Input Devices

Mini Breakout Sensor Board With Analog MEMS Mic

I plan to use these mini sensor boards to measure the noise level in the open-plan office environment. By spreading out multiple of these, the noise level could not only be measured more accurately but also be triangulated by comparing the time stamps. When placing these sensors on walls and ceilings, the data communication and power supply would better be moved to wireless and battery-powered.

A video posted by Raphael Schaad (@raphaelschaad) on

A video posted by Raphael Schaad (@raphaelschaad) on


To detect sound we need sort of a microphone. Electrec is an older part that needs to be combined with an Op-amp. More modern are MEMS that come in tiny and cheap packages and in analog and digital variants. The analog one gives off current that can be converted to digital values and the digital one speaks I²S. Reflow solder: tin traces. solder bump pads. heat. Brand new in inventory

Recitation Welding and Sheet Metal

“It’s one of the most scalable manufacturing processes available, applicable from unit quantities of 1-10000s. Metal sheets are cut then formed into complex geometries allowing thin-walled structures with semi-arbitrary placement of components in 3D space, at scales from millimeters to meters.” Matthew Carney demonstrated how to prototype a simple bracket and the available tools.

Welding Shop


We use an RC circuit to filter the analog signal from the mic before ADC. Intro to RC circuits. Filter design tool. 1kΩ × 0.1microfarad = 0.0001ms