Investigating on values

[rusq]

Hey, great job with getting this working!

For your reference, gattool output for my sensor is

Notification handle = 0x0036 value: eb 08 36 c0 0b 
[A4:C1:38:E9:2A:F3][LE]>

The unknown values for my sensor are c0 0b.
After a while it read e5 0b.

The other one

Notification handle = 0x0036 value: f9 07 3d 78 0c
[A4:C1:38:1F:50:35][LE]>

[JsBergbau]

On my sensor the last value is also 0b
Currently it is e5 0b. last time I checked it was 9f 0b
Current readings are

Temperature: 22.75
Humidity: 53

[julienbrunet]

Hi there,

Thanks a lot for your work.

Here are my values for my 4 sensors :

Notification handle = 0x0036 value: d6 07 33 c9 0c
Notification handle = 0x0036 value: c8 07 30 fd 0b
Notification handle = 0x0036 value: 2a 09 2b dc 0c
Notification handle = 0x0036 value: 58 09 2b b9 0c

[rusq]

if that's a 16-bit word, looks like this parameter is in range 0x0Bxx - 0x0Cxx and doesn't change very often.

[jaggil]

Hey, great job with getting this working!

For your reference, gattool output for my sensor is

Notification handle = 0x0036 value: eb 08 36 c0 0b 
[A4:C1:38:E9:2A:F3][LE]>

The unknown values for my sensor are c0 0b.
After a while it read e5 0b.

The other one

Notification handle = 0x0036 value: f9 07 3d 78 0c
[A4:C1:38:1F:50:35][LE]>

I think it is the value of the battery voltage in mV. This is: 0BC0 hex = 3008 mV= 3.008 V
The sensor updates the battery level every hour or so
The operating range is 2v to 3v. This is 0 to 100% battery
On the other hand, in my case, it seems that the following UUIDs associated with the battery status do not work, and never change the value of 0x64 = 100% or 0x63 = 99%:
UUID 0x189F -> 0x2A19
UUID ebe0ccb0-7a0a-4b0c-8a1a-6ff2997da3a6 -> ebe0ccc4-7a0a-4b0c-8a1a-6ff2997da3a6
Could anyone confirm it?

[JsBergbau]

Thanks for the info. I saw this post with supposed voltage somewhere else a few days ago and wanted to make some tests. Didn't manage yet.

Yeah it seems that the battery value of 99 % never changes.

I had to change the battery in a Aqara because the device went off when placed vertically. Just lying on the table it worked without problems. Battery value read out was still 99 %. The Aqara sensors have a battery indicator which shortly was displayed before this particular device was going off.

I have a voltage meter and a low battery now, so I'll report back in a few days.

[jaggil]

Someone may be interested to know that the LYWSD03MMC sensor has an internal operating RTC. With the advantage of having battery support.

Although the sensor does not present it on the LCD screen, in the UUID ebe0ccb0 -... / ebe0ccb7 -... maintains the date and time in UnixTime format (seconds since Jan 01 1970. (UTC) - https: // www.unixtimestamp.com/index.php).

This UUID allows Read and Write.
The structure of the bytes is as follows:
Raw reading -> B3-B2-B1-B0 (endian littel format)
Decoded reading -> B0 B1 B2 B3 (total seconds since 01-01-1970)

To initialize the UUID, you must write the desired Date / Time with the bytes in the raw format (endian littel format).

Of course, you have to take into account the time zone

[JsBergbau]

I can confirm now last to bytes are the battery voltage. Note: When measuring the battery outside the device battery level is about 0,15 V higher than displayed on the last 2 bytes. To measure "the real" voltage when Aqara sensor is sending data, I put a wire under the contact for the minus pole. On my measurement the voltage bounced about 0,05 V. Thats very strange since Bluetooth low energy consumes very little power. I think the batteries included in the Aqara are from low quality. Out of 8 sensors I now have two with empty batteries. But not the ones I'm using the longest time. I suspect bad battery quality for the second delivery.
I'll rewrite the script to read out the battery voltage. My first Aqara which is now running since first or second week of January now has 2554 mV.
A brand new Aqara which now was just lying around for about 2 weeks without any connection had 2885 mV measured outside. Another 3014 mV and another 2089 mV.

[jaggil]

Hi JsBergbau, when you say Aqara (product name WSDCGQ11LM) is that the same as LYWSD03MMC?
Sorry I do not understand, I thought that Aqara are Zigbee protocol equipment, right?
Is there a BLE version of Aqara sensors?

