Ok i want to build a closure logger. its basically a telescopic tube that is pinned between a roof and the floor. When the roof moves down this devices measures the amount the roof has moved down relative to the floor. the way this device works is not so important right now but what is important is that i need to record this data over a few months, maybe store it on a memory card on the device. Then i must retrieve this data from a safe distance, so i will need to transmit it wirelessly. it must be done wirelessly from approximately 15meters or so. I want to use a stand alone arduino atmega328 microcontroller in the unit that measures the movement and i will also want to use a atmega328 in the unit that receives the data.
The picture bellow is a real basic concept of what i want to do. For example once the device has been in place and it has recorded movement over months i want to go in the approximate range and push a button basically then the device must send all the data it has recorded over the months to the remote unit which can then save the data on a memory card and analysed on a computer.
i am asking for help regarding the data transmission, i do not know how to even begin. i know nothing about what hardware i will need, i know nothing about wireless serial communication. Can someone please nudge me in the right direction as i would like to not waste time researching on the incorrect stuff.