TOOLS
Calculations we run every week, put in the browser: acoustics, electronics, protocols, data formats. They open in a second, run locally and ask for no registration. Each tool states the method it applies and where it stops, and a wiki documents it.
Acoustics tools
Building & room acoustics
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Composizione livelli sonori
Logarithmic sum of several sound levels and background-noise correction, with the ISO 1996-2 thresholds (UNI 9884 is withdrawn).
Demonstrative tool for composing sound levels. Dynamic list of sources (level in dB, A/C/Z weighting, optional label); energetic sum L = 10·log₁₀(Σ 10^(Lᵢ/10)) with a contributions table and bar chart. Optional background-noise subtraction section with the ISO 1996-2 thresholds (ΔL > 10 dB negligible, 3–10 dB corrected, < 3 dB unreliable: the value shown is an upper bound).
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LEX,8h — esposizione al rumore
Daily personal noise exposure level, against the action values and limit value of Art. 189 of Italian D.Lgs 81/08.
Demonstrative tool to compute a worker’s daily personal noise exposure level LEX,8h, from one or more shifts with distinct level and duration plus the peak level L_Cpeak. It applies LEX,8h = 10·log₁₀[(1/8)·Σ Te·10^(LAeq/10)] and returns the Italian D.Lgs 81/08 band relative to the action values and the limit value, with the related preventive measures and a per-shift contribution table.
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Simulatore di sala
Simulate clarity and reverberation (C50/C80/EDT/T30) in a rectangular room with an image-source lattice that is exact within the ideal specular shoebox model, and a listening-point heatmap.
Demonstrative tool for room acoustics. In a rectangular (shoebox) room place the source and receivers, choose the materials of the 6 surfaces (per-band α from the library) and read C50, C80, EDT and T30 per octave band 125–4000 Hz: early reflections from an exact Image Source Method over the image lattice, diffuse tail from Eyring/Sabine. Heatmap of the chosen metric on the listening plane and before/after panel comparison. Rectangular geometries only, pre-dimensioning and teaching.
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Tempo di riverberazione
Reverberation time T60 calculator per octave band — Sabine, Eyring, Millington — with a materials library and air absorption.
Demonstrative tool for building acoustics. From volume, total surface and the surface inventory (material + per-band α from the library, editable) it computes the reverberation time T60 over the 6 octave bands 125–4000 Hz with the three classic formulations — Sabine, Eyring, Millington — plus air absorption (ISO 9613-1, optional). Table output, T60-vs-frequency chart and a summary card. A pure calculator: no regulatory comparison.
Environmental acoustics
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Mappa acustica
Visualise sound-level measurements and compute propagation with diffraction on real OSM buildings.
Demonstrative tool for environmental acoustics. Measure mode visualises sound-level surveys (CSV with lat, lon, Leq). Predict mode computes ISO 9613-2 propagation with a simplified model per octave band (63 Hz – 8 kHz): geometric divergence, ISO 9613-1 atmospheric absorption, a G-factor ground effect, and Maekawa diffraction on buildings fetched live from OpenStreetMap via Overpass API.
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Calcolo barriere acustiche
Compute sound-barrier attenuation with the ISO 9613-2:2024 §7.4 screening with lateral diffraction, or Maekawa. In development.
Demonstrative tool to verify the effectiveness of a noise barrier. Line (road/rail), area (industrial) or point source; barrier drawn as a polyline with height; receiver grid. Computes Insertion Loss with selectable diffraction: ISO 9613-2:2024 §7.4 screening with lateral diffraction, or Maekawa, in octave bands, with a banded/isoline map, vertical cross-section and CSV export. Shares its physics engine with the Acoustic map tool. A demo: expert use needs a model adequate to the methodology and a technician responsible for it. Optionally fetches real buildings from OpenStreetMap via Overpass API for spatial reference; buildings can participate in the calculation as passive obstacles (worst-screen wins, simplified model — not rigorous ISO 9613-2 multi-screen).
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Criterio differenziale L. 447/95
Check of the Italian differential immission criterion (Law 447/95, DPCM 14/11/1997 Art. 4): 5/3 dB limits and exemptions.
