Which technique / component to use, to send a simple sequence (like 'A', 'B' or 'C') from a remote device to Olimexino board, over radio signal, over 200 to 500 meters distance?
Olinuxino receiver is installed on the field, in area without GSM/3G network. Once a week it is powered up and shall receive the command from the remote unit, which can be also Olinuxino.
Which components to use to establish such link? Zigbee range seem to be around 100 m, to short and not found 433 MHz modules for Olimex, which should work up to 1 km I suppose?
Any reccomendations?
there are msny things to consider with using RF.
things like RC or zigbee in the USA is run under FCC Chapter 15 and limits distance.
Once you exceed that limits you must use commercial RF Radios.
This holds also for using a 15db Yagi folded dipole direction antenna that would extend the range of low ppower RF modules.