Hi. I'm working on a project which involves eight Nanos communicating two way with a ninth master unit. The master polls each of the slaves in turn, which immediately reply with a small string of data which the master processes and updates other slaves accordingly. I'm using the cheap 315MHz eBay RF units and VirtualWire.
Initial tests using one-way communication gave me very reliable data transfer over a range much greater than required for my final project. However, now I have multiple devices at play and transmissions going both ways, my range and reliability has dropped significantly. Even when the units are only a 2-3 meters apart and in clear sight of each other, I can lose most of my broadcasts.
My question is this: do the TX modules create background noise when powered up but not broadcasting? Is it possible that several powered TX units in a confined space are creating a wall of background noise that the real signal is struggling to get through?
Should I power the TX unit from a pin, so I can switch it off when it's not broadcasting?