Greeting to the Arduino community, while I've played with electronics off and on throughout my life, I just got my first Arduino and love the simplicty and familiarity of the programing language! I never did figure out assembler... ;)
I am considering a project in which I'd like to build a beacon and a receiver. Problem is I'm not really sure where to start when it comes to antennas and radios. Probably should have taken that HAM Operator course last fall... ;)
The basic concept is to be able to identify how far away (signal strength) the transmitter is. The receiver can then go into alarm mode if the transmitter wanders too far away. Purposes abound... Kids too far from home, dog ran away, your previous safe just got stolen when the quests left... you get the picture. The distance I was hoping to achieve was upwards of 2 kms (or 1.5 miles) with the ability to reduce that range within software.
Most wireless solutions I've seen are based of some kind of bi directional data communication and this isn't quite what I had in mind. Maybe the transmitter could send an almost morse code at set intervals to identify itself and allow for multiple transmitters but not looking to send "data" as in temperature or device status etc. While the standard "wireless" shields / attachments are based on this data concept, they are also limited in range to around 100-300 meters.
Has anyone seen any projects similar to what I am talking about? If so can you give me a few keywords as I am not having the greatest luck with my searches.
PS I did order some 2.4ghz transceivers even though they have limited range to begin playing with the concept...