Buzby
Senior Member
A combination of ultrasonics, low power radio, and clever software ....
http://www.robotshop.com/uk/indoor-navigation-positioning-system-starter-set-case-915mhz.html?utm_source=Facebook&utm_medium=Paid&utm_campaign=ProdCatUK
http://www.robotshop.com/uk/indoor-navigation-positioning-system-starter-set-case-915mhz.html?utm_source=Facebook&utm_medium=Paid&utm_campaign=ProdCatUK