Ever wondered what kind of critters visit your garden whenever you’re not around to scare them off? With the Wildlife Cam Kit, you can find out. Its PIR sensor will sense any movement in the vicinity and trigger its Pi Camera Module to take a stealthy snap of whatever’s passing by.
The full article can be found in The MagPi 48 and was written by Phil King
You may recall that we’ve followed the progress of this Kickstarter-funded project in previous issues of The MagPi, but now it’s finally out in the wild. Designed by Naturebytes, a trio of digital makers and wildlife enthusiasts, its aim is to give users a fascinating insight into the natural world while also enhancing their digital making skills. To this end, it comes in kit form, although no soldering is required. It takes an hour or so to put together, following the detailed online PDF instructions. The latter are well-illustrated with plenty of photos, even if a couple were slightly misleading.
Constructing your camera
A laser-cut plastic insert is provided to suit whichever Raspberry Pi model you’re using; the standard kit comes with an A+ due to its lower power usage, but it could even be used with a new Pi Zero v1.3. Screws and plastic spacers are supplied to fit most of the components – including PIR sensor, Camera Module, and Pi – to the insert, threading jumper wires through its strategically placed holes. It’s clear that much thought has gone into its design; you even get bendy ties to push through pairs of holes to secure the wires tidily. Still, it wasn’t so easy to fit the jumper wires to the Pi’s GPIO pins through the large cut-out, requiring a small screwdriver to push them into place. A real-time clock module is also fitted to five of the pins (since the Pi doesn’t have one built-in), to enable accurate date/time-stamping of photos without an internet connection.
Finally, an Adafruit Powerboost is fitted to the insert and connected to a LiPo battery. This is to boost the latter’s 3.7V output to the 5.2V needed to power the Pi and other components. A power switch has been added to the Powerboost to make it easier to switch the camera on and off when outdoors. Before you can use it, however, you’ll need to charge up the battery, which takes around 17.5 hours; it might be advisable to start doing this before assembling the rest of the kit. Naturebytes claims it will provide around 30 hours of power; in our tests it lasted up to three days between charges.
Testing it out
Before positioning the camera trap outdoors, it’s a good idea to hook it up to a TV to check everything’s working properly. The supplied SD card features a customised version of the Raspbian operating system, featuring a Naturebytes logo and desktop shortcuts for various tools, including PIR and camera tests. The main Python script for taking photos can also be tweaked. By default, it adds graphical overlays – a date/time stamp and Naturebytes logo – to each photo taken. However, we found that this was causing a lengthy delay (of up to two minutes) when writing to the supplied USB stick, possibly caused by a lack of RAM in the 256MB Pi A+ to handle the I/O process. Naturally, this is undesirable when capturing wildlife photos, as the critter may have vanished in the meantime. Fortunately, commenting out the code lines for the overlays solved the problem. Writing to an SD card is even quicker, although it’s far more convenient to simply remove the USB stick and plug it into another PC in the house to view the photos, without having to bring the whole device back inside.
Venturing outdoors, a Velcro strap is used to fasten the Wildlife Cam to a tree or fence post. The green acrylic case itself seems very tough and durable and snaps tightly shut, secured by two plastic clamps. Naturebytes has tested it in all weather conditions, and we experienced no leakage whatsoever following a downpour. On the front, a circle of clear plastic protects the Camera Module, while another translucent cover guards the PIR sensor.
Start snapping
Once in position, toggling the Powerboost switch turns on the camera and the picture-taking Python script will start running automatically. Our first attempt yielded a shot of a wood pigeon in flight, plus numerous photos of nothing: false positives triggered by the changing amount of sunlight. This effect can be reduced by repositioning the camera to avoid morning or afternoon glare, or by adjusting the sensitivity of the PIR. You can lure wildlife in front of the camera trap by placing it next to a bird table – we improvised by pouring some seeds onto an old garden table and managed to obtain a great shot of a magpie! There’s also an optional wooden arm to hang a bird-feeder in front of the camera.
Whatever tactic you use, viewing the photos at the end of the day is an exciting prospect, just to see what has been captured. While not ready at the time of writing, Naturebytes is also working on an online community hub where users can share their wildlife photos, which should add an extra dimension to the project. Ideal for educational use, the Cam Kit is also quite versatile and could be used for time-lapse photography, night-time shots (with a Pi NoIR camera and IR LED lighting), or even a live video feed.
Last word
4/5
While more expensive than originally envisioned, the Wildlife Cam Kit is easy enough to assemble and fun to use. Once we’d sorted out the photo-taking delay issue, it worked well outdoors and the anticipation of seeing what it had captured was exciting. That lengthy battery recharge time is a little annoying, but it does power the unit for quite a while. Most importantly, the weatherproof case is very robust and may soon also be available as a standalone unit.
