been successfully running a circuit with the MMA7260QT XYZ-axis accelerometer, sending the outputs through the ADC of an Atmega 168; ADC outputs showed good reading from all 3 axis. Vin has been powered by the 5v output on an Arduino board. I’ve now run into a situation where there appears to be an internal short between Vin and GND on the accell breakout board. Multimeter readings seem to confirm this, as well as the LCD screen I’m powering off the same 5v input going blank when GND on the accell chip is connected to the circuit GND. Is there some way the chip could have been damaged to cause a short like this? The soldering on the header pins looks clean.


I don’t know about the “short like this” part in particular, but in general, there are all kinds of ways you can destroy electronics, including electrostatic discharge and application of inappropriate voltages. If the unit was working before and now isn’t, there’s not much hope for it. For purposes of avoiding whatever caused the failure in the future, you could try to think about what might have happened right before the unit failed. I’m not sure what else you had connected, but I generally wouldn’t recommend connecting and disconnecting ground to turn things on and off.

- Jan

Thanks for the input Jan. While I don’t think I’m going to be able to isolate exactly what I did to fry the accelerometer, there was an upside. I replaced it with another version (Memsic dual-axis) that uses a PWM output vice analog. It’s giving me much better performance IRT signal to noise. It also forced me to learn a little bit about coding for interrupts to read the PWM, so the losing the component was not a complete loss.