My priority for the GPS module is the size and antenna. I’ve worked with external GPS chip antennas in the past and they can be a nightmare! Therefore for this project I’m after a small GPS module with an integrated antenna.
We’re having a bit of a heat-wave at the minute in the UK! It has been over 30°C (86°F) for 2 days in a row. We can’t cope. It’s too hot. Buttons particularly is not impressed. The coolest place he’s found is on top of the water butt – as you can see in the picture.
Anyway, as everyone knows, the best thing to do when it’s nice and sunny outside is sit inside on a computer and look at Microcontrollers.
There are going to be three main elements to the CatTrack design:
- The microcontroller
- The narrow-band transceiver
- The GPS module
I’ve pretty much ruled out any kind of design that requires a continuous connection via cellular modem.
The advantage of a continuous cellular connection is that I would be able to remotely send a query to the collar (either via SMS or a data connection) and get it to report its location back to me, from anywhere in the world.
The simple answer is battery life.
My requirements for a cat tracker are:
- Very long battery life (around 3 months). I don’t want to be changing batteries all the time. The one day I forget to change the battery will be the day when Buttons decides to go an investigate next door’s shed, I know it.
- GPS-level accuracy.
- The ability to remotely find out where your cat currently is, allowing you to find him if he’s lost.
- Small enough and light enough for a cat to carry around (obviously!).