Demonstrative tool for checking the differential immission criterion inside dwellings. For the daytime and night-time periods it computes ΔLr = Lr,ambient − Lr,residual and compares it with the limits in DPCM 14/11/1997 Art. 4 (5 dB day, 3 dB night), handling the §2 negligibility thresholds for windows-open and windows-closed measurements. An Italy-specific legal criterion — not a generic international method.
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Maekawa explorer
Explore acoustic diffraction over a barrier: geometry → Fresnel number → Maekawa attenuation.
Interactive demonstrative tool for single-edge (knife-edge) diffraction. From barrier height, source-barrier-receiver distances and frequency it computes the path difference δ, the Fresnel number N and the Maekawa attenuation (analytic approximation of the Maekawa curve, 10log10(3+20N), clamped at 25 dB by the implementation), with a side diagram and an Att(N) curve. Shares the acoustic-physics library with the Acoustic map and the Barrier calculator.
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Limiti rumore stradale DPR 142/04
Compliance check of sound levels at the receiver against the Italian DPR 142/04 road-noise limits.
Demonstrative tool for environmental acoustics. From the road classification (A–F, new or existing), receiver distance, type (generic or sensitive) and daytime/night-time L_Aeq levels it checks compliance with the limits of Italian DPR 30/3/2004 no. 142, using the Annex 1 noise-pertinence bands; outside the band and for E/F roads it applies the DPCM 14/11/1997 limits. Per-period result with margin, regulatory reference and a schematic plan. Cross-linked with the Acoustic map. Tables verified against the decree text.
Electronics & embedded tools
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Gerber Viewer
Load the Gerber + drill files of a PCB (multi-file or .zip) and view the composed layers, with pours and clearances rendered correctly.
Printed-circuit-board viewer: drop the RS-274X Gerber files and the Excellon drill of a board (or a .zip exported from the CAD) and see the layers overlaid — copper, solder mask, silkscreen, drill, outline — with per-layer toggles, per-side colours, transparency, zoom/pan and PNG export. Automatic layer recognition with manual assignment for ambiguous cases; GPU rasterization (WebGL2) that renders pours and clearances correctly.
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USB-PD Decoder
Decode and build USB-PD Power Data Objects: paste the hex PDOs to read voltages, currents and PPS/EPR profiles — or generate the PDO from values, ready for firmware.
Bidirectional USB Power Delivery tool. Decode mode parses raw Source Capabilities — Fixed, Battery, Variable, PPS (APDO) and EPR/AVS — showing decoded fields and the 32-bit bit-field map. Encode mode builds a PDO from values and returns the hex ready for firmware. Includes a negotiator that simulates sink→source selection. Born alongside our open-source USB-PD stack for the PTN5110.
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MIPI CSI-2 Bandwidth Calculator
Compute the bandwidth of a MIPI CSI-2 camera interface: from resolution, frame rate and bit depth get the required data rate and check whether the lanes can carry it.
Tool for sizing a MIPI CSI-2 camera link. Enter resolution, frame rate, pixel format (RAW8/10/12/14, YUV422, RGB888) and D-PHY configuration (lane count, lane rate): get the required data rate, lane utilization, headroom and the minimum number of lanes needed. Born from our camera-capture work on STM32.
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Crystal Load Cap Calculator
Compute a crystal's load capacitors from the datasheet CL and stray capacitance — the detail that makes (or breaks) the clock.
Tool to size the load capacitors of a crystal oscillator. From the crystal's nominal CL and the PCB+pin stray capacitance you get the two cap values, the nearest E-series value and the resulting error on the effective CL. A wrong value here shifts the frequency and can fail compliance tests.
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UART Baud Rate Error
From the peripheral clock and target baud get the divisor, actual baud and error % — and find out whether your UART really communicates or fails on frames.
Tool to check a UART configuration. Enter the peripheral clock, desired baud, oversampling (8/16×) and optional fractional divisor: get the divisor, the actually generated baud, the percentage error against target, and a table of all standard bauds at that clock. Beyond ±2-3% error the link starts dropping frames.
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Analog Filter & Bode
Design passive RC/RLC and Sallen-Key filters up to 2nd order: pick topology and values, read cutoff, Q and the Bode plot — or start from frequency and get the components.
