Arduino + RFM12B

Wireless & IoT
1

Hello all, so I just got two RFM12B’s and am trying to get them to communicate but have run into so many problems I am about to toss them. I tested each pin with my volt meter. All pins on each arduino have the same volt except the antenna pins. One has .015v the other .005v.

I am running the pingPong example on each arduino. My problem is they are sitting right next to each other and they only get about one in ten signals being sent. When I move them further apart the reception goes down to zero. The crazy thing is this is a new problem. When I first got them communicating every packet went through fine. I am using a piece of wire as an antenna and have experimented with a few different shapes and materials I had lying around, the antenna does not seem to make any difference in the amount of crc errors. If I skip the crc test I see the data I am trying to send but it almost always has some little error in it.

As you can see I am very confused and don’t even know what to do next to narrow down this issue. Please any advise would be great.

2

I have those radios working fine.

But I’m an RF guy by trade, and experienced in microprocessor work.

I don’t think that SFE sells these (wish they did), but I began with these modules, also based on Atmel AVRs and can take the Arduino bootloader via USB, etc.

http://jeelabs.net/projects/hardware/wiki/ is the designer.

The modules are sold in the US by a company I won’t mention here - may be an SFE competitor.

I learned the modules, reading the data sheet, experimenting with the demo code. Then I moved on to my own protocols and code.

As to the CRC errors - there should be virtually none at close range. I ran mine with 6" wire for 500 ft. or more, from inside house down the street, at a low error rate.

Mine are 900MHz, not 433.

You might try setting both to use a different frequency if there’s persistent interference.