So, I'm starting off by doing the whole hardware part, which is very simple. I can always work on the software further down the line, as long as the hardware is already correctly defined.

I intend to use my system in two different ways for now:

• As a small "modem", in the 433MHz band. The idea is to be able to communicate, transfer files between two computers, without any internet connection. Bluetooth is a technology that is able to do that sort of thing, but usually only up to 10-100m, in the 2.4GHz band. By using a lower frequency, attenuation will be lower, thus increasing the range for the same power used. Furthermore, if you have an amateur radio license, it's easier (and cheaper) to buy/build a power amplifier for the 433MHz band than for the 2.4GHz band.
• As a pager system. It's still not clearly defined, more to come in the following logs.

Both should be able to be implemented with the same hardware:

• Some sort of 8-bit µcontroler (I'll stick with ATMega328 for now);
• RF module (I'll use first those cheapo CC1101 you can buy on eBay for 5 bucks, I don't want to do any RF PCBs for now);
• Display/buttons;
• Optional Power Amplifier.

So first thing that has to be done is the Main Board, which will include the 3 first points. The power amplifier will be designed later on.