RF 433 and 315 two way communication - weak signal

Hi All,

I've been playing with two Arduino and two transmitter/receiver pairs, one at 433Mhz the other at 315Mhz. These modules are VERY cheap, which is fine since I am only learning/experimenting.

I've used VirtualWire to get the two Arduino successfully talking to one another but the range is terrible, maybe a few centimeters at most. I've tried a range of different antenna lengths (just a straight piece of wire) based on various bits of information I've managed to find through Google and searches on these forums but it doesn't appear to make a great deal of difference.

I just wondered if anyone had any clues on what's happening. Is it possible the two pairs are interfering with each other? If I use just one transmitter/receiver the range is better...sometimes with a stable two way connection over a few meters and/or between rooms. Maybe it's because the modules are cheap?

Any advise appreciated.

Cheers, LongTom

433 MHz - need 17cm antenna wire. 315 MHz - need 23cm I think.

Are both transmitters going at the same time? Could be messing up your data. Make sure each end finishes receiving before it starts transmitting.

CrossRoads: 433 MHz - need 17cm antenna wire. 315 MHz - need 23cm I think.

Are both transmitters going at the same time? Could be messing up your data. Make sure each end finishes receiving before it starts transmitting.

Hi Crossroads. You are one of the people whose previous posts I've seen related to RF coms. Thanks for posting here too!

I had 17cm antenna for both 433 and 315 modules so I will try with 23cm on the 315MHz to see what I get. I only transmit one way at a time and never at the same time but either end sends very quickly after receiving...so I don't know...

Yeah, I'm kinda all over the place. I've used a 433 MHz Tx/Rx pair in a remote control, Tx powered by LiPo. Range is at least 50 feet (length of my fencing club) using just 30 guage wire wrap wire for an antenna on both ends inside plastic enclosure. Rx is 5V powered. Maybe the modules are just a little too cheap, and not quite in tune?