XBee's found in TXU Energy iThermostat

Wireless & IoT
1

I’ve been wanting to grab some XBee’s for a while but could never justify the cost. Yesterday I was digging through some old electronics parts and as I was throwing away this old TXU thermostat… holy cow! An Xbee with a wire attena! So I quickly grab the other piece of the thermostat and sure enough was an RPSMC Xbee, antenna and all. After I stopped dancing I grabbed the soldering iron and went to work making a temporary socket for them.

The problem is, I can’t communicate with it. I don’t have an FTDI cable or a USB explorer or anything, just my Arduinos (an uno and a duemilanova.)

I’m using linux (Arch, 64 bit) and have tried communicating with it using puppy but no matter what baud rate i’ve tried I have not been able to get any response to the ‘xxx’ command, or any command for that matter. Upon powering up the xbee both the LEDs (pins 13 and 15 on the xbee) are solid. I’m assuming that TXU installed some awkward firmware to it but to be honest I don’t know enough about XBee’s to clarify that conclusion. So I have a few questions…

Is there any way to determine what baud rate an Xbee is set to?

Is there any way to connect it to USB for a firmware upgrade using only an arduino uno or duemilanova?

Is anybody familiar with the settings the XBees for TXU use?

Am I even doing this right??? :stuck_out_tongue:

Thank you in advance for your help! I have read books and blogs galore with no luck with these questions and any help would be greatly appreciated!

2

No idea on the TXU XBee but Digi has a few products with XBees in them that have the serial IO port disabled by the firmware. The word is that these XBees will not accept a new firmware download using the serial lines.

XBees do have a programming header pads but that requires special hardware.

Maybe a call to Digi’s tech support would help.

3

I’d think Digi would be reluctant to help someone reverse engineer an OEM’s use of their product.

4

My suggestion was NOT to reverse engineer but to find a way to load new Firmware that would turn OP’s XBees back into running a standard Protocol like 802.15.4.

I just remembered a method to load firmware into an XBee that has the Serial lines disabled. Just follow the procedure to recover a ‘bricked’ XBee. Google here to find the instructions. You will need a button/switch on the XBee’s RESET line.