Tool for analog filters up to second order. Analysis mode: enter R/L/C and topology, get cutoff frequency, Q factor and an interactive Bode plot (magnitude and phase). Design mode: start from the cutoff frequency (and Q for 2nd order) and get component values with the nearest E-series part. Includes Sallen-Key active synthesis with an op-amp.
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IIR Filter Designer
Design digital IIR filters (Butterworth/Bessel, lowpass/highpass): pick order and cutoff, read the frequency response, poles/zeros and biquad coefficients — with CMSIS-DSP-ready export.
Designing digital IIR filters as a cascade of second-order sections (SOS). Set type (lowpass/highpass), family (Butterworth or Bessel), order (2–8) and cutoff relative to the sample rate: get the magnitude and phase response, the pole-zero map on the unit circle, the biquad coefficient table and the coefficient export for arm_biquad_cascade_df2T (CMSIS-DSP). Coefficients validated against scipy.signal.
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PCB Trace Designer
Size a PCB trace: width for current and temperature (IPC-2221) and controlled impedance for microstrip/stripline, in a single tool.
Two PCB trace design tools in one. Trace width: from current, temperature rise and copper thickness get the minimum width per IPC-2221, with resistance and voltage drop. Controlled impedance: from geometry and dielectric compute the Z0 of microstrip and stripline, or start from the target impedance (50, 90, 100 Ω) and get the width.
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PDN / Decoupling Planner
From a power rail's target impedance get the decoupling network: bulk, HF capacitors and ripple margin.
Demonstrative tool for sizing a rail's decoupling. From the allowed voltage ripple and the transient switching current it computes the target impedance Zt = ΔV/ΔI; based on Zt and the maximum frequency of interest it suggests a decoupling network (bulk capacitance + HF capacitors, indicative count and values) to keep the impedance magnitude below Zt, with an estimate of the bulk-to-HF antiresonance frequency.
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ADC / DAC Resolution & SNR
From resolution, Vref and sample rate get LSB, theoretical SNR, dynamic range, ENOB and Nyquist frequency.
Demonstrative tool for sizing a converter. From the number of bits, reference voltage and sample rate get the LSB size, the ideal SNR (6.02·N + 1.76 dB), the dynamic range and the Nyquist frequency; entering a measured SNR or SINAD yields the effective number of bits (ENOB).
Software tools
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Image Processing Lab
Image processing workbench: kernel convolution, Bayer demosaicing and histogram/exposure analysis on your own image or a sample.
Three image-processing tools in one: apply convolution kernels (blur, sharpen, Sobel/Laplacian edge detection), explore Bayer sensor demosaicing (RGGB and variants), analyse histogram, luminance and exposure clipping. Born from our work on CMOS sensors and embedded camera pipelines. The image is resized for processing.
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FFT / Window Explorer
Explore how analysis windows (Hann, Hamming, Blackman, flat-top…) shape a signal's FFT spectrum: spectral leakage, ENBW, scalloping and side-lobes.
Demonstrative tool for spectral analysis. Compose a test signal (sum of sinusoids + optional noise), choose sample rate, FFT length and window, then read the time-domain signal, the FFT spectrum in dB and the window metrics (ENBW, scalloping loss, main-lobe width, side-lobe level). Illustrates the resolution/leakage trade-off.
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Data Format / Endianness Inspector
Paste a hex buffer and interpret it as 8/16/32/64-bit integers (signed/unsigned) and IEEE 754 single/double floats, in big and little endian.
Demonstrative tool to read raw data from instrumentation and protocols. Paste the bytes (with or without 0x, spaces, commas), pick the offset, and see every interpretation at once in big and little endian; for floats, the IEEE 754 decomposition into sign, exponent and mantissa with the reconstructed value. Inverse mode: from a value, get the bytes.
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Calcolo incertezza di misura (GUM)
Uncertainty budget per the GUM: type A/B components, distributions and divisors, quadrature combination, expanded uncertainty U = k·u_c and a percentage budget.
Demonstrative tool for measurement-uncertainty propagation per the GUM guide. List the uncertainty contributions (type A statistical or B estimated), pick a distribution (normal, rectangular, triangular) and sensitivity coefficient for each, and get the combined standard uncertainty u_c, the expanded one U = k·u_c and the budget with each contribution's percentage weight.
Got a specific use case?
These tools come from real client work. If you have a use case that would call for a similar tool, let's talk.