STMicroelectronics

Open-Source Capacitive Linear Encoder Reaches 40 Micrometre Accuracy With an STM32L4 and Two PCBs

Nick's open-linear-scale uses the digital-caliper principle: a four-layer sensor board with eight transmit antennas, a passive two-layer reflector 0.1 mm away and an STM32L476RC. He reports 40 µm accuracy and a build cost of roughly $32 before shipping. The design is still in development.