View source for Kecheng KC-330B

{{Infobox sound level meter
| image               = [[File:Kecheng KC-330B.png|180px]]
| name                = Kecheng KC-330B
| status              = supported
| source_code_dir     = kecheng-kc-330b
| connectivity        = USB
| measurement_range   = 30dB - 130dB
| resolution          = 0.1dB
| accuracy            = 1.5dB
| frequency_weighting = A, C
| time_weighting      = F, S
}}

The '''Kecheng KC-330B''' is a sound level meter and data logger with USB connectivity.

See [[Kecheng KC-330B/Info]] for more details (such as '''lsusb -vvv''' output) about the device.

== Hardware ==

* [http://www.silabs.com/Support%20Documents/TechnicalDocs/C8051F32x.pdf Silicon Labs F320] 8-bit MCU with USB interface
* 2 X [http://www.sg-micro.com/f/productparticular.aspx?pid=60 SG Micro SGM8522] dual rail-to-rail op-amp, SGM8524 quad rail-to-rail op-amp
* [http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010828 Microchip 24LC512] 64KB EEPROM
* [http://www.ti.com/product/cd4053b Texas Instruments CD4053M] triple 2-channel multiplexer

== Photos ==
<gallery>
File:Kecheng KC-330B back.png|<small>Back of the device</small>
File:Kecheng KC-330B PCB LCD top.jpg|<small>PCB, top</small>
File:Kecheng KC-330B PCB bottom.jpg|<small>PCB, bottom</small>
File:Kecheng KC-330B PCB top.jpg|<small>PCB with LCD removed</small>
File:Kecheng KC-330B PCB top detail.jpg|<small>SGM8522/SGM8524</small>
File:Kecheng KC-330B F320.jpg|<small>Silicon Labs F320</small>
</gallery>

== Protocol ==

The host sends commands to the device via endpoint 2, and receives responses via endpoint 1. A command consists of a single byte, with the MSB (bit 7) cleared, followed by any arguments to the command. The response from the device consists of at least one byte: the command, with the MSB set.

{| border="0" width="100%" class="alternategrey sigroktable"
|-
! Command
! Response
! Description

|-
| 0x01
| 0x81
| '''Configure device''', 6 bytes payload:

|-
|
|
| style="padding: 0; font-size: smaller;" |
{| border="0" width="100%" style="margin: 0; border-collapse: collapse;" class="alternategrey"
|-
| style="width: 1em;" |
| style="width: 3em;" | 1
| Sample interval 0-6, representing 125ms, 500ms, 1s, 2s, 5s, 10s, 60s respectively.
|-
| style="width: 1em;" |
| style="width: 3em;" | 2
| Alarm low threshold
|-
| style="width: 1em;" |
| style="width: 3em;" | 3
| Alarm high threshold
|-
| style="width: 1em;" |
| style="width: 3em;" | 4
| Time weighting: 0=Fast, 1=Slow
|-
| style="width: 1em;" |
| style="width: 3em;" | 5
| Frequency weighting: 0=dBA, 1=dBC
|-
| style="width: 1em;" |
| style="width: 3em;" | 6
| Data source: 0=memory, 1=real time
|}

|-
| 0x02
| 0x82
| '''Identify''', response payload is length byte + device model (ASCII)

|-
| 0x03
| 0x83
| '''Set date and time''', 6 bytes payload:

|-
|
|
| style="padding: 0; font-size: smaller;" |
{| border="0" width="100%" style="margin: 0; border-collapse: collapse;" class="alternategrey"
|-
| style="width: 1em;" |
| style="width: 3em;" | 1
| Last two digits of year, e.g. 0x0d for 2013
|-
| style="width: 1em;" |
| style="width: 3em;" | 2
| Month, 1-12
|-
| style="width: 1em;" |
| style="width: 3em;" | 3
| Day of month, 1-31
|-
| style="width: 1em;" |
| style="width: 3em;" | 4
| Hours
|-
| style="width: 1em;" |
| style="width: 3em;" | 5
| Minutes
|-
| style="width: 1em;" |
| style="width: 3em;" | 6
| Seconds
|}

|-
| 0x04
|
| '''Check device status'''
|-
|
| 0x84
| Device is activated, i.e. logging to memory or live to PC ("log" on the display).
|-
|
| 0xa4
| Device is deactivated ("con" or "---" on the display).

|-
| 0x05
| 0x85
| '''Get stored measurement info''', response has 8 bytes payload:

|-
|
|
| style="padding: 0; font-size: smaller;" |
{| border="0" width="100%" style="margin: 0; border-collapse: collapse;" class="alternategrey"
|-
| style="width: 1em;" |
| style="width: 3em;" | 1-6
| Configuration settings of acquired data, same format as 0x01 command (except 0x11...)
|-
| style="width: 1em;" |
| style="width: 3em;" | 7-8
| Big-endian integer representing the number of stored measurements (32000 is the maximum).
|}

|-
| 0x06
| 0x86
| '''Get stored start date/time'''. Response has 6 bytes payload, same format as 0x03 command.

|-
| 0x07
| 0x87
| '''Get stored measurements''', 3 bytes payload:
|-
|
|
| style="padding: 0; font-size: smaller;" |
{| border="0" width="100%" style="margin: 0; border-collapse: collapse;" class="alternategrey"
|-
| style="width: 1em;" |
| style="width: 3em;" | 1-2
| Big-endian integer representing the sample offset, in blocks of 63 samples.
|-
| style="width: 1em;" |
| style="width: 3em;" | 3
| Number of samples to send. This is always the maximum, 0x3f, until the last chunk.
|}

|-
| 0x08
| 0x88
| '''Get live measurement''', response has 2 bytes payload: big-endian integer representing the dB value X 10

|}

[[Category:Device]]
[[Category:Sound level meter]]
[[Category:Supported]]