https://spqr.eecs.umich.edu/walnut/ for more information.

Demonstration of acoustic injection attack against a Samsung Galaxy S5 smartphone containing an MPU6500 MEMS capacitive accelerometer. The smartphone is running an app that relays the raw sensor output to Matlab on the computer. The acoustic tones cause the sensor to spell out "WALNUT" as a proof of concept that we can create tones to cause arbitrarily chosen values to be delivered to the microprocessor. Devices ranging from safety systems in automobiles to inertial measurement units in emerging satellites rely on MEMS devices for making automated decisions.