Wednesday 30 January 2013

Raspberry Pi down the Garden

I'm now installed a Raspberry Pi with two webcams at the bottom of the garden using passive power over ethernet with a 40m cable. In the autumn I tested this indoors to catch invading mice, but now the snow has gone and spring seems to be on its way...

Raspberry Pi, passive POE, and DC voltage step-down squeezed in a box

The water-tight box I selected in store at my local Maplins was their light grey 125mm x 100mm x 60mm project box (code N25HG RL6335-F). In store this seemed quite roomy for a little Raspberry Pi, with space for my passive POE adaptor and 24V to 5V DC stepdown module. However, I'd forgotten just how long the USB plugs were, and it is actually  quite a tight fit.

The two bright blue spiky things are a couple of aluminium passive heatsinks - which seemed a sensible and inexpensive precaution as this will be running inside a sealed box.

You might also notice in the photo I did the USB port polyfuse by-pass (using telephone extension wire), which should help powering hungry USB devices from the RPi. I'm not sure if it made any difference for my webcams - even with their extra infra-red LEDs.

For the cabling I was initially hoping to use a cabling gland for a nice water-tight seal, but none of those in stock would allow a USB or ethernet plug though (the cable thickness would have been fine). Instead I cut a notch just big enough for two USB cables and my ethernet cable - which will go at the bottom of the box once mounted - perhaps I can add a little hot glue or sealant?

DIY shelter for my Pi in-a-box in the garden

My original plan was to place the Raspberry Pi near Birdbox III (initially occupied by blue tits, displaced by sparrows, and then left empty) with a direct USB connection, and use a 5m USB repeater cable to connect it to Birdbox IV (intended for woodpeckers, but used by sparrows this summer) as well. Sadly in my field trial the USB repeater cable wouldn't work with the RPi, so instead the second camera is monitoring a compost heap (which I know mice visit).

Birdbox III is occupied! Compost-Cam: cherry tomatoes and potato peelings! 

I'll be using Motion to capture images, these were just saved via the Motion webcam feature - I wasn't actually expecting anyone to be in the bird box.

Update (2 Feb)

The roosting ball of fluff is a Blue Tit, and it seems to be a regular house guest overnight. The compost-cam has confirmed there are regular mouse visits to the compost heap:

Roosting Blue TitMouse in the compost heap

There is potential bad news for the Blue Tit - during the day there has been a Sparrow visiting too, perhaps also eyeing up this as a future nest site? Last year a Blue Tit pair was pushed out of this bird box by sparrows...

What's that ceiling fixture?Twiggy

Update (8 Feb 2013):

I've switched the bird-box's metal entrance plate to a smaller Blue Tit sized one to try and keep the sparrows out - there are several other birdboxes in the garden they can use and this year I'm hoping that Blue Tits will nest here. So far just one Blue Tit is using this as a nightly roost box.

Update (March 2013):

After filming mice in the compost heap, I've replaced that camera with a Raspbery Pi powered trail camera.

Update (29 May 2013):

The Blue Tits have laid a clutch of seven eggs.

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