Making usable voltage meter for vmods and extreme benching

[TiN]

:welcome:

Maybe every overclocker had bad time, trying to measure some voltages with regular DMM, and due wrong location or shorts by big probe leads got dead hardware. Maybe I'm right to say that this is common in some way.

So I thought about this issues a bit, and decided to resolve that in some kind of special device, to act just as meter. Maybe I'm not best bencher, but I like to bench with tools that fit right way.

Also when be push videocards to their limits, usually time is short to take action, specially at LN2 temps. And having two DMMs to meter Vgpu and Vmem at same time not good idea, if to bench say 4 SLI rig, then every card will have four probes attached, that's 16 thick wires hanging in rig. :headshake:

Welcome two channel compact meter, with bright 4-digit LED screens for voltage readouts.

http://xdevs.com/kpc/varm/varm1.jpgP2http://xdevs.com/kpc/varm/varm0.jpg

Meter have 8-bit micro ATMEL ATmega8, with using of internal 10-bit SAR ADC for readouts, timers. USB bridge to UART from Silicon labs is used for easy interfacting with computer via virtual COM-port. This allows using device as logging system, to even see how voltage drops during bench.

http://xdevs.com/kpc/varm/varm2.jpg

http://xdevs.com/kpc/varm/varm3.jpg

http://xdevs.com/kpc/varm/varm4.jpg

With some firmware works it's possible to have this device metering current, resistance and temperature.

It powers from one 3-pin FAN connector on motherboard and take only 40mA of +12V rail.

P.S. I'm sure, nigel will post his love here soon :D j/k mate

[nigel]

^^ You read my mind Tin ;)

And where does it plug in to :s USB and reads it out true software? :)

[TiN]

I didn't soldered USB type-B socket when used that sample on photos above. USB connector is just between two screw blue connectors for wires. Take a look there ;) 2 big mount holes and 4 signaling for USB.

Here another sample and routing work.

http://xdevs.com/kpc/varm/varm.jpg

http://xdevs.com/kpc/varm/varm_pcb.png

Also, notice protection on each input, so if you done something bad - it's protected some kind.
Hooked to any videocard or motherboard, or any other VRM with voltage level up to 3V (for better accuracy, possible to extend range with some loss), with regular wires hooked to capacitors on VRM, and enjoy readout in realtime.

[nigel]

*Takes a closer look*
aah there it is :)

Intresting to see, I mean it seems simple enough (ehm relatively speaking ofcours) yet its the first time i've seen some one do it to keep an eye on voltages.
And wel probing a card ore doing it this way ^^ i would now what to choose :D

[TiN]

One more to say - very useful when adjusting voltages on OCP/OVP limited VRMs, you will exactly see when OVP/OCP latches. This thing helped me and T0lsty a lot to win UA stage of MOA 2010, mobo we used was tied to 1.7V OCP, and we were pushing clarkbar to it's limits, so it was everything about voltage. So thanks to this device, we managed to get very tight volts till OVP.

submission

This was that result, with photos attached. I think I can share this project freely to anybody, like on opensource terms here, exclusive for KPC :)

[Gomeler]

Could you open source the design? I'd be interested in assembling one of your many contraptions and this is one I could see myself using :up: The PCB designs with a part-list and simple instructions would be awesome.

[TiN]

Cool, I see you replying my crazy threads :D

Which format should I use for PCB? Gerber is ok?
Coz this is microcontroller based device - you will also need firmware and ISP pod to upload firmware into blank chip.

I only want reports and worklog in return for sharing everything related to this project.

[Cyph3r_Smurf]

opensource sounds great m8 :) Would like to make one big device that could measure voltage, resistance and temperature.

Then make it so big that I could use it for 4 way sli (8 displays with Vcore and Vmem) Then 1-2 displays for measure resistance with a couple of wires.
Then 4 displays for the temperature.

all in one big device with signs so i can see what is what. Quick and easy.

Would like to head how you have made this, then i could make the device on my own at school ;)

[Cyph3r_Smurf]

For the PCB format i just would like a format that either PCB Wizard or Eagle could read. I have to make the board on my own with a photoresistic print

[TiN]

I'm sorry smurf, but I'm going to kill your idea with necklace of displays. I'm actually own some device which can do all you described, but with one nice color TFT and two 5.25" space occupy. :D

Welcome, USB Device :)

http://xdevs.com/kpc/pics/XPKC.jpg

16bit color, 320x240, touchscreen, 8 voltage inputs, RTD temperature -200°C, 4 FAN control channels, 2 high-power control outputs, USB link to PC.

Frozen project atm. Anyway, it's offtopic here, whole another project, with uncomparable price :D

[Gomeler]

Cool, I see you replying my crazy threads :D

Which format should I use for PCB? Gerber is ok?
Coz this is microcontroller based device - you will also need firmware and ISP pod to upload firmware into blank chip.

I only want reports and worklog in return for sharing everything related to this project.

PCB printing and microcontroller programming isn't something I'm familiar with. I'll do a little research into this to see exactly what you're talking about :plol: I use a breadboard at home to build all my little toys :up:

[Dr.House]

opensource sounds really great, I´m also interesting on it for my own use :)

[stabias]

TiN, can you share pcb and firmware? I wonder of this device

[TiN]

Just let me some time, i need to setup server for that. I want to have comfortable interaction here.

