Xiaomi-Mijia-Bluetooth-Temperature-and-Humidity-Sensor

KO | EN

gitlite — search

#javascript #typescript #llm #go #golang #android #deep-learning #docker #awesome #kubernetes #vue #pytorch #openai #open-source

Xiaomi-Mijia-Bluetooth-Temperature-and-Humidity-Sensor

(★ 51)

Xiaomi-Mijia-Bluetooth-Temperature-and-Humidity-Sensor

File Explorer

Download Latest Version (.zip)

bluetooth.c
bluetooth.h
hci.c
hci.h
hci_lib.h
Makefile
oui.c
oui.h
README.md
scanMijia.c
SensorProtocol.html

// repository documentation

Was this content helpful?

★ 0 (0 ratings)

# Xiaomi-Mijia-Bluetooth-Temperature-and-Humidity-Sensor

Developed starting from Bluez hcitool, this tool is able to
read the data sent as BLE advertisements by the Xiaomi
Mijia Bluetooth temperature and humidity sensor.

You should have already installed the Bluetooh Bluez stack.

Issue 'make' to build the tool. 
Then issue scanMijia -h to show detailed help.

Like the original hcitool command, also this tool should be
run from root.

Below is a brief description of the sensor protocol.

<html>

</head>

<h1>Sensor protocol specification:</h1>

&nbsp;
As soon as the battery is inserted, the sensor starts sending
adverisement data every two seconds and the advertisement data contiains all
the useful information (Temperature, Humidity and Battery Level). 
You can test it with the two Bluez commands hcitool and hcidump (or any other
tool able to read advertisemnt data sent by BLE devices). 
In order to show the raw data sent by the sensor, you should first start in
background a BT le scan in 'passive mode' and then print the raw data. 
'Passive mode' means that you are not sending any request to the sensor but you
are just reciving the advertisements sent by the BLE devices. 
If you scan in normal mode (without --passive option), you will send a scan
request and the the device will send some other additional data (Sensor Name,
available UUIDs) but it is not necessary and you will only waste the sensor
battery.

sudo hcitool lescan --passive &amp;

hcidump --raw

Looking at the hcidump output you can identify four type of
messages.

<h2>Messages examples:</h1>

<h3>Temperature &amp; Humidity:</h3>

<table class=MsoTableGrid border=1 cellspacing=0 cellpadding=0 width=669
 style='width:501.55pt;border-collapse:collapse;border:none'>
 <tr>
 <td width=140 valign=top style='width:104.65pt;border:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 Header
 </td>
 <td width=529 valign=top style='width:14.0cm;border:solid windowtext 1.0pt;
 border-left:none;padding:0cm 5.4pt 0cm 5.4pt'>
 04
 3E 25 02 01 00 00 XX XX XX XX XX XX 19
 </td>
 </tr>
 <tr>
 <td width=140 valign=top style='width:104.65pt;border:solid windowtext 1.0pt;
 border-top:none;padding:0cm 5.4pt 0cm 5.4pt'>
 Flags
 AD
 </td>
 <td width=529 valign=top style='width:14.0cm;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 02
 01 06
 </td>
 </tr>
 <tr>
 <td width=140 valign=top style='width:104.65pt;border:solid windowtext 1.0pt;
 border-top:none;padding:0cm 5.4pt 0cm 5.4pt'>
 Service
 Data AD
 </td>
 <td width=529 valign=top style='width:14.0cm;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 15
 16 95 FE 50 20 AA 01 17 XX XX XX XX XX XX 0D
 10 04 B9 00 5C 02
 </td>
 </tr>
 <tr>
 <td width=140 valign=top style='width:104.65pt;border:solid windowtext 1.0pt;
 border-top:none;padding:0cm 5.4pt 0cm 5.4pt'>
 RSSI
 </td>
 <td width=529 valign=top style='width:14.0cm;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 A4
 </td>
 </tr>
</table>

&nbsp;

