Author Topic: New Acurite Lightning Detector  (Read 8061 times)

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Offline n7qnm

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Re: New Acurite Lightning Detector
« Reply #50 on: February 17, 2017, 10:24:13 PM »
3716 - a sticker on the lid of the battery compartment

Offline rct

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Re: New Acurite Lightning Detector
« Reply #51 on: February 27, 2017, 06:52:47 PM »
The one which I used to implement the current experimental code in rtl_433, has a label QC 3016.  I suspected that the temperature sensor at a minimum might be bad. I got it during the (early?) summer, don't know if it's already out of warranty.   There is a bunch of things that seem to be erratic about it.  I had trouble nailing down which bit was battery low (or battery good).  I thought it's the LSB in the status byte.  It usually is on.   Turned off when the voltage was low, but then it stayed off for a while.  Didn't seem to behave sensibly. I eventually gave up on it.

Note: while a number of the other Acurite devices spit out JSON in rtl_433, the 6045M code still just outputs plain text.  including a dump of all bytes received since I never finishing figuring out the encoding.

Offline rct

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Re: New Acurite Lightning Detector
« Reply #52 on: March 19, 2017, 05:12:28 PM »
A little bit of a status update for receiving the 06045 lightning sensor with rtl_433 (and an RTL-SDR).  Clay, N7QNM, motivated me enough to get my 06045 back out of the box and take another swing at figuring out the decoding.

I believe I've finally got the temperature figured out. There appears to be 12 bits for temperature.  The native units in the message appear to be in tenths of a degree Fahrenheit.   I've tested from around -2 F (freezer) to 90 F.

the rtl_433 output has changed slightly. Currently the output looks like this:

Code: [Select]
2016-10-24 18:48:12 Acurite lightning 0xE86F Ch B Msg Type 0x00: 74.1 F 43 % RH Strikes 5 Distance 0 L_status 0x02 - 80* e8 6f 2b 11 41 05 c0 19*
The changes in parsing are:
  • Temperature in Fahrenheit instead of Celsius.
  • The distance field is more reasonable but doesn't match the display.  I think 5 bits are used for distance.  0x1f (decimal 31) seems to be an invalid/undefined value.  This is the value when the sensor powers up.  I don't have a compatible display,  I could use some data from anyone who does with correlations between what rtl_433 is outputting and what the display shows.
  • New field "L_status", lightning/distance status bits that I haven't quite figured out yet.  The lower of the 2 bits (1) toggles on for interference / RF noise detected.
  • "Message Type" is just 2 status bits now that I've figured out the rest of those bits were temperature MSB.  The higher bit (2) seems to indicate the sensor is in active mode, transmitting every 8 sections instead of the regular 24.  I have not been able to get the lower bit (1) to be on.  My guess is this should be battery low if on (see below).

Has anyone that has the sensor with a compatible Acurite display ever seen it indicate low battery?    I've been trying to see which bit might indicate low battery, but I haven't seen anything so far.  I have it on a variable supply running at about 2.2 Vdc, just above where it will die from insufficient power. 

I still have to spend sometime digesting the data sheet that was posted in the tear down thread by George.

I put some documentation for the message format in the rtl_433 source code. (src/devices/acurite.c).



Offline rct

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Re: New Acurite Lightning Detector
« Reply #53 on: April 07, 2017, 12:32:19 PM »
More on trying to decode the raw bytes from the lightning sensor with rtl_433:

Heads up - my assumption about the 2nd and 3rd bytes bytes being used for the sensor ID in the raw message might be wrong.  This might affect weewx-sdr users.

Generally, I've seen the 3rd byte as a fixed value of 0x6f.  I got a new sensor about a month ago.  The 3rd byte was a fixed 0xaf, which seemed to confirm that it is part of the ID.   However, I just noticed after 3-4 weeks that sensor started sending 0x6f instead of 0xaf.   Since it changed it's only been sending 0x6f.    I don't have any guesses/clues as to why it changed or what that byte/those bits might represent.  I don't think it is low battery, because I didn't see any change with a variable power supply.   

(You'll notice that two bits changed, 0xa = 0b1010 -> 0x6 = 0b0110.  This actually makes sense if this is one of the data bytes and not an ID byte, since data bytes are 7 bits and used the 8th for parity checking.  The ID bytes and checksum use all 8 bits, so no room for parity.)

I'm interested if you've seen an ID / 3rd byte value that isn't 0x6f.   I'm especially interested if you've seen it change and have any clues why.

Code: [Select]
2017-04-07 12:29:04 Acurite lightning 0xD56F Ch B Msg Type 0x00: 55.2 F 57 % RH Strikes 17 Distance 22 L_status 0x00 - 80* d5* 6f  39  90  84  11  96  b8

Offline mwall

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Re: New Acurite Lightning Detector
« Reply #54 on: April 07, 2017, 12:51:06 PM »
bob,

this is the output from one of my lightning sensors:
Code: [Select]
Acurite lightning 0x526F Ch A Msg Type 0x50: 112 C 48 % RH Strikes 1 Distance 81 - dd  52* 6f  30  50  f0  81  d1  60the 3rd byte has been 0x6f for as long as i've had the sensor (dec 2016).

i have an older sensor (aug 2016) at a different, remote location, but i have not been recording its output - it beeps all the time, even when there is no electrical activity.  acurite said it was defective.

m

Offline craigthom

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Re: New Acurite Lightning Detector
« Reply #55 on: April 10, 2017, 08:47:36 AM »
If it helps, this is the output from my lightning sensor.  I bought it week before last.

Code: [Select]
Acurite lightning 0x6FAF Ch A Msg Type 0x02: 65.1 F 42 % RH Strikes 32 Distance 12 L_status 0x02 - c0  6f  af  aa  50  e7  a0  cc  2b

Offline rct

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Re: New Acurite Lightning Detector
« Reply #56 on: April 10, 2017, 09:05:20 AM »
the 3rd byte has been 0x6f for as long as i've had the sensor (dec 2016).

i have an older sensor (aug 2016) at a different, remote location, but i have not been recording its output - it beeps all the time, even when there is no electrical activity.  acurite said it was defective.

Matthew - Thanks for that data point. 

If it helps, this is the output from my lightning sensor.  I bought it week before last.

Code: [Select]
Acurite lightning 0x6FAF Ch A Msg Type 0x02: 65.1 F 42 % RH Strikes 32 Distance 12 L_status 0x02 - c0  6f  af  aa  50  e7  a0  cc  2b

Craig - Thanks -  that's interesting, another new, out-of-the-box sensor with the 0xaf value.  Let me know if that changes to 0x6f or anything else.   Wild guess - Maybe it's some sort of learning mode indicator.

--Rob

Offline craigthom

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Re: New Acurite Lightning Detector
« Reply #57 on: April 22, 2017, 12:54:07 AM »
Craig - Thanks -  that's interesting, another new, out-of-the-box sensor with the 0xaf value.  Let me know if that changes to 0x6f or anything else.   Wild guess - Maybe it's some sort of learning mode indicator.

--Rob

No change yet.  All the bytes after the af have changed, but I suppose the that's temp/humidity/strikes/distance data.

Offline rct

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Re: New Acurite Lightning Detector
« Reply #58 on: April 23, 2017, 10:48:55 AM »
Thanks for the info Craig.  Yes, all the bytes after the 0x6f or 0xaf are data bytes.  src/devices/acurite.c has some docs.   I think it was 3-4 weeks before my sensor flipped from 0xaf to 0xaf.

Offline craigthom

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Re: New Acurite Lightning Detector
« Reply #59 on: January 03, 2018, 04:38:30 PM »
OK, I was getting low humidity readings from my lightning sensor, and it's cold, so I replaced the NiMH batteries with alkalines, and they weewx stopped recording it.

I checked, and, sure enough, that AF changed to a 6F, so what I'm now showing as sensor ID is 6F6F instead of 6FAF.  So maybe it took a power cycle to change.

 

anything