AN8008 US $19, 9999count, 1uV, 0.01uA, 0.01Ohm, 1pF resolution meter

[plazma]

I added RANGE and REL buttons to my AN8002. Let see if button modification is possible with the AN8008.

What kind of switches have used? Isn't the rubber buttons to soft for normal push buttons?

I used these switches
https://www.arrow.com/en/products/evp-ayf1ba/panasonic

I used 1mm thick PCB for the button separator. I'll take more pictures when I modify my second unit and the AN8008.

[Crumble]

Wow, that's briliant! Well done. Please do share the information on how you did this, I think a lot of people would be thankful.

[RedSky]

Slighty off topic.   I note what looks like the AN8002 meter on the front of the new Altronics Engineering Catalogue.. it's going mainstream 

[BroMarduk]

There is a new model look a like : SURPEER AV4     it is a 20000 counts model ? maybe worth checking ? sure it is not a 20$ meter ...

on Ebay: http://www.ebay.com/itm/digital-multimeter-true-rms-4-1-2-voltmeter-with-auto-range-multi-meter/112444656128?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D2%26asc%3D41376%26meid%3Dbdba934ac7de4c11bf5d7231a7c8164c%26pid%3D100005%26rk%3D4%26rkt%3D6%26sd%3D152355178736

I received an HY-19E from China (Banggood - 39.99 USD) that appears to be the same model (except in green).  Haven't tested it yet, but will soon.   Build quality is on par with the larger Aneng meters - which means just slightly below average.

[plazma]

Those meters may have a different IC like in AN8004. 6000 count is usually the clue for the DTM0660 IC.

[floobydust]

plazma, I'm not sure you can access the other pushbutton switch lines on AN8008. Let us know how it's going.

When I looked at the AN8008 circuit, the pushbuttons go to GND instead of a matrix.
The DMM IC/MCU supports a scanned 2x3 matrix for up to 6 pushbuttons + BL to GND for total 7 buttons as per pic.

The AN8008 firmware might still allow the other pushbuttons but I could not see one or two MCU lines for them.

RANGE/BL goes to GND. Is PT1.0? Not sure about PT3.7 I did not see it.
SEL/HOLD goes to GND; Is PT3.5? Not sure about PT1.1 I did not see it.

REL/RS232 and HOLD/Backlight we have PT1.5 from the EEPROM pin 5.

[Gandalf_Sr]

Just got back home after travelling, my "AN8008" was a stupid plastic junk item and a BS Chinglish note - I'll be complaining to Amazon tomorrow I think.

[MacMeter]

Just got back home after travelling, my "AN8008" was a stupid plastic junk item and a BS Chinglish note - I'll be complaining to Amazon tomorrow I think.

Read my post and others response on previous page concerning the same issue.

[Gandalf_Sr]

Just got back home after travelling, my "AN8008" was a stupid plastic junk item and a BS Chinglish note - I'll be complaining to Amazon tomorrow I think.

Read my post and others response on previous page concerning the same issue.

Yeah, I saw that - Allouete was the shipper - I have complained and asked for a refund - we will see what happens; if I get a refund, I think I'll order the Tougs M103 instead, it could be here as soon as Sunday if I order it today and it looks like it's the exact same meter although it only comes with basic leads.

[tooki]

It sounds like many multimeter customers want the meter to read 0.000mV if the leads are shorted. The manufacturers do not want to have to explain offset voltages and thermal voltages to complaining customers I guess.

It would be great if there is a way to turn this dead zone off.

Yup, same with most of the Chinese digital panel meters, making them useless for many applications....

This is part of the reason I am making my own panel meter of sorts, for a power supply, using an arduino, a display, and the awesome INA226. mV resolution full-scale at 120Hz update rate on the slowest speed, and agrees within 3 counts of a keithley 2015 bench meter!

[kalel]

There is a new model look a like : SURPEER AV4     it is a 20000 counts model ? maybe worth checking ? sure it is not a 20$ meter ...

on Ebay: http://www.ebay.com/itm/digital-multimeter-true-rms-4-1-2-voltmeter-with-auto-range-multi-meter/112444656128?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D2%26asc%3D41376%26meid%3Dbdba934ac7de4c11bf5d7231a7c8164c%26pid%3D100005%26rk%3D4%26rkt%3D6%26sd%3D152355178736

I received an HY-19E from China (Banggood - 39.99 USD) that appears to be the same model (except in green).  Haven't tested it yet, but will soon.   Build quality is on par with the larger Aneng meters - which means just slightly below average.

