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PROJECT LOG · TIME-LAPSEESP32 OPTICAL ISOLATION

DIY ESP32 Wireless Camera Intervalometer

An ultra-reliable, optically isolated hardware intervalometer built for Sony cameras to capture multi-hour architectural and Holy Grail day-to-night time-lapses.

MicrocontrollerESP32-C3 / WROOMUltra-low power sleep states
Camera InterfacePC817 OptocouplerFull galvanic isolation (camera-safe)
Control ModeWeb UI & OLEDControl via mobile browser or rotary click
Battery Runtime18+ HoursSingle 18650 Li-ion cell with TP4056

The Problem with Mobile Apps & Cheap Remotes

Factory camera apps (like Sony Creators' App or Imaging Edge) frequently disconnect over Wi-Fi after 30 minutes, ruining long sunset time-lapses. Cheap wired intervalometers have fragile cords and lack the smarts to ramp interval times as the sun drops and shutter speeds lengthen.

I built a dedicated, standalone hardware trigger using an ESP32 that connects directly to the 2.5mm remote port of the camera. The optical isolator ensures zero voltage spikes can ever reach the camera's delicate mainboard.

Key Features

  • Dual Optocoupler Design: Separate channels for Half-Press (Focus / Wake) and Full-Press (Shutter Trigger).
  • Bulb-Ramping Support: Adjusts exposure duration dynamically over the course of the shoot for smooth Holy Grail sunset transitions.
  • Zero Cable Snag: Mounts directly on the camera hot-shoe inside a custom 3D-printed snap-fit case.
⚡ Electrical Safety First

Never wire an Arduino or ESP32 GPIO pin directly to your camera remote terminal. Modern mirrorless camera trigger pins pull to ground at ~3.3V or 5V, but floating potentials or ground loops can fry the camera's I/O ASIC. A 5-EGP PC817 optocoupler provides complete optical isolation.

Parts Sourcing

Everything was sourced in Cairo: PC817 optocouplers and perfboards from Makers Electronics, 2.5mm stereo jacks and switches from RAM Electronics in Bab El-Louq, and 18650 cells from Micro Ohm.