Hey All,
I am looking to receive and process the data from my OWL CMR119 wireless power meter.
Using an Uno hooked up with a XY-MK-5V 433MHz receiver I am able to get a steady stream of data in what appears to be Oregon Scientific V3 format, the output looks like this :-
OSV3 1A00343D0020990B0000
OSV3 1A00343D0070A30B0000
OSV3 1A00343D00C0AD0B0000
OSV3 1A00343D0010B80B0000
The first character is the channel, this changes from 1 to 3 if I change the channel on the transmitter unit, the A always remains the same and the next two characters are a bit random, but if I force an update by holding the check button down on the transmitter these two characters form a countdown, this is 100% repeatable.
Now decoding the rest is where the fun begins, I thought I had it at one point where a calculation matched what I was seeing on the CMR119 display unit, the issue then arose where I increased the monitored current and the calculation broke down.
I believe the transmitter module and clamp are only monitoring amps, sadly the display unit doesn't have an option to display amps, I was using a separate meter alongside the Owl to check / confirm amp usage.
With a 0.3A load I was able to see a 3 in the datastream that drops to zero when the load is removed, this again is 100% repeatable, the issue is when the load is increased to something else the values no longer match.
Using the below calculation I was able to take the 0.3A figure and arrive at the same displayed kW on the CMR119 display unit :-
pF x A x V / 1000 = kW
0.7 x 0.3 x 240 / 1000 = 0.0504
The display unit only has voltage options for 110,230,240 and 250, hence me using 240.
Anyone have any further information on these units that might help?