NoiseMeter - Revision history

Bertrik Sikken: /* Uni-T UT353 BT noise meter */

2025-09-21T13:22:32Z

Uni-T UT353 BT noise meter

← Older revision		Revision as of 13:22, 21 September 2025
Line 94:		Line 94:
	=== Uni-T UT353 BT noise meter ===		=== Uni-T UT353 BT noise meter ===
	This thing has bluetooth.		This thing has bluetooth.
			There is an internal serial port that can be monitored.

			It also has a bluetooth interface. This bluetooth implements a "standard" unofficial serial-over-BLE interface.
			This should be compatible with the python 'ble-serial' package

	==== serial interface ====		==== serial interface ====
	~~Interpreting serial port data on Linux is not straightforward, since Linux treats a serial port as a terminal so by default it does terminal-specific stuff to the data.~~
	~~The data below may have been corrupted by the Linux tty subsystem trying to escape/unescape certain byte sequences.~~

	There is an internal serial interface (9600 bps).		There is an internal serial interface (9600 bps).
	Use the following to configure the serial port on linux		Use the following to configure the serial port on linux
Line 160:		Line 161:
	AA BB 04 FF 00 02 68		AA BB 04 FF 00 02 68
	</pre>		</pre>
			Analyzed:
			* AA BB are fixed header bytes
			* 04 is the length of the following data
			* FF is the 'type'
			* 00 is the payload
			* 02 68 is a checksum, the sum of the first 4 bytes, stored as big endian

	It now becomes more obvious that the AA BB sequence is a header, followed by a length byte		It now becomes more obvious that the AA BB sequence is a header, followed by a length byte

Bertrik Sikken: /* Introduction */

2024-04-29T09:19:29Z

Introduction

← Older revision		Revision as of 09:19, 29 April 2024
Line 27:		Line 27:
	Other interesting stuff:		Other interesting stuff:
	* My brother looked inside three inexpensive sound meters: https://twitter.com/jrsikken/status/1779225176464392685		* My brother looked inside three inexpensive sound meters: https://twitter.com/jrsikken/status/1779225176464392685
			* Heatmap of my noise sensor over the past 24h: https://vmi612554.contaboserver.net/b3-grafana/d/zCKDN4oVk/heatmap-spectrum?orgId=2&refresh=1m&var-vsensor=soundkit-023&var-vtype=LZ&var-vfreq=All&from=now-12h&to=now

	== Hardware ==		== Hardware ==

Bertrik Sikken: /* serial interface */

2024-04-25T20:52:48Z

serial interface

← Older revision		Revision as of 20:52, 25 April 2024
Line 154:		Line 154:
	AA BB 10 01 3B 20 20 34 35 2E 32 64 42 41 3D 33 04 04 15 ....; 45.2dBA=3...		AA BB 10 01 3B 20 20 34 35 2E 32 64 42 41 3D 33 04 04 15 ....; 45.2dBA=3...
	</pre>		</pre>
	It now becomes more obvious that the AA BB sequence is a header, ~~with one~~ byte ~~following as the length~~
			When toggling the hold button on the Android app, we see
			<pre>
			AA BB 04 FF 00 02 68
			</pre>

			It now becomes more obvious that the AA BB sequence is a header, followed by a length byte

	==== BLE interface ====		==== BLE interface ====

Bertrik Sikken: /* serial interface */

2024-04-25T20:49:39Z

serial interface

← Older revision		Revision as of 20:49, 25 April 2024
Line 133:		Line 133:
	</pre>		</pre>

	~~===== footer =====~~		Footer
	<pre>		<pre>
	3d 34 XX 04 YY		3d 34 XX 04 YY
Line 143:		Line 143:
	</pre>		</pre>

			Each frame is 23 (x017) bytes long

			With the Android app connected, it sends smaller frames, like
	~~Each frame~~ is ~~23 (x017) bytes long~~		<pre>
			AA BB 10 01 3B 20 20 34 35 2E 34 64 42 41 3D 33 04 04 17 ....; 45.4dBA=3...
			AA BB 10 01 3B 20 20 34 35 2E 32 64 42 41 3D 33 04 04 15 ....; 45.2dBA=3...
			AA BB 10 01 3B 20 20 34 35 2E 32 64 42 41 3D 33 04 04 15 ....; 45.2dBA=3...
			AA BB 10 01 3B 20 20 34 35 2E 32 64 42 41 3D 33 04 04 15 ....; 45.2dBA=3...
			AA BB 10 01 3B 20 20 34 35 2E 32 64 42 41 3D 33 04 04 15 ....; 45.2dBA=3...
			AA BB 10 01 3B 20 20 34 35 2E 32 64 42 41 3D 33 04 04 15 ....; 45.2dBA=3...
			</pre>
			It now becomes more obvious that the AA BB sequence is a header, with one byte following as the length