[TiN]

BOM list of project

1 x ON 7805CG DA1 - LDO
1 x ATMEGA8L-8MI U1 - MCU
8 x BC817 SOT-23-3 VT1-VT8 - NPN BJT
2 x LED BQ-M51DRD Quad digit HL1-HL2 - LED displays
17 x SMD capacitor 0805 100nF
1 x Electrolytic capacitor 47uF 6.3V
1 x Electrolytic capacitor 10uF 16V
2 x SMD capacitor 0805 18pF
1 х IC SiLabs CP2103GM MLF28 - USB bridge
8 x SMD Diode 1206 BAS32 VD4-VD11 - Protection
2 x PLS-2 pin header 2.54mm
1 x 0805 LED SMD red - leds
1 х IC LM335Z, TO-92-3 - thermosensor
9 x SMD resistor 0603 1 kΩ
1 x SMD resistor 0603 5.1 kΩ
2 x SMD resistor 0603 7.5 kΩ
4 x SMD resistor 0603 10 kΩ
1 x SMD resistor 0603 30 kΩ
2 x SMD resistor 0603 100 kΩ
1 x SMD resistor 0603 470 Ω
1 x Variable resistor multiturn 3296W 10 kΩ
1 x Variable resistor multiturn 3296W 500 Ω
1 x Logic IC SN74HC595DW U2 SOW16 - Driver for leds
1 х Screw connector 2 pin 5mm spacing
1 х Screw connector 3 pin 5mm spacing
1 х USB Type-B angled connector for PCB - USB i/f conn
1 х 8MHz crystal oscillator

[dinos22]

I'm sorry smurf, but I'm going to kill your idea with necklace of displays. I'm actually own some device which can do all you described, but with one nice color TFT and two 5.25" space occupy. :D

Welcome, USB Device :)

http://xdevs.com/kpc/pics/XPKC.jpg

16bit color, 320x240, touchscreen, 8 voltage inputs, RTD temperature -200°C, 4 FAN control channels, 2 high-power control outputs, USB link to PC.

Frozen project atm. Anyway, it's offtopic here, whole another project, with uncomparable price :D
wow man i like this :clap:

[TiN]

Device in action shot again

http://xdevs.com/kpc/varm/varmx.jpg

hooked to EVGA Untouchabled GeForce GTX 285

[TiN]

Okay. Here we have trac project managment up and running

http://dev.xdevs.com/projects/varm - This is main project repository :)

There you will find project list (most are closed now, but maybe I will make all projects there as well, if this will be interested for general people).

There are small description wiki, timeline of changes,
roadmap for future development
All sources and schematic (via Repository section)
Anyone can leave ticket and task after free simple registration.

Enjoy. I'm here for feedback.

P.s. this is my homepc, so it may not run 24/7 atm. I need some hardware to aquire to setup dedicated home server machine on FreeBSD OS. My main project which feed me are runnin on another machine, so they are totally not linked to site above. :)

[carpo93]

Very nice idea man:)

[stabias]

TiN
should rev4 pcb be used? and schematic erv3?

[TiN]

Yes, latest revisions is what you see here on photos.

Actually there is even more new revision, but not covered in files yet.
Everything same, but added AD amplifier as voltage buffer , to isolate probes from meter.

[Chiller]

i whant one

[stabias]

do it:D

[nigel]

I love it Tin.
Going to have a talk to some people here.
Because flashing chips is not somthing that I can do :)

Thanks for sharing!

[TiN]

It's actually easy, and possible to do with just 5 wires and PC with LPT port :P

Chiller

Sorry, man, i have no spare parts for this :)

[Chiller]

damn, always bad luck lattlely :)

[TiN]

I did this project about 4 years ago :D

[TiN]

Small update :)

Made similar meter with bigger display and DIN-mount enclosure.

http://xdevs.com/kpc/varm/varmx2.jpg

w/o case:

http://xdevs.com/kpc/varm/varmx3.jpg

Fitted on breadboard, so easy to modify. Single-display this time.

More to come soon ;)

[s0lid]

TiN the dev.xdevs.com isn't replying.
I'd like to grab the schemastic and source code from there :|

[0skill]

i`ve got the whole package
i`ve downloaded it 3 month ago but i cant open PCB and SCH files dont know why
tried it with Express PCB and PCB Wizard3 but no way
if you want it i`ll upload the package to rapidshare or anything else
mybe you can help me to open this files

[s0lid]

Sure i can have a look at it =)

[0skill]

http://www.speedshare.org/download.php?id=D88EBCFE11

[TiN]

CAD files are in Accel P-CAD 2006 format and can be opened only by it.

[rbuass]

OMG
I imagine that really nice to have a Skill to do this kind of work.
Congratz

[Hellshealer]

ima have my sister have a look at this for me and see what she can do. she is a radio tech for a State wide railway company here in Aus and is pretty keen with a soldering iron and basic schematics.

cheers tin

[s0lid]

TiN, I'm currently designing pcb for the varm schematic i got...
There is this tv3_10_10 connector. What is it used for?

[RRainbo]

If I looked right it's for input measured voltage

[s0lid]

Oh why indeed.
So the KN1 and KN2 are jumpers?
As there's pulldown resistors on the data line and vcc on pin1.

[RRainbo]

Yes it looks like jumpers or buttons
I checked code and they are not used. It is just on the beginning set as input but also turn off external interrupt and don't see it tested in code so they are not used.