A camera app that turns sound into
photos, videos and timelapses.
Short description

Hands-free capture triggered by sound

FFT Trigger Cam analyzes your microphone input using a live spectrum (FFT) and converts it into camera actions: Start (begin recording), Action (photo or timelapse frame), and End (stop recording / finalize timelapse).

  • Photo mode: Action triggers take a photo (optionally delayed).
  • Video mode: Action triggers create a timelapse by capturing frames into an encoder.
  • Three independent channels: Start / Action / End can each be Off, Simple, or Signal.
  • Profiles: Save and load different trigger setups.

Demo recordings were captured on iPhone 15 and Google Pixel 9 Pro.

What can you do with it?

Trigger-based photo, video, and timelapse

Use sound to control the camera without touching the screen: start recording on a tone, capture timelapse frames on repeated events, and stop recording on a final signal.

  • Start: Begin recording when your trigger condition is met.
  • Action: Take photos (photo mode) or capture frames for timelapse (video mode).
  • End: Stop recording or finalize / discard a timelapse.
iOS demo video
Android demo video
How to set up

Select a trigger, configure it, then go live

The main screen is your starting point. Pick one of the three trigger channels, set its mode, configure the parameters, and test it — then activate FFT ON inside the camera view to start capturing.

  • Select channel: choose Start, Action, or End.
  • Set mode: Off, Simple, or Signal per channel.
  • Configure: adjust frequency range, threshold, and timing for the chosen mode.
  • Test: verify detection with the live TEST indicator before recording.
  • Activate: open the camera view and tap FFT ON to make the trigger live.
How to set up - iOS
Setup (iOS)
How to set up - Android
Setup (Android)
General settings

Frame delay, frame rate, sampling, and FFT resolution

Fine-tune how the audio pipeline behaves and control camera frame rate for power saving:

  • Frame delay: wait a defined time before executing an Action capture.
  • Video frame rate: limit the camera FPS to reduce power consumption during long sessions.
  • Sampling interval: how often the FFT is evaluated (faster = quicker reaction).
  • FFT resolution: frequency bucket width in Hz (larger = more stable, less detail).

Presets let you switch between Max performance, Power saving, or Reset to defaults in one tap.

General settings - iOS
General settings (iOS)
General settings - Android
General settings (Android)
Trigger mode

Off: disable a trigger channel

Setting a trigger channel to Off disables it entirely. Use this to reduce complexity — only activate the channels you actually need for your use case.

Trigger Off - iOS
Trigger Off (iOS)
Trigger Off - Android
Trigger Off (Android)
Trigger mode

Simple: frequency band above threshold

Simple mode fires when energy in a selected frequency range exceeds a threshold for a minimum duration. Add a cooldown to prevent repeated triggers.

  • Band: choose min/max frequency (Hz).
  • Threshold: required signal strength to trigger.
  • Min length: filter out very short peaks.
  • Cooldown: avoid rapid re-triggering.
  • TEST dot: a live indicator that lights up whenever the current signal would fire the trigger — always active, even during recording.

Use case: a clap, whistle, or any broad-spectrum burst that is reliably louder than the ambient noise.

Trigger Simple - iOS
Trigger Simple (iOS)
Trigger Simple - Android
Trigger Simple (Android)
Trigger mode

Signal: multi-slot pattern matching

Signal mode matches a sequence of frequency snapshots against what the microphone hears in real time. Each slot represents one sampling interval, so the pattern spans multiple time steps.

  • Signal slots: define the expected frequency content for each time step.
  • Band & threshold: frequency range and minimum energy per slot.
  • Min signal length (recording): minimum duration required to fire the trigger during recording.
  • Min signal length (testing): separate minimum duration for the live TEST indicator.
  • Overlap: how many slots must match before the trigger fires.
  • Tolerance: allow small frequency deviations for real-world stability.

Use cases: repeated beep sequences, multi-tone signals, or any pattern that needs to be distinguished from random noise.

Trigger Signal - iOS
Trigger Signal (iOS)
Trigger Signal - Android
Trigger Signal (Android)
Live view

Monitor triggers in real time during recording

The live screen runs alongside your camera during actual recording. It shows the spectrum in real time so you can verify that your triggers are firing correctly in the field.

  • View the live FFT spectrum as sound reaches the microphone.
  • See the overlap of detected signals against your configured slots.
  • Compare currently measured frequency ranges with your configured thresholds.
  • Confirm that triggers fire when expected — and stay silent when not.
Live screen (iOS)
Live screen (Android)
Download

Get FFT Trigger Cam

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