Let us know how it is. 20000 count.

[floobydust]

...   Virtually no chance this thing has a 13+bit ADC in it... yet it's trying to do 10,000 resolution has to be a fair amount of averaging going on.

The resolution is already here for DMM's.
The Hycon HY12P65 DMM IC has ?? A/D 18-bit at medium sample rate for 99,999 counts( bi-polar) capability.
Dream Tech's firmware is chopping this down, because crippling features is needed I guess. The 4-digit LCD display is the limiting factor to 9,999 counts.
That built-in MCU limiting factor is its 4MHz clock and 6KB code-space is pretty tight, although what's a little assembly language...

I'm tempted make a DMM with HY3131 the analog front end with 24-bit A/D. HY3130 is 16-bit A/D for 50,000 count applications.

I'll bet the AN8002, AN8004 use the same DMM IC and firmware. People have upped the "max. counts" EEPROM number and accessed the higher resolution.
But you have to recalibrate and tronde says some True-RMS hassles. There's a few other EEPROM settings to play with.
Probably the internal voltage reference is poor and so the AN8008 went to an external Vref IC.

[crazyguy]

...   Virtually no chance this thing has a 13+bit ADC in it... yet it's trying to do 10,000 resolution has to be a fair amount of averaging going on.

The resolution is already here for DMM's.
The Hycon HY12P65 DMM IC has ?? A/D 18-bit at medium sample rate for 99,999 counts( bi-polar) capability.
Dream Tech's firmware is chopping this down, because crippling features is needed I guess. The 4-digit LCD display is the limiting factor to 9,999 counts.
That built-in MCU limiting factor is its 4MHz clock and 6KB code-space is pretty tight, although what's a little assembly language...

I'm tempted make a DMM with HY3131 the analog front end with 24-bit A/D. HY3130 is 16-bit A/D for 50,000 count applications.

 
I'll bet the AN8002, AN8004 use the same DMM IC and firmware. People have upped the "max. counts" EEPROM number and accessed the higher resolution.
But you have to recalibrate and tronde says some True-RMS hassles. There's a few other EEPROM settings to play with.
Probably the internal voltage reference is poor and so the AN8008 went to an external Vref IC.

In practical, due to the noise and distortion in the ADC circuity, the ENOB (effective number of bits) must be less than ADC specified number of bits.

Resolution vs. ENOB – Still Hazy After All These Years
http://www.analog.com/en/analog-dialogue/raqs/raq-issue-90.html

HY12P65 ENOB Test Tool User Manual
http://www.hycontek.com/wp-content/uploads/APD-DMM004_EN.pdf

[floobydust]

HY12P6x ENOB is given as 19-bit and Eval board has 6-digit LCD. I think the test software is to verify performance, do FFT of the noise.

Hard to know what the signal/noise ratio of the input amp, A/D, reference etc. will be and what you can improve with digital filtering and over-sampling, noise shaping.
I guess that can improve ENOB.

So how many usable A/D bits do we have? 

[crazyguy]

HY12P6x ENOB is given as 19-bit and Eval board has 6-digit LCD. I think the test software is to verify performance, do FFT of the noise.

Hard to know what the signal/noise ratio of the input amp, A/D, reference etc. will be and what you can improve with digital filtering and over-sampling, noise shaping.
I guess that can improve ENOB.

So how many usable A/D bits do we have?

you modified the decoupling capacitors on your meter, already improved the SNR -> improved the ENOB a little bit.

[Gandalf_Sr]

I got a reply from Allouete after I asked them to refund my money for the AN8008 ordered July 15th, they say the meter is in transit and sent me a tracking number that USPS tracking says...

Your item arrived at our USPS facility in LOS ANGELES CA INTERNATIONAL DISTRIBUTION CENTER on August 3, 2017 at 1:45 pm. The item is currently in transit to the destination

with an expected delivery date of Aug 8th.

Allouete has asked me to wait 4 more days which seems worth doing as long as the tracking number is actually for my meter; they won't be getting a 5-star rating or any other business from me though.

