Selfmade Sensor-Array Mat [THA SysEng1 project]

We are a team of five students from the Technical University of Applied Sciences Augsburg developing a custom sensor mat capable of measuring pressure, temperature, and humidity distribution across its surface.

The mat itself is self-built. Pressure is measured using a matrix of copper traces arranged horizontally and vertically, with a Velostat layer in between. Velostat changes its resistance under pressure, so each intersection of the copper traces functions as an individual sensor point. At every crossing, the resistance is measured using a voltage divider, allowing the applied pressure to be determined.

Temperature and humidity are measured using additional I2C sensors mounted on the system.

Our first PCB controls the sensor matrix. Using shift registers, the columns of the matrix are sequentially energized, while multiplexers route the corresponding voltage drops from the rows to the measurement unit. The board also includes an I2C controller for managing the environmental sensors. All analog measurements are handled by an ESP32, which then transfers the data to a PC where it is processed and visualized as a heatmap.

More infos and pictures soon...