<h3>Battery Level:</h3>

<table class=MsoTableGrid border=1 cellspacing=0 cellpadding=0 width=669
 style='width:501.55pt;border-collapse:collapse;border:none'>
 <tr>
 <td width=140 valign=top style='width:104.65pt;border:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 Header
 </td>
 <td width=529 valign=top style='width:14.0cm;border:solid windowtext 1.0pt;
 border-left:none;padding:0cm 5.4pt 0cm 5.4pt'>
 04
 3E 22 02 01 00 00 XX XX XX XX XX XX 16
 </td>
 </tr>
 <tr>
 <td width=140 valign=top style='width:104.65pt;border:solid windowtext 1.0pt;
 border-top:none;padding:0cm 5.4pt 0cm 5.4pt'>
 Flags
 AD
 </td>
 <td width=529 valign=top style='width:14.0cm;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 02
 01 06
 </td>
 </tr>
 <tr>
 <td width=140 valign=top style='width:104.65pt;border:solid windowtext 1.0pt;
 border-top:none;padding:0cm 5.4pt 0cm 5.4pt'>
 Service
 Data AD
 </td>
 <td width=529 valign=top style='width:14.0cm;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 12
 16 95 FE 50 20 AA 01 12 XX XX XX XX XX XX 0A
 10 01 64
 </td>
 </tr>
 <tr>
 <td width=140 valign=top style='width:104.65pt;border:solid windowtext 1.0pt;
 border-top:none;padding:0cm 5.4pt 0cm 5.4pt'>
 RSSI
 </td>
 <td width=529 valign=top style='width:14.0cm;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 A6
 </td>
 </tr>
</table>

&nbsp;

<h3>Humidity:</h3>

<table class=MsoTableGrid border=1 cellspacing=0 cellpadding=0 width=669
 style='width:501.55pt;border-collapse:collapse;border:none'>
 <tr>
 <td width=140 valign=top style='width:104.65pt;border:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 Header
 </td>
 <td width=529 valign=top style='width:14.0cm;border:solid windowtext 1.0pt;
 border-left:none;padding:0cm 5.4pt 0cm 5.4pt'>
 04
 3E 23 02 01 00 00 XX XX XX XX XX XX 17
 </td>
 </tr>
 <tr>
 <td width=140 valign=top style='width:104.65pt;border:solid windowtext 1.0pt;
 border-top:none;padding:0cm 5.4pt 0cm 5.4pt'>
 Flags
 AD
 </td>
 <td width=529 valign=top style='width:14.0cm;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 02
 01 06
 </td>
 </tr>
 <tr>
 <td width=140 valign=top style='width:104.65pt;border:solid windowtext 1.0pt;
 border-top:none;padding:0cm 5.4pt 0cm 5.4pt'>
 Service
 Data AD
 </td>
 <td width=529 valign=top style='width:14.0cm;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 13
 16 95 FE 50 20 AA 01 14 XX XX XX XX XX XX 06
 10 02 5C 02
 </td>
 </tr>
 <tr>
 <td width=140 valign=top style='width:104.65pt;border:solid windowtext 1.0pt;
 border-top:none;padding:0cm 5.4pt 0cm 5.4pt'>
 RSSI
 </td>
 <td width=529 valign=top style='width:14.0cm;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 A6
 </td>
 </tr>
</table>

&nbsp;

