Oxford Real Farming Conference 2015 – making a remote farm camera

This is a description of how to make a remote farm camera. Smallholders don’t always live on site, or you may have an island site somewhere without power. The simplest solution to get pictures from a remote site without power is to use a 3G trail camera and these work very well for tracking wildlife.

The trouble with this solution on a farm is that animals are meant to be on a farm all the time, Trail cameras look for warm-blooded critters so mammals and birds will set it off all the time, making this an expensive operation in MMS messages, which seems to be the preferred method. Even if you get a MMS bundle, trawling through the false alarms will bore you.

What we wanted of a remote farm camera

was to be able to check on how things were going, and whether something has been damaged by stormy weather. A CCTV camera on the farm would be fine, but the problem with this is the power drain, and getting the pictures back. If we had mains power this would be a lot easier, we could use a 3G CCTV DVR with remote access capability. You can easily get 12V CCTV gear, but the power drain of a typical DVR and camera is quite harsh – typically 1A or more. A typical leisure battery is 80Ah, but you should only use half of the capacity of a lead-acid battery that to avoid reducing the service life of the battery, and you must never fully discharge it. This gives you a battery life of less than two days.

Our remote farm camera uses a Raspberry Pi Model A and associated camera to take a picture every 15 minutes in the daytime and upload it to a website

Simplest solution involving very little assembly

Use the original alpha-test camera version. Run a MiFi box using a 3G dongle and connect the Raspberry Pi using WiFi. It’s important to make sure the 3G dongle and the MiFi box will work together, then use a suitable 3G plan. I use GiffGaff

because their 1Gb/month offer is okay for two cameras  -you will probably get away with the 500Gb for £5 version with a single camera.

You can power the MiFi/dongle and the Raspberry Pi off aavailable from ebay.

Running this outdoors

12V is safe outdoors, and is widely used for fence energisers etc, but you must use a 5A fuse in line with the battery for fire safety reasons. You can mount the MiFi and dongle in an enclosed box – if you can make this watertight using bathroom sealant etc then use some silica gel to stop the damp.

I take the other approach adopted by the now defunct PICE Raspberry Pi case – water drains down. My timer/controller (similar to the job the the MiFi box does) is in a plastic non-watertight box with a cut-down plastic water bottle over it to keep the rain off, and I raise this a couple of feet off the ground to keep away from splashback. The camera construction is in a plastic box, with connectors underneath. I use a neoprene cover as a sun and rain-shield.

To get a decent field of view to cover a few pigs you must raise the camera higher up than normal. Unfortunately the force of the wind increases with height too, hence the paving slab.

This draws about 250mA at 12V, giving a battery life[ref]80Ah÷2÷0.25≅160, there are 168 hours in a week[/ref] of about a week.

If you have mains power on site use a CCTV DVR

Use athat supports mobile, either via broadband on using a MiFi device as a WiFi hotspot in the same way as the MR3220 is used here. Job done. You can then check on your farm via the web using your mobile or tablet using the DVR app.