Have a really good idea for a project - I (will) have 4 arduinos 1 master reciever and 3 slaves which need to communicate over RF, maximum of 100ft range.
There is no high speed data communication required so 2400bps would be plenty, needs to be quite a cost focus on the project but the sparkfun jobs below look quite good.
The only challenge I have is (I think) which slave is sending the data - my guess would be to send an initial string to the the master which identifies which slave it is?
Any input would be greatly appreciated - as would a UK supplier for something like the sparkfun modules linked!
Having the master poll the slaves, requires recievers in each of the slaves which will start making it more pricey - need to do the sums to work out if it will be too pricey.
Do they do 433 TX/RX combined units?
The chance of more than 1 slave sending data at one time is pretty slim - interesting problem though.
Didn't realize you were looking at transmit only on the slaves. (Guess I should have looked at the link!)
Without a receiver you will have no way to even tell if the data collided with another slave & retransmit.
The only other way I can think of to handle it would be to have the slaves transmit on a schedule. However, if there is any drift in the timing, you'll end up colliding all of the time.
there is a guy on ebay which sells dr3100's which he brings back from austrilia. they're tranciever modules. 100 ft might be pushing it a bit, but he does provide a hint on how to increase the range above leagal limits! they cost around £5. i'll find his ebay username out when i'm at home.
there is a guy whos written a library for this and other 433 rf units. its on the play ground some where, but i havn't actually tried it yet!
ps sorry it this is a bit illedgable, but i've written it on my phone!