Build the camera

IKEA 365+ 180ml — available new (£6 for a pack of 3) or reused from eBay, Vinted, or charity shops.

⚠ Read before you begin

Wire the FTDI adapter to the ESP32-CAM using female-to-female jumper wires: GND→GND, VCC (5V)→5V, TX→U0R, RX→U0T. To enter programming mode, also connect the IO0 pin to GND. Remove this wire after programming.

Download and install the Arduino IDE (free). In Preferences, add this URL to Additional Boards Manager URLs:

Go to Tools → Board → Boards Manager, search "esp32" and install the Espressif package. Then select AI Thinker ESP32-CAM as your board. Open File → Examples → ESP32 → Camera → CameraWebServer. Enter your Wi-Fi name and password in the sketch, select the right COM port, and click Upload. Once uploaded, remove the IO0–GND wire and press Reset.

Open the Serial Monitor (Tools → Serial Monitor, 115200 baud). After reset, the ESP32-CAM will print its IP address. Open that address in a browser on the same Wi-Fi network. You should see a live video stream. Note the IP — you will use this to view footage in the field via a mobile hotspot.

The rope system tells you which direction the camera is pointing without opening the jar. Drill one 4mm hole in each of the two opposing lid flaps. Thread a short length of rope through each — use two clearly different colours (e.g. blue and orange). Tie a knot on the inside to secure. Always note which colour corresponds to which side before deploying. This is how you know where the camera is looking.

De-burr both holes carefully using a scalpel or pocket knife — run the blade lightly around the rim to remove any raised plastic edges before threading the rope. Collect all plastic swarf on a sheet of paper immediately after drilling and dispose of in general waste.

Place a small piece of foam or adhesive velcro on the inside base of the jar. Press the ESP32-CAM onto it with the camera lens facing the base glass. The lens should be centred and as close to the glass as possible without touching. Route the USB cable through the jar opening — the cable exits under the lid, not through it.

The Lite version requires no drilled cable hole and no cable gland. The USB cable simply runs under the edge of the lid when closed — the jar's rubber seal provides enough compression to make it watertight. Press the lid down firmly. The rope handles sit outside the jar and can be used to position and retrieve it.

Before connecting anything, set the XL6019 output to 5V using a small flathead screwdriver on the potentiometer. Turn the pot and measure the output with a multimeter until it reads 5.0V — do this before connecting the ESP32-CAM.

Strip the bare wire ends from the LiPo's SM-2Pin JST pigtail (red = positive, black = negative). Insert them into the XL6019 input screw terminals (IN+ and IN−) and tighten with a screwdriver. Connect short wires from the XL6019 output terminals (OUT+ and OUT−) to the ESP32-CAM's 5V and GND pins. No soldering required — screw terminals grip the bare wire ends directly.

Charging the LiPo: When the battery is low, open the jar and unplug the LiPo's JST-PH 2.0 connector from the XL6019. Plug it into any port on the 6-channel USB charger, and connect the charger's USB-A plug to any USB charger or laptop. The per-port LED will indicate charging status — typically red while charging, off when full. Set the charger to 0.6A for a 1300mAh battery (1C rate). A full charge takes approximately 2 hours. Never charge while the jar is sealed or submerged.

Power on by connecting the LiPo. Connect your phone to the same Wi-Fi hotspot the ESP32 was configured with. Open the camera's IP address in your phone's browser to confirm the live stream. Seal the jar and submerge in a bowl of water for 30 minutes to check for leaks before field use. A 1000mAh LiPo provides approximately 1.5–2 hours of streaming. A 2000mAh battery extends this to 3–4 hours.