FlexiTac Mini: A Compact, Daisy-Chainable Readout Board for FlexiTac
University of Electronic Science and Technology of China
Open-source hardware (GitHub), 2026
A 27.5 × 22 mm board with a 150 MHz Cortex-M4 and 12-bit ADC (60+ FPS). Two 1 Mbps UART ports daisy-chain sensors: each node forwards its neighbours' frames, so the host reads the whole chain from any node's USB port.
Abstract
SUMMARY (compiled from project sources)
FlexiTac Mini is a compact, open-source readout board for FlexiTac sensors. At 27.5 mm × 22 mm with two M2 mounting holes (23 mm apart), it is small and easy to install. An Arm Cortex-M4 MCU (AT32F415KBU7-4) running at 150 MHz with a 12-bit ADC replaces the original 16 MHz, 10-bit Arduino Nano, raising tactile upload to over 60 FPS (70 FPS in testing). The board also supports chain connection: two UART interfaces run at 1 Mbps, and the MCU sends its local tactile data out of both UART Tx ports while appending the bytes received on both UART Rx ports to its USB transmit buffer. This topology daisy-chains multiple FlexiTac sensors, so the host PC can read the entire bus from any node's USB port.