<h3>Temperature:</h3>

<table class=MsoTableGrid border=1 cellspacing=0 cellpadding=0 width=669
 style='width:501.55pt;border-collapse:collapse;border:none'>
 <tr>
 <td width=140 valign=top style='width:104.65pt;border:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 Header
 </td>
 <td width=529 valign=top style='width:14.0cm;border:solid windowtext 1.0pt;
 border-left:none;padding:0cm 5.4pt 0cm 5.4pt'>
 04
 3E 23 02 01 00 00 XX XX XX XX XX XX 17
 </td>
 </tr>
 <tr>
 <td width=140 valign=top style='width:104.65pt;border:solid windowtext 1.0pt;
 border-top:none;padding:0cm 5.4pt 0cm 5.4pt'>
 Flags
 AD
 </td>
 <td width=529 valign=top style='width:14.0cm;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 02
 01 06
 </td>
 </tr>
 <tr>
 <td width=140 valign=top style='width:104.65pt;border:solid windowtext 1.0pt;
 border-top:none;padding:0cm 5.4pt 0cm 5.4pt'>
 Service
 Data AD
 </td>
 <td width=529 valign=top style='width:14.0cm;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 13
 16 95 FE 50 20 AA 01 19 XX XX XX XX XX XX 04
 10 02 B9 00
 </td>
 </tr>
 <tr>
 <td width=140 valign=top style='width:104.65pt;border:solid windowtext 1.0pt;
 border-top:none;padding:0cm 5.4pt 0cm 5.4pt'>
 RSSI
 </td>
 <td width=529 valign=top style='width:14.0cm;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 A7
 </td>
 </tr>
</table>

&nbsp;

The &quot;Service Data AD&quot; is the part of the message that
carries the useful information.

XX .. XX are the BT addres of the device, red values is the data
type and green values are the data values.

But first we will give a look to the whole message.

<h2>Message Description</h1>

As example we will use the Temperature
&amp; Humidity message.

&nbsp;

04 3E 25 02
01 00 00 XX XX XX XX XX XX 19 02 01 06 15 16 95 FE 50 20 AA 01 17 XX XX XX
XX XX XX 0D 10 04 B9 00 5C 02 A6

&nbsp;

<table class=MsoTableGrid border=1 cellspacing=0 cellpadding=0 width=659
 style='width:494.45pt;border-collapse:collapse;border:none'>
 <tr>
 <td width=46 valign=top style='width:34.85pt;border:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 &nbsp;
 </td>
 <td width=62 valign=top style='width:46.85pt;border:solid windowtext 1.0pt;
 border-left:none;padding:0cm 5.4pt 0cm 5.4pt'>
 Pos.
 </td>
 <td width=62 valign=top style='width:46.85pt;border:solid windowtext 1.0pt;
 border-left:none;padding:0cm 5.4pt 0cm 5.4pt'>
 Value (hex)
 </td>
 <td width=488 valign=top style='width:365.9pt;border:solid windowtext 1.0pt;
 border-left:none;padding:0cm 5.4pt 0cm 5.4pt'>
 Description
 </td>
 </tr>
 <tr>
 <td width=46 rowspan=9 valign=top style='width:34.85pt;border:solid windowtext 1.0pt;
 border-top:none;padding:0cm 5.4pt 0cm 5.4pt'>
 &nbsp;
 Header
 </td>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 0
 </td>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 04
 </td>
 <td width=488 valign=top style='width:365.9pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 HCI
 Packet Type HCI Event
 </td>
 </tr>
 <tr>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 1
 </td>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 3E
 </td>
 <td width=488 valign=top style='width:365.9pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 LE
 Meta event
 </td>
 </tr>
 <tr>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 2
 </td>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 25
 </td>
 <td width=488 valign=top style='width:365.9pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 Nr
 of following bytes (37 bytes)
 </td>
 </tr>
 <tr>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 3
 </td>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 02
 </td>
 <td width=488 valign=top style='width:365.9pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 LE
 Advertising report sub-event
 </td>
 </tr>
 <tr>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 4
 </td>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 01
 </td>
