Author Topic: EEVblog #1238 - Vion: The World's Worst Multimeter  (Read 3034 times)

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Offline German_EE

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Re: EEVblog #1238 - Vion: The World's Worst Multimeter
« Reply #25 on: August 17, 2019, 04:49:32 pm »
I was thinking about the LED thing, and yes, I know that they got it badly wrong. How about this for an idea:

RED          Voltage 1v-2v   Single 1.5v cells
ORANGE  Voltage 8v-12v  9v cells and car electrics
YELLOW   Voltage 20v-30v  Truck electrics
GREEN     Voltage 45v-55v  Telecoms
BLUE        Voltage over 100v

Blinking LED = AC

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Offline Fungus

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Re: EEVblog #1238 - Vion: The World's Worst Multimeter
« Reply #26 on: August 17, 2019, 05:54:02 pm »
I was thinking about the LED thing, and yes, I know that they got it badly wrong. How about this for an idea:

RED          Voltage 1v-2v   Single 1.5v cells
ORANGE  Voltage 8v-12v  9v cells and car electrics
YELLOW   Voltage 20v-30v  Truck electrics
GREEN     Voltage 45v-55v  Telecoms
BLUE        Voltage over 100v

Oh, yeah. Now it's a device I want to own.

(not)

I dunno. When I want to measure something I don't want to have to dismantle it and sit for half an hour while it charges the battery, then spend 10 minutes downloading an app, creating an online account and trying to pair it to my phone. Not when AA batteries exist and custom LCD screens are cheaper then bluetooth modules.

(What if the whole family use it? Do they all have to have separate accounts?)

I imagine V2 of this will have WiFi and post the readings directly to your Facebook timeline. :popcorn:
 

Offline Zbig

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Re: EEVblog #1238 - Vion: The World's Worst Multimeter
« Reply #27 on: August 17, 2019, 06:03:49 pm »
I was thinking about the LED thing, and yes, I know that they got it badly wrong. How about this for an idea:

RED          Voltage 1v-2v   Single 1.5v cells
ORANGE  Voltage 8v-12v  9v cells and car electrics
YELLOW   Voltage 20v-30v  Truck electrics
GREEN     Voltage 45v-55v  Telecoms
BLUE        Voltage over 100v

Blinking LED = AC

How about that: an LCD displaying an actual number which directly corresponds to the value being measured! Radical, I know ;D It's cheap, too. Also, unloaded (open circuit) voltage is pretty much meaningless when assessing state of charge of most consumer primary batteries.
 

Online NiHaoMike

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Re: EEVblog #1238 - Vion: The World's Worst Multimeter
« Reply #28 on: August 18, 2019, 01:37:53 am »
Anyway, it looks like mm have stopped production, its marked as sold out on their page and "obsolete" on digikey. I have one and its very useful for remote logging, but not day to day use.
Having a rechargeable version would be good but: it would cost a lot more, and would have been hell to pass certifications (as they stated any cover or port protection has to be open during high voltage testing, this is why the SD slot had to be covered up).
Where I think they really failed is their insistence on using an oddball BLE adapter to connect to it using Python instead of the standard Bluetooth chip that is in almost every modern connected device nowadays. I would use my Mooshimeter a lot more if I could bring a measurement window on my PC screen, complete with the ability to log measurements as needed. (Workaround: Nexus 7 with failed touch screen remote controlled from PC using scrcpy.)
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Offline David Hess

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Re: EEVblog #1238 - Vion: The World's Worst Multimeter
« Reply #29 on: August 18, 2019, 03:41:00 am »
How about that: an LCD displaying an actual number which directly corresponds to the value being measured! Radical, I know ;D It's cheap, too. Also, unloaded (open circuit) voltage is pretty much meaningless when assessing state of charge of most consumer primary batteries.

There are lots of good and inexpensive pen style multimeters although I did a search and none that I found included Bluetooth.

The unloaded voltage for most primary cells actually is a pretty good measurement of cell state if you are testing to see if something failed due to low charge.  1.2 volts on an alkaline cell unambiguously means depleted.
 
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Offline Fungus

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Re: EEVblog #1238 - Vion: The World's Worst Multimeter
« Reply #30 on: August 18, 2019, 12:43:09 pm »
[ Specified attachment is not available ]
How about that: an LCD displaying an actual number which directly corresponds to the value being measured! Radical, I know ;D It's cheap, too. Also, unloaded (open circuit) voltage is pretty much meaningless when assessing state of charge of most consumer primary batteries.
The unloaded voltage for most primary cells actually is a pretty good measurement of cell state if you are testing to see if something failed due to low charge.  1.2 volts on an alkaline cell unambiguously means depleted.

These cost $2 and don't need no steenkin' bluetooth (or prior-knowledge about "primary cell voltage").

