Lawn Defender Continued


Earlier this year I met with Vernon Funnell who introduced me to his technology prototype to deter pets from lawns . Today I met with Vernon again who presented the new upgraded version of Lawn Defender in a swish new black box.

How do I use the box?

The box works by initially turning the device on through the red button on the side of the box. This runs the Linux script over the initial 2 minute set-up period on the rasberryPi. After this period the blue button (dubbed ‘arming button’) is pressed which starts the Linux loop and arms the PIR sensor to wait for input. Once input has been received, a picture is taken through the camera which is then outputted to his twitter page.

So what’s new?

The box has been upgraded into a sturdier black plastic case with parts being weatherproof (such as the light). The components have also been glued in making the component less fragile. He has also built his own spring loaded lid to allow the box to be opened effortlessly with a touch of an embedded button.


Vernon did state that the PIR sensor needs some tweaking in regards to the luminosity, as it can go off from the light initially and also is not yet fully weatherproof. He has also tested the device on some dogs and cats. The dogs and cats reportedly did not seem to mind the flashing lights or sounds currently installed but these can be modified with some trial and error to reach his initial goal of scaring away pets.

Dr Nick Mitchell also saw the Lawn Defender device and suggested a water gun style arm to scare away pets from the garden.

The future of lawn defender?

More recently Vernon left the device in his garden with some bread crumbs on the table and captured a lovely picture of a bird feeding (below) which he saw while he was at work thanks to the twitter upload. This led us to talk about the other uses of this device.

We also had a discussion about using the camera to detect and label the animals it finds. An example of this could be Lawn Defender detecting the animal, recognising them and then informing the owner of where they are. While it would be simple enough to do on colour recognition e.g. a black cat from a white cat, as soon as you introduce two animals with similar colouring their needs a more complex method.

This technique goes over into Claire Micklins work she presented in AHCI back in November, on making a dog tracker to trace stray dogs through RFID tags. Although you would not want to chip other people’s animals, the idea of a machine to read the already often present chip tags within most pets is an interesting concept but would only work with owned chipped pets and not strays like in her work.


The Lawn Defenders key attributes are still its ability to pick up movement from the PIR sensor, capture the image through the camera sending it to an online media form. The design also could arm a number of different factors (e.g. water gun, nerf gun etc.). This device both enriches Vernon’s own use of his garden, his friends and neighbours and the community through the knowledge stored in projects like these. It would be lovely to see a video on the specifics of how Vernon made the Lawn Defender, and a fritzing sketch for future developers facing the same path.

I am currently undertaking a side project using Arduino and the online community has proven invaluable in both information sharing (videos, sketches etc.) and problem solving. By sharing online this also gives other developers a platform in which to progress from and lets your ideas grow in a whole new direction.

Link to Vernon’s Lawn Defender Twitter:

Demo of Vernon’s Lawn Defender:

Written by Ilyena Hirskyj-Douglas on 16th June 2015 

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