Plantcam: Square Autofocus OV5640 timelapse camera

Plant Cam: Square Press-Fit Socket for Autofocus OV5640

Plant Cam is a compact timelapse camera made exclusively for plants. I started this project with the goal of spotting problems early, understanding when to water, and monitoring my plants anytime, anywhere - even when my friends were taking care of my small apartment.  Timelapse videos give you a far better understanding of how to best care for plants and see what different amounts of light, water do to their health.

Background

This object is the first mount I quickly prototyped: a tall, narrow "arm" with a square pocket at the top and a tripod thread at the base. The square socket is meant for the square form factor the autofocus OV5640 camera module, so there aren't ant screws, brackets, or adhesive needed.  I've decided to share this design because its a great quick way to get started with the Seed Studio esp32-sense s3 board and a tiny autofocus camera (but actually, this design literally ONLY works with this version of the esp32 and if your ov5640 has one of the 72mm long ribbon cables).

Plant Camera IO — official plant cam , More information 

Why I built this plant camera mount

Square autofocus OV5640 modules are a different animal from the larger m12 mount lens variants. They're a compact square block with a voice-coil lens stack on top (used for autofocus / motion stabilization), and critically, most of them ship with no mounting holes at all.  I wanted to avoid using hot glue or zip ties, both of which let the sensor creep over a multi-week plant timelapse (it's really surprising how much thermal cycling can cause these things to move around!). A press-fit socket grips the module body on all four faces instead, which is the only thing that reliably holds the position.

That stability is the whole idea: a steady frame is what turns a huge pile of images into a timelapse you can actually render into a good looking video result, where early droop, leaf curl or stretch shows up days before you'd notice it by eye.  You can see some of my test setups below using the plant camera near a seed tray and my test rack.  One tip I'd recommend is that it's possible to "lock" the voice coil into "infinite" focus - since by default these camera modules can have a hard time focusing on objects closer than 10cm from the lens.

Parts

• Square form factor autofocus OV5640 module (VCM lens, ~8.5 mm square body)

• XIAO ESP32S3 Sense · pre-soldered option

• Aluminium heat sink for XIAO, 2pcs (usually included with esp32-s3 sense)

• 1/4"-20 UNC brass heat-set insert, ~7.9 mm OD

• ~30 g PETG or PLA

example ov5640 "square" form factor

Printing the plant cam mount

0.2 mm layers, 4 perimeters, 30% infill, no supports (specifically for the heat insert).

Assembling the plant camera:

1. Heat-set the tripod insert: 7.4 mm pilot hole, iron at 230 °C, press straight and slow until flush. Cool fully before threading.

2. Stick the 10 × 10 mm heatsink to the thermal pad under the XIAO first ~ it's fiddly later.

3. Plug OV5640 into the daughter board.

4. Drop the dev board stack (esp32 and sense daughter board) into the rear shell, aligning USB-C port with the back.

5. Seat the OV5640 and its heatsink in the keyed front pocket. (INSERT FROM THE BACK)

   1. it's really important to only push gently with your finger on the back and to not press or disturb the floating camera lens on the front of the unit. 

   2. This can actually be easier to do if you apply the heatsink to back of the camera first.

6. Ensure ribbon cable is aligned

7. Attach adhesive heatsink to back of camera module (leaf shot).

Fit note for the square socket: module dimensions vary between suppliers, so measure across the body — not the lens barrel — and aim for roughly 0.15 mm of interference. Press on the PCB edges only; never push on the lens stack, which will damage the autofocus travel.  I printed these on both a Bambulab H2S and Prusa Core L.  Assuming your printer is properly calibrated the tolerances I use here should be fine.  If not, I found a quick solution by adding scotch tape on one side of the camera unit!

Learn more about plant our plant timelapse camera