[jaggil]

JsBergbau: " My first Aqara which is now running since first or second week of January now has 2554 mV. "
Those sensors seem to spend a lot of battery. In six / seven weeks the sensor has spent 50% of battery, or as you say, the batteries are from low quality.
In my tests, I have verified that when the voltage reaches 2.1 V, the empty battery icon is activated, and it is imminent that LYWSD03MMC sensor turns off.

[rusq]

I was running with a constant connection for about a month (I got 7 of those sensors, out of which 4 was polled for the home assistant), in two of them battery died - those which were not polled have 3.06V on the battery and in two discharged ones the voltmeter shows 2.6V, so I guess having a constant connection isn't very good idea. It's notable as both of them discharged with the difference of several ours.

[rusq]

Oh, and for the record, the battery level that was retrieved via polling was always 99%, even minutes before they shut down, so the battery percentage is not reliable. @jaggil, great finding! @JsBergbau awesome idea on having these as a battery level.

For the reference - 2.75V can be considered as 0%, as that's the voltage on a completely dead sensor. When plugged in into back the sensor, it doesn't turn on. It's the same battery that was showing ~2.6 before, I guess the voltage drops over the time and restores up to a certain point, I'm no batterologist.

[jaggil]

In my battery tests I have used an adjustable power supply, and the summary is as follows:
1.- The operating range is between 2.1v to 3v.
2.- When 2.1 v is reached, the empty battery icon is activated on the LCD screen.
Also, the "UUID ebe0ccb0-7a0a-4b0c-8a1a-6ff2997da3a6 -> ebe0ccc4-7a0a-4b0c-8a1a-6ff2997da3a6" changes value from 0x64 to 0x0A (I guess it is 100% to 10%). This change may take an hour or so.
I guess it's a binary indicator of battery status.
Of course, in this voltage the brightness of the screen is minimal, and it is difficult to see the data.
3.- When it reaches 2.09v, the sensor turns off.
My conclusion is that the 0 to 100% battery range corresponds to 2.1v to 3v
@rusq Thank you/Gracias

OK friends,
Now that we know the battery's operating range, I think it is necessary to reopen issue # 10 to determine the best way to communicate with the sensor, in order for the battery to last the maximum time.
I don't know if it is better to have a permanent connection and receive the data every 6 seconds, or make connections every 5 minutes (or the time that each project needs) and once the data is received, make a disconnection.

[JsBergbau]

Hi JsBergbau, when you say Aqara (product name WSDCGQ11LM) is that the same as LYWSD03MMC?
Sorry I do not understand, I thought that Aqara are Zigbee protocol equipment, right?
Is there a BLE version of Aqara sensors?

Where did you read that WSDCGQ11LM and LYWSD03MMC are the same? I even don't know WSDCGQ11LM sensor....
The LYWSD03MMC are Bluetooth Low Energy sensors.

[jaggil]

Hi JsBergbau, when you say Aqara (product name WSDCGQ11LM) is that the same as LYWSD03MMC?
Sorry I do not understand, I thought that Aqara are Zigbee protocol equipment, right?
Is there a BLE version of Aqara sensors?

Where did you read that WSDCGQ11LM and LYWSD03MMC are the same? I even don't know WSDCGQ11LM sensor....
The LYWSD03MMC are Bluetooth Low Energy sensors.

As I understand it, we have two different products:
Aqara (product name WSDCGQ11LM with Zigbee protocol)
Xiaomi MiTemperature2 (LYWSD03MMC with BLE)

But you make many references to the Aqara sensor and that confuses me if you mean one or the other.

[JsBergbau]

Oh, and for the record, the battery level that was retrieved via polling was always 99%, even minutes before they shut down, so the battery percentage is not reliable.

I can confim that.

For the reference - 2.75V can be considered as 0%, as that's the voltage on a completely dead sensor. When plugged in into back the sensor, it doesn't turn on. It's the same battery that was showing ~2.6 before,

Currently my sensor with the lowest batterylevel is running at 2.29 V. The voltage even recovers a bit, it now was 2.32 V.

I guess the voltage drops over the time and restores up to a certain point, I'm no batterologist.
If you pull the battery out and hold it in your hands, it gets warmer and thus recovers a few mV, so that the sensor could turn on again.

I've implemented now reading out the voltage and will impemtent the -b option to give an estimated percent value. For compatbility reasons you can still specifiy a number after b but it will be ignored.