I wanted to connect FEZ Cobra with FEZ Domino using XBee. I bought XBee shields from GHI. Those shields are designed to work with Digi XBee modules (former MaxStream). First problem is that Digi offers a whole variety of modules which are divided into:
- Point to Point & Point to Multipoint (P2P & P2M)
I have no knowledge about industrial wireless technologies but as I read I found out that the first kind (P2P and P2M) uses 802.15.4 protocol and second kind (ZigBee/Mesh) is the actual ZigBee technology that is build on top of 802.15.4. For my first demo project I wanted only to connect two devices so I have chosen:
This is a P2P/P2M module with on-chip antenna. I set up my demo by connecting each module to each board. FEZ Domino was programmed to increment int counter and send its value every second, and FEZ Cobra was programmed to receive the data and display it on the screen. Both boards were laying next to each other. I have encountered two problems:
Each board was connected to my PC with its own USB cable. This caused some data loss (Cobra displayed e.g. 10, 12, 16, 19). After I unplugged FEZ Domino from PC and plugged it into FEZ Cobra USB Host port everything works with no problem. Is this some GROUND issue ?
I have performed a range test by connecting the FEZ Domino board to a laptop and trying to determine how far can I go with it (line of sight). I wasn’t able to reach more than 5 m because nothing was being displayed on Cobra! Datasheet tells me that this module should be able to work within 30 m range indoors !
I would be grateful for some tips from those that have some XBee experience