[MacMeter]

I got a reply from Allouete after I asked them to refund my money for the AN8008 ordered July 15th, they say the meter is in transit and sent me a tracking number that USPS tracking says...

Your item arrived at our USPS facility in LOS ANGELES CA INTERNATIONAL DISTRIBUTION CENTER on August 3, 2017 at 1:45 pm. The item is currently in transit to the destination

with an expected delivery date of Aug 8th.

Allouete has asked me to wait 4 more days which seems worth doing as long as the tracking number is actually for my meter; they won't be getting a 5-star rating or any other business from me though.

My seller "EasyDeal88", asked me to wait, I asked for an actual shipping tracking number, and was promptly sent one, guess what, just a "label created", that was days a go. I'm not in a hurry, and I can always get a refund from Amazon if I don't get it, for $23 the sellers  know this as well.

[Gandalf_Sr]

My seller "EasyDeal88", asked me to wait, I asked for an actual shipping tracking number, and was promptly sent one, guess what, just a "label created", that was days a go. I'm not in a hurry, and I can always get a refund from Amazon if I don't get it, for $23 the sellers  know this as well.

Interesting, I'm not worried about the refund, I know Amazon will intervene if I ask them too, I'm giving the seller a few more days because the original listing said it could arrive between Aug 4-25 but it is annoying that you can't see from the Amazon web site that the item will ship from China. It's dopey that they shipped a plastic bag to me as a 'gift', better to send me the item I ordered a few days later.

Also, I can see the AN8008 listed on banggood.com right now  for $17 shipped.

[plazma]

I tested some button options for the AN8008.
SET/HOLD is PT1.0 - BAT-
RANGE/BackLight is PT1.2 - BAT-

These did not have any effect.
PT1.0 - PT1.1
PT1.0 - PT1.2
PT1.0 - SDA
PT1.1 - BAT-
PT1.1 - PT1.2
PT1.1 - SDA
PT1.2 - SDA

So no button hacks found. There are still some possible pins but I think all other button options are disabled in FW.
Only temperature  probe is hackable.

IMHO AN8002 is a better option for general use and AN8008 is only better in those small ranges.

[Fungus]

IMHO AN8002 is a better option for general use and AN8008 is only better in those small ranges.

Yep.

And the AN860B+ has all the features of both of those plus a few more (e.g. REL, MIN/MAX) for about $2 more

[plazma]

IMHO AN8002 is a better option for general use and AN8008 is only better in those small ranges.

Yep.

And the AN860B+ has all the features of both of those plus a few more (e.g. REL, MIN/MAX) for about $2 more

I paid 12€ each for my AN8002 units. AN860B+ got more features but is regular size.

[floobydust]

I tested some button options for the AN8008.... ... no button hacks found....

No "eggs" as the chinese say in the AN8008
Only simple hack is to enable the temperature function.

I put a scope on the pushbutton scan lines and no pulses. They are only on/off so the AN8008 has unique firmware. I thought it would be the same as the generic DMM IC family, with EEPROM enabling more digits.

The AN8002 is the mother of the AN8008, look at the PCB.
Should be able to add external reference IC to AN8002 and not sure how it would do at 9,999 counts.

[Gandalf_Sr]

Can someone point me to where the information is on how to get temperature added to the AN8008?

Mine is apparently in Michigan now, about 40 miles away from me as of 10:51pm yesterday EST.  Might arrive today but more likely Monday; maybe never.

[matura713]

Can someone point me to where the information is on how to get temperature added to the AN8008?

https://www.eevblog.com/forum/testgear/an8008-us-$19-10000count-1uv-0-01ua-0-01ohm-resolution-meter/msg1258876/#msg1258876

[floobydust]

Can someone point me to where the information is on how to get temperature added to the AN8008?

https://www.eevblog.com/forum/testgear/an8008-us-$19-10000count-1uv-0-01ua-0-01ohm-resolution-meter/msg1258876/#msg1258876

I think that post is wrong, he did not add it the "mA" function but V function.

Instead I  added it to the mV function:
* EEPROM address 0xAC changed from 0x00 to 0x13 adds °C to mV function
* EEPROM address 0xBC changed from 0x00 to 0x15 adds °F to mV function

Purple highlight in attached partial EEPROM (feature map) dump.
The rotary switch also supports temp measurement but that position is missing.