EEVblog > EEVblog Specific

EEVblog #1238 - Vion: The World's Worst Multimeter

<< < (7/9) > >>

Fungus:
[attachimg=2]
--- Quote from: David Hess on August 18, 2019, 03:41:00 am ---
--- Quote from: Zbig on August 17, 2019, 06:03:49 pm ---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.
--- End quote ---
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.

--- End quote ---

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

Just sayin'  :popcorn:

[attachimg=1]

David Hess:

--- Quote from: Fungus on August 18, 2019, 12:43:09 pm ---[attachimg=2]
--- Quote from: David Hess on August 18, 2019, 03:41:00 am ---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.
--- End quote ---

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

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.

thm_w:

--- Quote from: NiHaoMike on August 18, 2019, 01:37:53 am ---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.)

--- End quote ---

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).


--- Quote from: German_EE 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

--- End quote ---

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

amyk:
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

VK3DRB:
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.

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version