Difference between revisions of "Victor 70C"

From sigrok
Jump to navigation Jump to search
Line 28: Line 28:
== Protocol ==
== Protocol ==


14 bytes polled, likely based on the LCD segments.
The device registers on the USB host as a HID-class device. The protocol payload is 14 bytes of data which can be read from endpoint 1, at no more than 1 Hz.
 
The 14-byte chunk is somewhat obfuscated. To deobfuscate, subtract the ASCII value of the following string from each of the 14 bytes in turn: '''<code>jodenxunickxia</code>'''. Then reshuffle the bytes into different positions, according to the following table:
 
{| border="0" style="font-size: smaller" class="alternategrey sortable sigroktable"
|-
!Original
! Final
 
|-
| 0
| 6
 
|-
| 1
| 13
 
|-
| 2
| 5
 
|-
| 3
| 11
 
|-
| 4
| 2
 
|-
| 5
| 7
 
|-
| 6
| 9
 
|-
| 7
| 8
 
|-
| 8
| 3
 
|-
| 9
| 10
 
|-
| 10
| 12
 
|-
| 11
| 0
 
|-
| 12
| 4
 
|-
| 13
| 1
 
|}


== Resources ==
== Resources ==

Revision as of 11:50, 18 August 2012

Victor 70C

The Victor 70C is a 4000 counts, CAT II handheld digital multimeter with USB connectivity. It is also sold as the EZA EZ-735

See Victor 70C/Info for more details (such as lsusb -vvv output) about the device.

Hardware

Photos

  • Device, front

  • PCB, front

  • PCB, bottom

  • DMM/LCD chip

  • NXP HEF4066BT

  • Microchip TC7660E

  • TI 27L2C

  • LCD

Protocol

The device registers on the USB host as a HID-class device. The protocol payload is 14 bytes of data which can be read from endpoint 1, at no more than 1 Hz.

The 14-byte chunk is somewhat obfuscated. To deobfuscate, subtract the ASCII value of the following string from each of the 14 bytes in turn: jodenxunickxia. Then reshuffle the bytes into different positions, according to the following table:

Original Final
0 6
1 13
2 5
3 11
4 2
5 7
6 9
7 8
8 3
9 10
10 12
11 0
12 4
13 1

Resources

Retrieved from "https://sigrok.org/w/index.php?title=Victor_70C&oldid=3200"