I have a two XBee pro 900hp 10Kb point-to-multipoint xbees.
I have each xbee connected to a separate computer through two parallax usb adaptor boards (32400, Rev C).
Whenever I send a frame from one device to the other through XCTU, the maximum RSSI on the received frame, is always -40db.
I thought the antennas might be the issue, so I swapped them out, but got the same results.
My next diagnosis was power. I tried sending the packets with different firmware assigned power levels, but again -40db was the best reported rssi.
I swapped out the 900hp modules with some series 1 (non-pro) modules.
I believe the series 1 modules have 1mw transmission power, vs the 900hp’s 250mw tx power.
In XCTU I performed the same experiment as above. The RSSIs I saw had much better values. The best I saw was -26db.
Anyone have any advice?
For now, my next test is to hook up a volt meter to the power and ground pins of a 900hp module and see if there is a significant voltage drop upon transmission. my diagnosis from this behavior would be that I’m not supplying enough current to the module.