hi again, like i said before, i was looking for cheap rf transmitter and reciever, and i think i found one, but i just need to make sure i can use it!
please tell me if i can use this with only 1 arduino, becuase i dont think 2 are really neccasery...
here it is:
they look pretty good, but can i use them with 1 arduino? can i use the reciever with lets say a shift register or an led serial connection? what can i connect the reciever or transmitter to thats cheaper then another arduino, becuase i want to place my order tonight, and i want to get this to me by next week hopefully!
Those modules will not work directly with a serial port. They require use of manchester encoding, which ensures the line is always changing (even when sending a bunch of repeated bits)
I haven't taken a crack at this one yet, and I don't know how easy it would be to make an arduino use this encoding.
Another option is using a separate encoder/decoder, these work similar to keyfobs in that, when one of the input pins goes high, it transmits the corresponding pin, which in turn activates on the decoder attached to the receiver. This of course won't be good for sending complex data.
Hello again,
First off, these forums do not have a very good search engine.
Secondly, I'm taking a crack at using arduinos with these transmitters & receivers using manchester encoding. Since there is another thread inquiring about development of a library, I'll add my findings there.
Yes, of course there is google. But having a 'search' button and search feature built into the forum software gives one the impression that it should be put to use. Also, many people do not know of specific search engine features ("site:"), or do not look further than the built-in search (or some not searching at all thus the acronym "UTSE"). Someone should fix that.
I'm having issues with the RF links. Currently each bit takes up 416 microseconds. So a string of 0's produces oscillations at, 208mics high, 208 low.
But as you can see, my 2400bps link is not outputting as expected. Both units have antennae, and are within close proximity. What is happening is "low" is being high for twice as long as it is "high". This is causing my receiving code to fail. If anyone could shed some light on the issue please do so.
On sending and receiving side, the data pins are connected directly to the respective arduino's data pins. On the receiving end if there are two pins marked "data" use the one closest to the edge of the device.
Note: I'm using 4800bps modules. The timing on the sending side should be halved for 2400bps modules.