	==== BLE interface ====		==== BLE interface ====

Bertrik Sikken: /* serial interface */

2024-04-25T20:40:35Z

serial interface

← Older revision		Revision as of 20:40, 25 April 2024
Line 103:		Line 103:
	Then dump using		Then dump using
	cat /dev/ttyUSB0 \|hexdump -C		cat /dev/ttyUSB0 \|hexdump -C
			or
			jpnevulator --tty=/dev/ttyUSB0 --read --width 23 --ascii

	When in bluetooth mode, there is data going over this interface:		When in bluetooth mode, there is data going over this interface:

Bertrik Sikken: /* footer */

2024-04-25T20:40:05Z

footer

← Older revision		Revision as of 20:40, 25 April 2024
Line 136:		Line 136:
	^--- ????		^--- ????
	^--- is 34 in slow mode, 33 in fast mode		^--- is 34 in slow mode, 33 in fast mode
	^--- ~~is 1 in~~ hold ~~mode~~, ~~0 in normal mode~~		^--- buttons pressed: 01 = hold, 04 = min, 08 = max
	^--- always 04		^--- always 04?
	^--- varies between 10, 11, 12, 13, 14, 15, 16, 17, 19, 1B		^--- varies between 10, 11, 12, 13, 14, 15, 16, 17, 19, 1B
	</pre>		</pre>

Bertrik Sikken: /* footer */

2024-04-25T20:23:50Z

footer

← Older revision		Revision as of 20:23, 25 April 2024
Line 139:		Line 139:
	^--- always 04		^--- always 04
	^--- varies between 10, 11, 12, 13, 14, 15, 16, 17, 19, 1B		^--- varies between 10, 11, 12, 13, 14, 15, 16, 17, 19, 1B
	<pre>		</pre>

Bertrik Sikken: /* serial interface */

2024-04-25T20:23:31Z

serial interface

@@ Line 130: / Line 130: @@
 d 34 00 04 ??
 </pre>
 Each frame is 23 (x017) bytes long

Bertrik Sikken: /* serial interface */

2024-04-25T20:07:12Z

serial interface

← Older revision		Revision as of 20:07, 25 April 2024
Line 99:		Line 99:

	There is an internal serial interface (9600 bps).		There is an internal serial interface (9600 bps).
	When in bluetooth mode~~, but not connected yet~~, there is data going over this interface:		Use the following to configure the serial port on linux
			stty -F /dev/ttyUSB0 raw 9600 -echo
			Then dump using
			cat /dev/ttyUSB0 \|hexdump -C

			When in bluetooth mode, there is data going over this interface:
	<pre>		<pre>
	~~00000000~~ 01 fc 12 aa bb 10 05 3b 20 20 34 31 ~~2e 35~~ 64 42 ~~\|.......; 41.5dB\|~~		01 fc 12 13 aa bb 10 05 3b 20 20 34 34 2e 31 64 42 41 3d 34 00 04 14
	~~00000010~~ 41 3d 34 00 04 15 01 fc 12 aa bb 10 05 3b 20 20 ~~\|A=4..........; \|~~		01 fc 12 13 aa bb 10 05 3b 20 20 34 30 2e 34 64 42 41 3d 34 00 04 13
	~~00000020~~ 34 30 2e 33 64 42 41 3d 34 00 04 ~~12 01 fc 12 aa \|40.3dBA=4.......\|~~		01 fc 12 13 aa bb 10 05 3b 20 20 33 39 2e 30 64 42 41 3d 34 00 04 17
	~~00000030 bb 10 05 3b 20 20 33 39 2e 33 64 42 41 3d 34 00 \|...; 39.3dBA=4.\|~~		01 fc 12 13 aa bb 10 05 3b 20 20 33 38 2e 35 64 42 41 3d 34 00 04 1b
	~~00000040 04 1a~~ 01 fc 12 aa bb 10 05 3b 20 20 33 39 2e 30 ~~\|.........; 39.0\|~~		01 fc 12 13 aa bb 10 05 3b 20 20 33 38 2e 34 64 42 41 3d 34 00 04 1a
	~~00000050~~ 64 42 41 3d 34 00 04 17 01 fc 12 aa bb 10 05 3b ~~\|dBA=4..........;\|~~		01 fc 12 13 aa bb 10 05 3b 20 20 33 38 2e 38 64 42 41 3d 34 00 04 1e
	~~00000060~~ 20 20 33 39 2e 30 64 42 41 3d 34 00 04 17 01 fc ~~\| 39.0dBA=4.....\|~~		01 fc 12 13 aa bb 10 05 3b 20 20 33 39 2e 31 64 42 41 3d 34 00 04 18
	~~00000070~~ 12 aa bb 10 05 3b 20 20 33 38 2e 37 64 42 41 3d ~~\|.....; 38.7dBA=\|~~		01 fc 12 13 aa bb 10 05 3b 20 20 33 38 2e 39 64 42 41 3d 34 00 04 1f
	~~00000080~~ 34 00 04 1d 01 fc 12 aa bb 10 05 3b 20 20 33 38 ~~\|4..........;~~ 38\|		01 fc 12 13 aa bb 10 05 3b 20 20 33 39 2e 35 64 42 41 3d 34 00 04 1c
	~~00000090 2e 37~~ 64 42 41 3d 34 00 04 1d 01 fc 12 aa bb 10 ~~\|.7dBA=4.........\|~~		01 fc 12 13 aa bb 10 05 3b 20 20 33 39 2e 32 64 42 41 3d 34 00 04 19
	~~000000a0~~ 05 3b 20 20 33 38 2e 33 64 42 41 3d 34 00 04 ~~19 \|.; 38.3dBA=4...\|~~
	~~000000b0~~ 01 fc 12 aa bb 10 05 3b 20 20 33 38 2e 31 64 42 ~~\|.......; 38.1dB\|~~
	~~000000c0~~ 41 3d 34 00 04 17 01 fc 12 aa bb 10 05 3b 20 20 ~~\|A=4..........; \|~~
	~~000000d0~~ 33 37 2e 38 64 42 41 3d 34 00 04 1d 01 fc 12 aa ~~\|37.8dBA=4.......\|~~
	~~000000e0~~ bb 10 05 3b 20 20 33 38 2e 38 64 42 41 3d 34 00 ~~\|...; 38.8dBA=4.\|~~
	~~000000f0~~ 04 ~~1e 01 fc 12 aa bb 10 05 3b 20 20 33 38 2e 31 \|.........; 38.1\|~~
	</pre>		</pre>

