Difference between revisions of "UNI-T UT372"

From sigrok
Jump to navigation Jump to search
(Fix broken link)
(UT372 is supported.)
Line 2: Line 2:
| image          = [[File:UT372_front.jpg|60px]]
| image          = [[File:UT372_front.jpg|60px]]
| name            = UNI-T UT372
| name            = UNI-T UT372
| status          = in progress
| status          = supported
| source_code_dir =  
| source_code_dir = uni-t-dmm
| counts          = 99999
| categories      =  
| connectivity    = USB
| connectivity    = USB
| measurements    = rpm, counts
| features        =
| website        = [http://uni-trend.com/UT372.html uni-trend.com]
| website        = [http://uni-trend.com/UT372.html uni-trend.com]
}}
}}
Line 14: Line 18:
* [http://www.silabs.com/Support%20Documents/TechnicalDocs/C8051F313-short.pdf Silicon Labs C8051F313] MCU
* [http://www.silabs.com/Support%20Documents/TechnicalDocs/C8051F313-short.pdf Silicon Labs C8051F313] MCU
* [http://www.goldenviewdisplay.com/pdf/LCD_controllers/ht1621.pdf Holtek HT1621B] LCD controller
* [http://www.goldenviewdisplay.com/pdf/LCD_controllers/ht1621.pdf Holtek HT1621B] LCD controller
* [[WCH_CH9325 | WCH CH9325]] USB UART interface
* [[WCH CH9325]] USB UART interface


The unit includes a built in laser pointer for aiming at a reflective target, and a tripod fitting to allow stable mounting.
The unit includes a built in laser pointer for aiming at a reflective target, and a tripod fitting to allow stable mounting.
Line 21: Line 25:


<gallery>
<gallery>
File:UT372_front.jpg
File:UT372_front.jpg|<small>Device, front</small>
File:UT372_back.jpg
File:UT372_back.jpg|<small>Device, back</small>
File:UT372_pcb.jpg
File:UT372_pcb.jpg|<small>PCB, top</small>
</gallery>
</gallery>


Line 38: Line 42:
=== LCD character lookup ===
=== LCD character lookup ===


{| border="0" class="alternategrey sigroktable sortable"
{| border="0" style="font-size: smaller" class="alternategrey sigroktable sortable"
|-
|-
! style="width: 5em; text-align: left;" | String
! style="width:5em; text-align: left;" | String
! style="text-align: left;" | Hex Byte
! style="text-align: left;" | Hex byte
! style="text-align: left;" | Character
! style="text-align: left;" | Character
|-
|-
Line 92: Line 96:
=== Other display segments ===
=== Other display segments ===


{| border="0" class="alternategrey sigroktable sortable"
{| border="0" style="font-size: smaller" class="alternategrey sigroktable sortable"
|-
|-
! style="width: 5em; text-align: left;" | Bit (LSB #0)
! style="width:5em; text-align: left;" | Bit&nbsp;(LSB&nbsp;#0)
! style="text-align: left;" | First byte
! style="text-align: left;" | First byte
! style="text-align: left;" | Second byte
! style="text-align: left;" | Second byte
Line 139: Line 143:
[[Category:Device]]
[[Category:Device]]
[[Category:Tachometer]]
[[Category:Tachometer]]
[[Category:In progress]]
[[Category:Supported]]

Revision as of 17:36, 26 March 2015

UNI-T UT372
UT372 front.jpg
Status supported
Source code uni-t-dmm
Counts 99999
Connectivity USB
Measurements rpm, counts
Website uni-trend.com

The UNI-T UT372 is a digital tachometer with USB connectivity.

Hardware

The unit includes a built in laser pointer for aiming at a reflective target, and a tripod fitting to allow stable mounting.

Photos

Protocol

The MCU transmits serial data to the CH9325 at 2400 baud. A packet is 27 bytes of ASCII data ending in CR, LF.

The packet is processed to turn it into a valid hex string - any character with an ASCII value above 0x39 is shifted up by 7 characters, putting it into the range 'A' to 'F'.

The first character seems to be ignored. The next 5 pairs of characters represent the RPM (least significant digit first). The next 5 pairs of characters represent the time (least significant digit first). The final 2 pairs of characters represent the remaining segments of the display.

Each pair of characters, when interpreted as a single hex byte, is a bitfield representing the on/off state of segments on the display. A look-up table is provided below. Setting the most significant bit indicates that a decimal point is placed after that digit.

LCD character lookup

String Hex byte Character
"7;" 0x7B 0
"60" 0x60 1
"5>" 0x5E 2
"7<" 0x7C 3
"65" 0x65 4
"3=" 0x3D 5
"3?" 0x3F 6
"70" 0x70 7
"7?" 0x7F 8
"7=" 0x7D 9
"0;" 0x0B L

Other display segments

Bit (LSB #0) First byte Second byte
0 - RPM
1 BATT COUNT
2 HOLD -
3 - -
4 LED MAX
5 - MIN
6 - AVE
7 - -

Resources