nmdFFT Demos (recorded)

spectrum landscape · 4096-point FFTs · newest row in front · drag to turn

waterfall · −fs/2 … +fs/2

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FFTs per second

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MS/s transformed

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MS/s from the source

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blocks dropped (total)

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accelerator busy

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CPU used (4 cores)

Signal (PL test generator)

Speed Tone bin Noise bursts

Stream

Source rate Floor Range Colours

What runs where

The pattern generator in the PL writes 64-bit beats of int16 I/Q into a DDR ring; the accelerator transforms each block of 16 × 4096 samples as it lands. The A53 only hands out ring slots (a small C loop) and turns ~60 blocks a second into the rows you see; everything else is the accelerator.

Image

2-D spectrum (log magnitude, centred) — paint here

Inverse FFT of the painted spectrum

removedboosted ×4symmetric strokes keep the image real

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filtered images / s

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round trip, ms

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inverse FFT call, ms

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accelerator, ms

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CPU used (4 cores)

Select Image

Resolution

Brush

Size mirror strokes through the centre

Filters

Radius animate the radius (runs flat out)

inverse 3-D FFT of shaped random phases · every frame is a new FFT · drag to turn, wheel to zoom

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volumes / s

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accelerator per 3-D FFT, ms

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3-D FFT call incl. copies, ms

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CPU spectrum + reduce, ms

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CPU used (4 cores)

Field (on the board)

FFT grid

Spectral slope Fine detail Evolution speed

Rendering (in your browser)

Density contrast Threshold Brightness Colours auto-rotate

one 2²⁴-point FFT per frame · wheel to zoom, drag to pan, double-click for the whole band

spectrogram of this view · one row per 2²⁴-point FFT · newest on top

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2²⁴-point FFTs / s

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accelerator per FFT, ms

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FFT call incl. copies, ms

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span shown

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bins per pixel

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CPU used (4 cores)

Fly to

fs = 2²⁴ Hz, so each of the 16,777,216 bins is exactly 1 Hz wide. Moving: a tone drifting across the band, one hopping between 6.4 and 8.2 MHz every frame, one swinging around 3.5 MHz.

Signal (made on the board)

Drift speed Noise in the samples peak hold

Aperture (512²) — draw on it

Far-field intensity, |2-D FFT|², log scale

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patterns / s

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round trip, ms

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FFT call incl. copies, ms

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accelerator, ms

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CPU used (4 cores)

Aperture

Motion

Brush (draws when Still)

Optics

FFT grid (zero padding: finer fringes)

Light

Dynamic range

3-D ultrasound · plane wave, f-k migration · 2 three-D FFTs per volume · drag to turn, wheel to zoom

Azimuth slice (x–depth)

Elevation slice (y–depth)

C-scan (x–y at one depth)

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volumes / s

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accelerator per volume, ms

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CPU Stolt remap, ms

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time per volume, ms

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CPU used (4 cores)

Probe (simulated on the board)

Matrix array

Dynamic range

3 MHz, half-wavelength pitch, 256 samples per element (16 mm). Phantom: speckle, an anechoic cyst, four point targets and a bright sphere orbiting through the volume.

View (in your browser)

Threshold Brightness slices follow the sphere auto-rotate

4-D imaging radar · 77 GHz · range × Doppler × azimuth × elevation → point cloud · drag to turn, wheel to zoom

Range–Doppler map, all channels integrated · circles: CFAR detections

Bird’s-eye view · outlines: the true objects

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frames / s

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points per frame

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CFAR detections

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accelerator per frame, ms

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radar pipeline per frame, ms

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front-end simulation, ms

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CPU used (4 cores)

Radar (simulated on the board)

Virtual array (azimuth × elevation)

Waveform (samples × chirps)

Ego speed CFAR threshold Angle peaks within freeze the scene (radar pipeline only)

View (in your browser)

Colour

Camera

Trail true objects static points

nmdFFT-256-K26 live

Signal (PL test generator)

Stream

What runs where

Select Image

Brush

Filters

Field (on the board)

Rendering (in your browser)

Fly to

Signal (made on the board)

Aperture

Optics

Probe (simulated on the board)

View (in your browser)

Radar (simulated on the board)

View (in your browser)

One frame on the board