 <td width=488 valign=top style='width:365.9pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 Number
 of reports
 </td>
 </tr>
 <tr>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 5
 </td>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 00
 </td>
 <td width=488 valign=top style='width:365.9pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 Event
 type (connectable and scannable undirected advertising)
 </td>
 </tr>
 <tr style='height:7.5pt'>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 6
 </td>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 00
 </td>
 <td width=488 valign=top style='width:365.9pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 Public
 address type
 </td>
 </tr>
 <tr style='height:7.5pt'>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 7..12
 </td>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 XX..XX
 </td>
 <td width=488 valign=top style='width:365.9pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 BT Address (6 bytes)
 </td>
 </tr>
 <tr style='height:7.5pt'>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 13
 </td>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 19
 </td>
 <td width=488 valign=top style='width:365.9pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 length
 of data field (25 bytes)
 </td>
 </tr>
 <tr style='height:7.5pt'>
 <td width=46 rowspan=6 valign=top style='width:34.85pt;border:solid windowtext 1.0pt;
 border-top:none;padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 &nbsp;
 Data
 </td>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 14
 </td>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 02
 </td>
 <td width=488 valign=top style='width:365.9pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 length
 of first advertising data (AD)structure
 </td>
 </tr>
 <tr style='height:7.5pt'>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 15
 </td>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 01
 </td>
 <td width=488 valign=top style='width:365.9pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'><pre>type of first AD structure (0x01 = Flags)</pre></td>
 </tr>
 <tr style='height:7.5pt'>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 16
 </td>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 06
 </td>
 <td width=488 valign=top style='width:365.9pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 first
 AD data (0x06=LE General Discoverable Mode &amp;&amp; BR/EDR Not Supported)
 </td>
 </tr>
 <tr style='height:7.5pt'>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 17
 </td>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 15
 </td>
 <td width=488 valign=top style='width:365.9pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 length
 of second advertising data (AD) structure 
 </td>
 </tr>
 <tr style='height:7.5pt'>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 18
 </td>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 16
 </td>
 <td width=488 valign=top style='width:365.9pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 type
 of second AD structure (0x16=Service Data)
 </td>
 </tr>
 <tr style='height:7.5pt'>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 19..38
 </td>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 95..02
 </td>
 <td width=488 valign=top style='width:365.9pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 Second AD data (see next table for details)
 </td>
 </tr>
 <tr style='height:7.5pt'>
 <td width=46 valign=top style='width:34.85pt;border:solid windowtext 1.0pt;
 border-top:none;padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 RSSI
 </td>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 39
 </td>
 <td width=62 valign=top style='width:46.85pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 A6
 </td>
 <td width=488 valign=top style='width:365.9pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt;height:7.5pt'>
 RSSI
 value (signed byte, 0xA6=-90)
 </td>
 </tr>
</table>

