VICHY VC99 going BlueToo Forget optical separation

Upon discovering serial on VC99 & voltmeter software/mods,
I have darker plans! [todo: decoding & displaying it in a browser]

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Software: - Linux/OSX, no idea about windows software, let us know, will add to the list

Follow the instructions and solder the wires, install software and test it via serial first - many links at the end of the page like:


Be aware of copy cats


Decoding of serial data is on page 30, there is also a pin for BackLight Form

Adobe Portable Document Format - 1.38 MB - 01/07/2018 at 20:50


  • 1 × HC-05 or HC-06, later maybe ble HM-10 Or any other serial Bluetooth or BLE

  • Got the data, da-bu-dy-de-code!

    Gintaras Valatka05/03/2017 at 03:55 0 comments

    After renaming HC-05 to VC99, bluetooth serial port in OSX was /dev/cu.VC99-DevB

    By launching serial motor, Arduino IDE connects to Bluetooth, HC-05 switch from fast to slow blinking indicating connection. QtDmm was not able to establish connection to HC-09. It would say connecting, blink rate would change, but did not work out of the box

    Switch on rs232 on VC99 now or even before establishing connection

    Process incoming data, log, display in a browser.. todo decode the rest of the.

    The digits and polarity clearly visible, need to work out the rest of the bytes, suggested protocol was VC820 14 byte binary, this might be a good start

  • Open & Solder

    Gintaras Valatka04/21/2017 at 18:40 0 comments

    Maybe I should have soldered to the pcb, in case of an accident...
    As seen in the last photo, there are 4 holes for holding the dial, do not undo them to keep the dial in place :D
    Cleaning the contacts could also be good a idea, since it is open :D

View all 2 project logs

  • 1
    Step 1

    The HC-05 that I have comes with a button and EN pin. Plugged EN pin to +5v and held the button while powering the module to enter AT mode


    SET THE SPEED TO: AT+UART=2400,0,0

    If you wanted to change the name, you would type:

    Exit AT mode and fire it up! :D

    More AT commands:

View all instructions

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