Intermittent Dropouts Observed at 4 feet with XBEE Pro Serie

Wireless & IoT
1

My project uses a pair of XBEE Pro Series-1 modules. One sends serial data at 115200 baud and the other receives. Data string is 20 ascii characters.

For troubleshooting purposes, the modules are only 4 feet apart. All functions correctly, but if I cover one of the XBEE modules with my hand without touching any parts, I get intermittent data dropouts (meaning the receiver fails to receive data). If I move away my hand, all functions normally. The spec for range states 300 feet indoor, 1 mile outdoor.

Could a degradation in XBEE performance be caused by my wireless router and/or Apple TV devices (3 total)?

Any XBEE setting or other tip to prevent or reduce these dropouts?

2

Which Xbee models? Part numbers please. The kind of antenna and RF frequency band makes quite a lot of difference.

Any XBEE setting or other tip to prevent or reduce these dropouts?

In general, there is a powerlevel AT-command. Read the datasheet/manual how to operate the Xbee.

P.S. Placing them too close together can also negatively affect reception reliability.

3

Human beings are pretty opaque at 900 MHz, so it could be an issue of blocking the signal, even with a hand - due to the wavelength the spacing between your fingers can look like a solid object.

Another issue that can come up is that your hand/body being near the antenna can actually de-tune it away from the desired operating frequency so it is not only blocked, but is also much less efficient at radiating the desired frequency - you don’t have to touch it to de-tune it, just getting within a quarter wavelength ~10cm is enough.