&nbsp;

<h2>Service Data AD</h1>

The most important information is contained
into the second AD structure (type 0x16).

The Bluetooth specification defines the AD
Type 0x16 as �Service Data�. This AD �must contain at least two bytes
representing the 16 bit UUID of this Service Data. The data following the UUID�
is custom data and the meaning is not defined in the Bluetooth specification.

The table below shows the meaning of ��Service Data� AD for our sensor.
As example we will use the Service Data AD of the same Temperature &amp;
Humidity message as above.

95
FE 50 20 AA 01 17 XX XX XX XX XX XX 0D 10 04 B9 00 5C 02

&nbsp;

<table class=MsoTableGrid border=1 cellspacing=0 cellpadding=0 width=603
 style='width:451.95pt;border-collapse:collapse;border:none'>
 <tr>
 <td width=62 valign=top style='width:46.85pt;border:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 &nbsp;
 </td>
 <td width=58 valign=top style='width:43.6pt;border:solid windowtext 1.0pt;
 border-left:none;padding:0cm 5.4pt 0cm 5.4pt'>
 Pos.
 </td>
 <td width=104 valign=top style='width:78.0pt;border:solid windowtext 1.0pt;
 border-left:none;padding:0cm 5.4pt 0cm 5.4pt'>
 Value (Hex)
 </td>
 <td width=378 valign=top style='width:10.0cm;border:solid windowtext 1.0pt;
 border-left:none;padding:0cm 5.4pt 0cm 5.4pt'>
 Description
 </td>
 </tr>
 <tr>
 <td width=62 valign=top style='width:46.85pt;border:solid windowtext 1.0pt;
 border-top:none;padding:0cm 5.4pt 0cm 5.4pt'>
 16
 bit UUID
 </td>
 <td width=58 valign=top style='width:43.6pt;border-top:none;border-left:none;
 border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 0..1
 </td>
 <td width=104 valign=top style='width:78.0pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 95
 FE
 </td>
 <td width=378 valign=top style='width:10.0cm;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 UUID
 16 bit (0xFE95)
 </td>
 </tr>
 <tr>
 <td width=62 rowspan=7 valign=top style='width:46.85pt;border:solid windowtext 1.0pt;
 border-top:none;padding:0cm 5.4pt 0cm 5.4pt'>
 &nbsp;
 Custom Data
 </td>
 <td width=58 valign=top style='width:43.6pt;border-top:none;border-left:none;
 border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 2..5
 </td>
 <td width=104 valign=top style='width:78.0pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 50
 20 AA 01
 </td>
 <td width=378 valign=top style='width:10.0cm;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 TBD
 (always 50 20 AA 01)
 </td>
 </tr>
 <tr>
 <td width=58 valign=top style='width:43.6pt;border-top:none;border-left:none;
 border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 6
 </td>
 <td width=104 valign=top style='width:78.0pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 17
 </td>
 <td width=378 valign=top style='width:10.0cm;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 Message
 counter (increments by 1 every message and then restart from 0 when reaches
 FF)
 </td>
 </tr>
 <tr>
 <td width=58 valign=top style='width:43.6pt;border-top:none;border-left:none;
 border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 7..12
 </td>
 <td width=104 valign=top style='width:78.0pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 XX
 XX XX XX XX XX
 </td>
 <td width=378 valign=top style='width:10.0cm;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 Device
 BT address (6 bytes)
 </td>
 </tr>
 <tr>
 <td width=58 valign=top style='width:43.6pt;border-top:none;border-left:none;
 border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 13
 </td>
 <td width=104 valign=top style='width:78.0pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 0D
 
 </td>
 <td width=378 valign=top style='width:10.0cm;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 Data
 type: 
 0D -&gt; Temperature &amp; Humidity (4 bytes TL,TH,HL,HH) 
 0A -&gt; battery % (1 byte) 
 06 -&gt; only Humidity (2 bytes HL,HH) 
 04 -&gt; only Temperature (2 bytes TL, TH)
 </td>
 </tr>
 <tr>
 <td width=58 valign=top style='width:43.6pt;border-top:none;border-left:none;
 border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 14
 </td>
 <td width=104 valign=top style='width:78.0pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 10
 </td>
 <td width=378 valign=top style='width:10.0cm;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 TBD
 (always 0x10)
 </td>
 </tr>
 <tr>
 <td width=58 valign=top style='width:43.6pt;border-top:none;border-left:none;
 border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 15
 </td>
 <td width=104 valign=top style='width:78.0pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 04
 </td>
 <td width=378 valign=top style='width:10.0cm;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 Nr
 of following bytes (depends on Data Type)
 </td>
 </tr>
 <tr>
 <td width=58 valign=top style='width:43.6pt;border-top:none;border-left:none;
 border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 16..N
 </td>
 <td width=104 valign=top style='width:78.0pt;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 B9
 00 5C 02
 </td>
 <td width=378 valign=top style='width:10.0cm;border-top:none;border-left:
 none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
 padding:0cm 5.4pt 0cm 5.4pt'>
 Data
 values: 
 0x00B9 = 185 -&gt; 18.5 C 
 0x025C = 604 -&gt; 60.4 %
 </td>
 </tr>
</table>

&nbsp;

</div>

</body>

</html>

Xiaomi-Mijia-Bluetooth-Temperature-and-Humidity-Sensor

File Explorer

Today's picks

Was this content helpful?

Recent Feedback

Xiaomi-Mijia-Bluetooth-Temperature-and-Humidity-Sensor

File Explorer

Today's picks

Was this content helpful?

Recent Feedback

Download README