Solar harvesting Wi-Fi camera

An ESP32-CAM module is a low-cost device based on ESP32-S module, an OV2640 image sensor and Micro SD slot. The module is not designed for low energy consumption, however, after some tweaks, the power consumption can be lowered to a level that is usable for short periods of time, powered by solar energy. The project presented here is a reasonably robust, dust-resistant and waterproof experimentation platform, using commercial off-the-shelf components. Ideal for outdoor usage.

Solar harvesting Wi-Fi camera ready to be placed outside

Key component: ESP 32 CAM

Simplified diagram

Lowering power consumption

ESP32-CAM wasn’t designed to be a low power device. Without modifications, deep sleep current measured was 2.8 mA, it leaves much to be desired.

Deep sleep current measurement without modifications

Some people on the Internet already ventured in the following modifications:

  • Removed 5 V to 3 V voltage regulator, the camera will be powered directly from a 3.2 V LiFePO4 battery.
  • Break trace that powers the camera from 3.3 V and wire to MOSFET Q2 who switches on 2.8 V and 1.2 V voltage regulators.
  • Remove onboard led and wire GPIO33 to 5 V pin (this pin is already isolated after regulator removal) to use it externally.

These modifications lowered deep sleep current to 0.8 mA, which is scandalous for a low power device, however, is a substantial advance from the 2.8 mA without modifications.

Modifications and final result, Polyimide tape used to protect fine wir

Bill of materials

Parts used




  • Sample Firmware takes photos and send them to a server using HTTP POST - download it
  • Sample Golang server for image upload via HTTP POST - download it



The basic platform consists of a waterproof enclosure for sport cam and a printed circuit board with the appropriate size to fit inside.

Basic platform components

The proposed enclosure is pretty common, easy to find and inexpensive. Opens and closes without screws and has a mounting point where different mounting accessories can be installed.

The printed circuit board was designed to place ESP32-CAM near the window where the camera lens was to be located. The module can be positioned in two different orientations to maximize area, depending on the selected components.

AAA battery clip added, female connectors to plug/unplug module easily and header pins for programming, because the board does not have such circuitry. Also, a red LED for debugging purposes was added.

Board with all components

Energy harvester

The camera gets its energy from solar panels installed inside the enclosure, which means that the area available is small, so a way to maximize its efficiency is needed. A harvesting module based on BQ25504 chip was used. This device boosts solar panel voltage and is able to do that with voltages down to 130 mV!, is therefore able to supply current for storage in the battery, even without direct light hitting the panel.

Energy harvesting module attached...

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