Optex 990051 #2375
Description
I've an Optex 990051, the little brother of the Optex 990040 (which is the Emax EM3390W6 under the hood).
It is correctly recognized as an Emax weather station as the protocol is almost the same, everything is decoded correctly except UV and Lux sensor, as it doesn't have any! Also the internal reference, according to the documentation, is EM3551H-DCF.
Here is some decoded data:
model : Emax-W6
id : dde
Channel : 4
Battery_OK: 1
Temperature_F: 16.7
Humidity : 33
Wind avg speed: 0.0 km/h
Wind Direction: 99
Total rainfall: 60.2 mm
UV Index : 15
Lux : 0
Integrity : CHECKSUM
And here is some raw data:
ffff8000aaaaaaaaaacaca54aa04c52b064c34010101d4019e4001010004050607080910111213141516ec74ed0000
ffff8000aaaaaaaaaacaca54aa04c52b064c34010101d4019e400101000405060708091011121314151662ea630000
ffff8000aaaaaaaaaacaca54aa04c52b065348010101d4019e400101000405060708091011121314151613b6140000
ffff8000aaaaaaaaaacaca54aa04c52b065133010101d3019e40010100040506070809101112131415163ac53b0000
ffff8000aaaaaaaaaacaca54aa04c52b064e33010101ca019e40010100040506070809101112131415169c1b9d0000
ffff8000aaaaaaaaaacaca54aa04c52b065034010101cb019e40010100040506070809101112131415161194120000
ffff8000aaaaaaaaaacaca54aa04c52b065533010101d3019e400101000405060708091011121314151630bf310000
ffff8000aaaaaaaaaacaca54aa042143065532010101e601013001010004050607080910111213141516e54de60000
ffff8000aaaaaaaaaacaca54aa042143065732010101d80101300101000405060708091011121314151647a3480000
ffff8000aaaaaaaaaacaca54aa04214b065732010101da010130010100040506070809101112131415166ed46f0000
ffff8000aaaaaaaaaacaca54aa042143065932010101f10101300101000405060708091011121314151681f8820000
ffff8000aaaaaaaaaacaca54aa04df80063533010101d501014001010004050607080910111213141516d114d20000
ffff8000aaaaaaaaaacaca54aa04df80063133010101d9010140010100040506070809101112131415161f62200000
ffff8000aaaaaaaaaacaca54aa04df80062f340101014e0101400101000405060708091011121314151632e9330000
ffff8000aaaaaaaaaacaca54aa040f610645320101013701014001010004050607080910111213141516854a860000
ffff8000aaaaaaaaaacaca54aa046cea061634010101b601034001010004050607080910111213141516acabad0000
ffff8000aaaaaaaaaacaca54aa046cea060b35010101b6010340010100040506070809101112131415165d525e0000
ffff8000aaaaaaaaaacaca54aa046cea059651010101b50103400101000405060708091011121314151613ad140000
ffff8000aaaaaaaaaacaca54aa04df800631340130010101014001010204050607080910111213141516e17ee20000
ffff8000aaaaaaaaaacaca54aa04df80063334012e015c01014001010f04050607080910111213141516575c580000
ffff8000aaaaaaaaaacaca54aa04df80063534013601cf01014001010f040506070809101112131415166aec6b0000
ffff8000aaaaaaaaaacaca54aa04df80063633011601ed0101400101070405060708091011121314151645bd460000
ffff8000aaaaaaaaaacaca54aa04df80063534010101ed010140010100040506070809101112131415161d791e0000
ffff8000aaaaaaaaaacaca54aa04df80063533013801ed01014001010f0405060708091011121314151644e5450000
ffff8000aaaaaaaaaacaca54aa040f610648330123015e01014001010a040506070809101112131415160a260b0000
ffff8000aaaaaaaaaacaca54aa040f610648320101015e01014001010f040506070809101112131415162b292c0000
ffff8000aaaaaaaaaacaca54aa040f61064a320101015e01014001010e04050607080910111213141516b4b3b50000
ffff8000aaaaaaaaaacaca54aa040f610648320101015e010140010119040506070809101112131415169fa7a00000
ffff8000aaaaaaaaaacaca54aa040f61064a320101015e01014001011b04050607080910111213141516d9e5da0000
ffff8000aaaaaaaaaacaca54aa040f610648320101015e01014001010b0405060708091011121314151689838a0000
ffff8000aaaaaaaaaacaca54aa040f610648320101015e01014001010304050607080910111213141516ebddec0000
ffff8000aaaaaaaaaacaca54aa040f61064832010101d9010140010116040506070809101112131415164ccc4d0000
Before the integration of the Emax decoder, I was actually trying to decode my station (independently). Most of my findings matches more or less the W6 ones, except for the data after the rain bits :
4 UV: 0 LUX: 0101 G: 0b CONSTANT: 04050607080910111213141516 CHECKSUM: 89838a (my data)
0 UV: 1 LUX: 0101 CONSTANT: 0405060708091011121314151617 CHECKSUM: 9dad9e (data on W6 notes)
I found out that the G byte correspond to wind gust*1.5. In my example, 0x0b/1.5 = 11/1.5 = 7.3333... and the station displayed 7.3 km/h gust speed. It worked for every test I made.
The constant part is not the same between the 2 models (the W6 has one more byte, to compensate for the lack of G ?) Is it a good idea to differentiate the 2 models by that (in which case, I can open PR for that)
Also, a bit unrelated but for documentation purposes, the battery low flag triggers when voltage <=3.7 V
I'll add some test samples later today
(cc @ProfBoc75 you may be interested ?)