I love my cats 
Therefore I would love to see where they are when I need them. I could by a GPS for cats but there’s no fun in that, is it? I would like to build one myself. It should be small, as cheap as possible, able to transmit data at least every fifth minute and battery should last for 24 hours. How do I accomplish this? What hardware should I use?
Please give me some ideas where to start and what hardware to use. How small can I make this and what would the cost be?
How far away would the cats be?
I don't know :) I let him out from my backdoor but I don't know how far he walks.Joeisi:
How far away would the cats be?
How big is your cat and what is the weight?
The lightest professional systems that can be bought easily are about 70 to 80 grams. That me be OK for a large dog but will be too heavy for a cat.
The battery alone will be about 1200 to 2000mAH so you are looking at about 40 grams for battery alone
There was a similar question [here. I believe he ended up using an openlog + GPS.](http://forum.sparkfun.com/viewtopic.php?f=14&t=32695&p=145824)
This is what I was afraid of. That it will be to heavy.
Yes, an alternative is to log the data on the device and transfer it to my computer via USB or something. What do I need to make such a device? Openlog, GPS, a memorycard, battery and USB? Any adaptor card that would be neat for such thing?
I would just suggest recording the data in FAT and transferring it directly to your computer. No reason fumbling with USB. I know both Arduino and Microchip have FAT libraries. So basically all you need is a battery, uC, GPS,and uSD card. Remember: SMT is your friend! With the battery you may want to use a switching regulator to conserve power.