Hey, I'm trying to make a custom controller for my quadcopter. I'd like to use a radio system that I can control digitally (i.e. send bytes) like Bluetooth, but I'm looking for something longer range, like maybe 1km. Is this asking for too much? All the radio systems I can find are the traditional channel systems. If anyone could point me in the right direction, I'd be grateful.
A really easy to use RX/TX system to use are XBees.
The only downside to these is that they can get a little expensive if you're on a budget. This is the easiest way to do what you want in my opinion. Some modules can even get up to ~28 miles LOS if that's what you're looking for.
You may be interested in the nRF24L01+ 2.4GHz transceivers. They work very well and are cheap. The low power versions have PCB antennas and there are high powered versions with an external antenna. I suspect you could but one with the PCB antenna into the 'copter and use one of the high-power versions for your hand controller.
This Simple nRF24L01+ Tutorial will help get you started if you want to try them.
This Youtube video shows them working at long range. However I have no personal experience of the high-power version. I am only using them to control model trains
Another possibility is the HC-12 433MHz module mentioned in this Thread. Again, I have no personal experience of it. I suspect that the nRF24 system is more secure - but I could easily be wrong.