MyoScope μPy: Design, Fabrication, and Validation of a Fully Open-Source, Low-Cost 4-Channel sEMG Platform Using Passive Dry Electrodes and MicroPython

Supplementary design files and experimental validation data for the MyoScope μPy, an open-source, low-cost (<$46 USD) 4-channel surface electromyography (sEMG) acquisition system using passive stainless-steel dry electrodes. This dataset contains: 1) Hardware_Design/: EasyEDA schematic and PCB layout files (JSON format) for both the main power management shield and the analog acquisition module, plus a complete project archive (ZIP). 2) Firmware/: MicroPython source code (main.py) for the Pyboard v1.1 (STM32F405), implementing a triple-buffering architecture for deterministic 4-channel ADC sampling at 2500 Hz with continuous microSD storage. 3) 3D_Model/: CAD files (DWG) and technical drawing (PDF) for the 3D-printed electrode bracelet. 4) Validation_Data/: Raw binary sEMG recordings (.bin, uint16 little-endian, 4 channels interleaved at 2500 Hz) from three experimental scenarios: shorted-input noise floor characterization (8 files, 240 s), floating-electrode electromagnetic susceptibility testing (36 files, 1080 s), and signal-to-noise ratio evaluation during rest and maximal voluntary contraction (28 files, 840 s). Includes Python analysis scripts (NumPy, SciPy, Matplotlib) and publication-quality figures (PDF). 5) Battery_Testing/: Charge and discharge profiles of the Li-Ion battery recorded with an external RP2040-based datalogger equipped with an INA226 current sensor at 8 Hz. Includes raw binary data, the datalogger firmware, and plotting scripts. All hardware designs are licensed under CC BY 4.0. Associated article submitted to HardwareX.