Decoding the LightwaveRF LW600 Energy Monitor

[Benet Allen]

I’ve been trying  (with the help of Claude, but for several days) to decode radio transmissions like this:

{"time" : "2026-03-06 14:07:27", "model" : "MC", "count" : 1, "num_rows" : 1, "rows" : [{"len" : 138, "data" : "55555977d8a7b9131bdadb81032136ffe48"}], "codes" : ["{138}55555977d8a7b9131bdadb81032136ffe48"]}

My home energy project is a solar-battery-multiple property setup, and although my inverters monitor the overall load, I would love to re-purpose my old-school LightwaveRF kit, which includes six energy monitors and two hubs. 

I’ve got RTL software radio and node-red on my Mac.  I’m not a software engineer by training - I don’t speak Javascript (or Python for that matter) but Claude and Gemini have been a great help.  I *could* buy another four hubs on eBay, but that seems kludgy.   Can anyone help me understand the radio signals emitted by the old Energy Monitors?

Many thanks,

Benet Allen

Minehead

[Christian Z.]

First get a sample file and check if the timing and modulation is correct. (MC could be DMC.) Or upload a sample file and let others have a look.

Then table what you seen on some display with codes and compare. Maybe in a https://triq.org/bitbench/

[Benet Allen]

With pleasure.  Thank you Christian for jumping in!  

[Christian Z.]

The sample file we need to look at would be .cu8 -- see https://triq.org/rtl_433/ANALYZE.html

Inspecting the spectrogram (https://triq.org/pdv) should be a fun way to get a feel for what such a rf signal is.

[Benet Allen]

Hi Christian.  You probably gathered, I'm new to this. I thought the problem was decoding data bursts, but perhaps it's actually seeing them?

frequency 868.35M

sample_rate 1000k

gain 40

protocol +61

https://drive.google.com/open?id=1rxdCKrMFGadU002EPRD-XIULJibOCbwX&usp=drive_fs

[Christian Z.]

That upload ist protected, probably needs to be set to public read access.

[Christian Z.]

The strongest signal, 3x at 6.5 and 2x at 13.5 s, is FSK but not MC. Some of the other signals look similar.
You need to isolate the signal you are interested in. Maybe use -S all

[Benet Allen]

Thank you Christian.  I was hoping to read six sensors.  I'm afraid I shelved this project in favour of simply buying a whole batch of LightwaveRF hubs, one per sensor, obsolete and cheap on eBay. 

[Christian Z.]

Thanks for the update. Dedicated RF receivers are way more efficient than an SDR. Your solution is a good one.