Just sayin'  :popcorn:

« Last Edit: August 18, 2019, 12:44:50 pm by Fungus »
 

Offline David Hess

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Re: EEVblog #1238 - Vion: The World's Worst Multimeter
« Reply #31 on: August 18, 2019, 10:23:47 pm »
(Attachment Link)
The unloaded voltage for most primary cells actually is a pretty good measurement of cell state if you are testing to see if something failed due to low charge.  1.2 volts on an alkaline cell unambiguously means depleted.

These cost $2 and don't need no steenkin' bluetooth (or prior-knowledge about "primary cell voltage").

Yes, but using an expensive and inscrutable to the uninitiated multimeter to test 10 cent batteries makes me a wizard.

Incidentally, using the thermocouple temperature probe on the same multimeter for cooking means my friends never ask me to cook anymore.
 
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Offline thm_w

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Re: EEVblog #1238 - Vion: The World's Worst Multimeter
« Reply #32 on: August 19, 2019, 08:13:43 pm »
Where I think they really failed is their insistence on using an oddball BLE adapter to connect to it using Python instead of the standard Bluetooth chip that is in almost every modern connected device nowadays. I would use my Mooshimeter a lot more if I could bring a measurement window on my PC screen, complete with the ability to log measurements as needed. (Workaround: Nexus 7 with failed touch screen remote controlled from PC using scrcpy.)

Damn I didn't even think about that, being able to access it via PC would have been a huge bonus. I see some options for linux but they are not exactly plug and play (https://github.com/ghtyrant/libsooshi).

I was thinking about the LED thing, and yes, I know that they got it badly wrong. How about this for an idea:

RED          Voltage 1v-2v   Single 1.5v cells
ORANGE  Voltage 8v-12v  9v cells and car electrics
YELLOW   Voltage 20v-30v  Truck electrics
GREEN     Voltage 45v-55v  Telecoms
BLUE        Voltage over 100v

Blinking LED = AC

That won't work because then you can't tell if a battery is "good" or not, unless you had multiple LEDs which just makes it confusing. Emphasis on the quotes.

Has to be something like:
0.8-1.1V = red, 1.1-1.7V = green
7-8.5V = red, 8.5-9.5V = green, etc
 

Offline amyk

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Re: EEVblog #1238 - Vion: The World's Worst Multimeter
« Reply #33 on: August 20, 2019, 02:20:11 am »
I don't see a separate ADC, so it's probably using the 12-bit one in the nRF52832 itself. No obvious voltage reference either, might just be using the CPU VDD itself. Even I know that's a big no-no, and I don't do analog stuff much either.

Even a '7106 out of a $2 830-style meter would be far more accurate.

This is what happens when non-engineers design products... |O
 

Offline VK3DRB

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Re: EEVblog #1238 - Vion: The World's Worst Multimeter
« Reply #34 on: August 22, 2019, 12:26:09 pm »
Yep, it is pretty bad. I suspect Vion has no sensible design process, like design reviews, design verification testing, risk analysis etc. Typically, a good electronic engineer would spend at least half of his design effort focused on mitigating product failures and regulatory compliance requirements like safety, EMC etc. A good paradigm for an electronic design engineer is to assume everyone is out to sue him or his company and if anyone dies due to his design, he will be in jail sharing a cell with Big Bubba. 

Some major companies have also made ridiculous products. One example is the infamous IBM backup/restore utility for IBM DOS to backup user files and programs onto diskette and restore them later. They made it so that you can only restore you files on the SAME DOS version. So if you were upgrading from DOS 4.0 to Dos 4.1, the tool simply did not restore (after you had formatted the HDD), but shows an error message on the screen stating wrong DOS version. EPIC FAIL! XCOPY was an alternative, but you have to make sure you has gotten everything manually including CONFIG.SYS and AUTOEXEC.BAT, and the average dingbat PC user would not have heard of XCOPY.
« Last Edit: August 22, 2019, 12:31:33 pm by VK3DRB »
 

Offline nctnico

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Re: EEVblog #1238 - Vion: The World's Worst Multimeter
« Reply #35 on: August 23, 2019, 10:54:57 am »
I don't see a separate ADC, so it's probably using the 12-bit one in the nRF52832 itself. No obvious voltage reference either, might just be using the CPU VDD itself. Even I know that's a big no-no, and I don't do analog stuff much either.
You don't always need a voltage reference for doing precision stuff with an ADC in a microcontroller. The reference can also be a precision resistor.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline thm_w

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Re: EEVblog #1238 - Vion: The World's Worst Multimeter
« Reply #36 on: August 23, 2019, 09:29:39 pm »
You don't always need a voltage reference for doing precision stuff with an ADC in a microcontroller. The reference can also be a precision resistor.

Could you give an example please? I assume not multi-slope or similar.
 

Offline YU7C

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Re: EEVblog #1238 - Vion: The World's Worst Multimeter
« Reply #37 on: September 27, 2019, 09:11:51 am »
You think a $2 multimeter is bad?
A review of the Kickstarter & Indiegogo Vion bluetooth multimeter that promised the world.
Grab your popcorn for a master class in idiotic product design.



Sorry Dave, after this review I can't trust anymore on your expertise of products!

Until you start wearing a mustache!    :-DD

 


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