	Dividing into "frames", starting with 01 fc 12 aa bb:<br>		Dividing into "frames", starting with 01 fc 12 aa bb:<br>
	<pre>		<pre>
	01 fc 12 aa bb 10 05 3b 20 20 34 31 ~~2e 35~~ 64 42 41 3d 34 00 04 15 "41.~~5dBA~~"		01 fc 12 13 aa bb 10 05 3b 20 20 34 34 2e 31 64 42 41 3d 34 00 04 14 => "44.1dBA"
	01 fc 12 aa bb 10 05 3b 20 20 34 30 2e 33 64 42 41 3d 34 00 04 12 "40.~~3dBA~~"		01 fc 12 13 aa bb 10 05 3b 20 20 34 30 2e 34 64 42 41 3d 34 00 04 13 => "40.4dBA"

	~~...~~		<---------header--------->
	01 fc 12 aa bb 10 05 3b ~~20 20 33 38 2e 38 64 42 41 3d 34 00 04 1e "38.8dBA"~~		01 fc 12 13 aa bb 10 05 3b
			<------------ascii------->
	~~header~~		X X . X d B A
	~~????????~~		<--- footer-->
	<----------~~ASCII~~--------->		3d 34 00 04 ??
	3d 34 00 04 1e
	</pre>		</pre>

	Each frame is 22 bytes long ~~(0x16)~~		Each frame is 23 (x017) bytes long

	~~Bytes:~~
	~~<pre>~~
	~~00: ??~~
	~~01: ??~~
	~~02: 'h' when hold is pressed~~
	~~03: AA always?~~
	~~04: BB always?~~
	~~05: 10~~
	~~06: 01, 05, ??~~
	~~07: ??~~
	~~08: 20 ascii~~
	~~09: 20 ascii~~
	~~0A: xx ascii~~
	~~0B: xx ascii~~
	~~0C: xx ascii~~
	~~0D: xx ascii~~
	~~0E: xx ascii~~
	~~0F: '='~~
	~~10: '3' when in slow mode, '4' when is fast mode~~
	~~11: ??~~
	~~12: ??~~
	~~13: ??~~
	~~14: ??~~
	~~15: ??~~
	~~</pre>~~

	==== BLE interface ====		==== BLE interface ====

Bertrik Sikken: /* serial interface */

2024-04-24T06:34:44Z

serial interface

← Older revision		Revision as of 06:34, 24 April 2024
Line 95:		Line 95:

	==== serial interface ====		==== serial interface ====
			Interpreting serial port data on Linux is not straightforward, since Linux treats a serial port as a terminal so by default it does terminal-specific stuff to the data.
			The data below may have been corrupted by the Linux tty subsystem trying to escape/unescape certain byte sequences.

	There is an internal serial interface (9600 bps).		There is an internal serial interface (9600 bps).
	When in bluetooth mode, but not connected yet, there is data going over this interface:		When in bluetooth mode, but not connected yet, there is data going over this interface: