Professor Roger Howe taught me some of the fundamental principals of MEMs-based accelerometers. We set off to develop some exercises for the historically-theory-heavy Stanford Eng. 240 course.
Turns out that decent "macro" accelerometers can readily be made using modern PCB fabrication techniques! This allows students, hobbyists, etc.. to explore certain accelerometer design principals without traditional MEMs fabrication techniques.
<aside> 💡 By measuring the capacitance between two parallel plates (one of which suspended by "springs" of the PCB) you can determine the force acting on the plate and back out the axial acceleration. Cool!
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I used the TI FDC2212 (FDC2214) capacitive sensing IC from Texas Instruments to readily make 28-bit (❗) capacitive measurements in an embedded formfactor. I couldn't find any low-cost FDC2212 breakout boards, so I built one. We wanted to decouple the embedded-design aspect of the project from the mechanical and electrical considerations, so I also put together a CircuitPython driver for the FDC221X devices- allowing them to easily be controlled via plain-text python syntax.
One of the first labs for the students is to assemble an open-source SAM32 development board to enable future sensor driving / data collection.
PCB accelerometer board (left) with FDC2212 breakout (right) and SAM32 dev board (middle)
Students began working with the PCB accelerometers and capacitive sensing techniques in Fall 2019 as a result of tireless efforts of Eng. 240 TA: Payton Broaddus. Payton has made his teaching resources available here ________.