Velostat Pressure Mapping Matrix Troubleshoot

@mohjib092

Hello, I have experience with Velostat-based pressure sensors, FSR matrices, and multiplexed readouts. I can help diagnose why your new Velostat sheet gives only zeros and design a stable, repeatable solution. Likely causes include variations in sheet resistivity, inconsistent contact, or resistor/mux mismatch, all of which I can address through proper circuit design and calibration. I can guide you on resistor selection, multiplexing strategy, and Arduino/ESP32 integration to ensure reliable pressure mapping across different sheets. Best regards,

@nemanjac6

I am a power systems and control engineer with strong experience in Simulink/Simscape Electrical. I can deliver a complete low-voltage DC microgrid model with PV, wind, and bidirectional battery storage using proven droop control for stable power sharing. The model will be fully modular, well-commented, include scopes and documentation, and remain within ±5% DC bus voltage under dynamic load and source variations.

@syedfahadahmad33

Hello I just read out your description and am interested in your project. I am an Expert in Presure Mapping, and have also worked with it in the past. If you need Quality Work, then feel free to contact me Thanks

@mohamedaminea1

Hello. I have 6+ years of experience designing resistive sensor matrices and have built over 15 FSR/Velostat-based arrays up to 32×32 nodes, achieving <5% variance across sheets and stable readings over 100k+ load cycles. I have previously resolved sheet-to-sheet inconsistency by characterizing base resistance (10 kΩ–2 MΩ), contact impedance, and time-dependent hysteresis, enabling repeatable calibration across different material batches. My approach will be: (1) electrically characterize each Velostat sheet using controlled excitation and impedance profiling, (2) redesign the matrix readout using buffered row drivers and constant-current excitation instead of passive pull resistors, (3) optimize MUX timing, ADC sampling, and shielding to suppress floating and leakage effects, and (4) implement per-sheet normalization and drift compensation in firmware and Python post-processing. I will validate stability under no-load, static load, and dynamic load conditions and document measurable improvements in noise floor and sensitivity. Do you require identical pressure response across different Velostat sheets or acceptable calibrated equivalence? What spatial resolution and minimum detectable force are you targeting for the matrix? Are mechanical factors such as pre-load, backing material, or adhesive layers fixed or open to adjustment?

@AzharPlus

Hi, the issue you are facing is that Velostat material properties are not consistent across different implementations. It requires calibration and a system that resists material property drift. I have 20+ years of experience with a B.E. in Electronics (Top-Ranked Graduate). I have extensive experience working with 74xx and 4xxx series logic since the start of my career. Additionally, I am an expert firmware designer covering all mainstream MCU architectures. Contact me, I am confident that not only can I solve this issue, but we can also build long and productive work relationship. Best Regards, Azhar Chohan

@Fel85

Hi, This problem is very likely not a wiring mistake, but a system-level interaction between Velostat variability, biasing, and multiplexed ADC reading. Velostat sheets vary widely in base resistance, pressure curve, hysteresis, and contact resistance. Rebuilding the same matrix with a different sheet can easily result in all-zero readings (over-bias / ADC saturation) or random noise (floating inputs) if the design assumes identical material behavior. I can help you by doing structured troubleshooting, not trial-and-error: • Analyze Velostat electrical behavior vs pull-up / pull-down choice • Identify why the matrix works with one sheet but fails with another • Review MUX effects (leakage, settling time, impedance interaction) • Propose a stable biasing + excitation strategy tolerant to sheet variation • Suggest hardware + software signal conditioning • Define a repeatable calibration approach (per sheet or per row/column) • Validate results using your existing Python pressure-map workflow My focus is delivering a robust, explainable, and repeatable solution, not just making the current setup “kind of work”. Ready to start immediately and iterate until the root cause is fully understood. — Felipe