What?? New Aneng AN888S combines Multimeter, Bluetooth speaker, and clock

[Fungus]

They must be doing something-- After all 14-bit is  0 to 16,383  or about +/- 8191

I don't think negative voltage measurements work the way you think they do. 

[Andrew_Debbie]

How does it work?  I know very little about DMM chips  and not enough about digital signal processing.

'd be surprised if the AN-888S isn't doing averaging.    Other than that, I can guess, but my guess is probably wrong.

[Fungus]

How does it work?  I know very little about DMM chips  and not enough about digital signal processing.

For a negative voltage it probably swaps the inputs around.

Why waste a whole bit of your ADC?

[floobydust]

There's some kind of conspiracy with these DreamTech DMM IC's. I think DreamTech just writes the OTP firmware for the Hycon H08 mixed-signal MCU i.e. HY12P65
The DTM0660L seems to be good for 6000 counts but people change that setting in EEPROM to get 9999 counts and sometimes it works, other times it's noisy and not so linear.

This multimeter is supposed to be 19,999 counts 4-1/2 digits which I think is the DTM1106EN (even though a teardown pic shows DTM0660L) 

I suspect it's just clever firmware to mask A/D noise and get more counts, this was evident on the AN8008 achieving uV digits this way.

[scorillo47]

Can't wait for Dave Jones' review of this monstrosity. Why does this exist?

[neo2001]

When I use the Bluetooth Audio function, I get a consistent tone/noise. Good thing that I don't use this function. Still it's a little bit disappointing, since I have other Bluetooth speakers which don't make such noises at all.

I still think the basic idea of combining a multimeter, a speaker and a radio clock makes no sense at all - especially battery powered. The device is supposed to be used running off the batteries (according to the manual and the sticker on the back). But who wants to charge a "radio" clock and multimeter every few days or maybe once a week?

I still like it for the multimeter part. Maybe there will be more low cost benchtop multimeters in the future...

[flash2b]

Switch the brightness of the backlight to maximum, and the noise is away. Seems the noise is coming from the PWM, to bad it switches back to backlight medium after power down.

[Andrew_Debbie]

Can't wait for Dave Jones' review of this monstrosity. Why does this exist?

Ignoring the speaker,  this is a darn good bench DMM for $62 plus batteries.   The display is large, bright and easy to read.   The auto ranging is fast.  So is the continuity beeper.   I can't think of anything else that comes close

Inexpensive Bench Autorange DMM list:

AN-888S   19999 Count  $62
VICI VC8145 80,000 Count  $150.
Mastech MS-8040 22000 Count  $175
Uni-T UT803  6,000 Count $200   (May have genuine CAT II rating)

Above prices are direct from China and may be subject to import taxes.

AIM TTi 1604  40,000 Count  600V CAT II   £257  including VAT.   

[Fungus]

Can't wait for Dave Jones' review of this monstrosity. Why does this exist?

Ignoring the speaker,  this is a darn good bench DMM for $62 plus batteries.   

Can it run without batteries?

[Andrew_Debbie]

Can it run without batteries?

Yes, it will run without batteries.  I just checked.   

The manual says to disconnect the charger before measuring high voltages.     




Standard Version without batteries is now  $59.99 on flash sale    This includes free shipping to the UK. Warning of delays due to CNY holiday.

[Andrew_Debbie]

I made a YouTube video showing the AN-888S in operation.   


https://youtu.be/_a4tyW9VWi0

[siggi]

Is the USB port isolated from the test leads? I could see awful things happen if not and the meter is used while charging...

[Andrew_Debbie]

 

I should check.    I don't use the meter when it is charging.

[ResistorRob]

I just spent $34 to get red & black batteries to match the meter, lol

I have 2 questions. (I did read manual first)

1. Will the batteries charge with the power off?
2. Is there anyway to see how much of a charge the battery has while it's charging?

[Andrew_Debbie]

I'll try and find my USB power meter and take some measurements.   That should answer question 1.

I'll run mine down a bit and see what the battery gauge does on charging....

I'll do an unscientific run time test.  I'm using  Sanyo NCR18650GA 3500mAh  because they are red      






 

[NormalZeit]

I've got mine a week ago. Like it very much for the meter part and the large display.

But I'm disappointed about the clock, after one week more than 5 minutes behind time – there I've expected some more precision.

The power consumption in clock mode seems high. With Samsung 18650 25R (2500 mAh) and fully charged it lasts only 3 days before the low battery alarm signal pops in.

[Andrew_Debbie]

After  26 days the clock on mine gained  ~30-40 seconds. 

100ppm crystal  is  8.64 seconds per day.
20ppm crystal is  1.73 seconds per day. 

Mine is  within spec for a 20ppm crystal but that could just be luck.     

I'm doing a battery life check.     After 7 hours of mixed use the battery gauge still has all the segments on.   I'm trying to keep the meter awake.  I even played music for about 30 minutes.  The speaker is awful.   I'm using a 3500mAh Sanyo batteries.



variation =  (f * ppm) / 10^6


https://www.best-microcontroller-projects.com/ppm.html

 

[Andrew_Debbie]

I found a bug in the clock.         Setting the time does not reset the second count.     

[flash2b]

Which clock mode? For me it seems that after the clock is transferred from the circle display to the main display, so when the meter is in standby, the clock is less accurate. But if the meter is kept active, during measurement, the circle clock is accurate.

Also the clock in my meter is accurate when the meter is switched off. After powering up, the time is consistent.

So it seems that clock might run a bit slow only in the standby mode, where the clock digits are presented on the main display.

Did not get a response from neo2001 if his unit is silent, so no noise, after setting the display brightness to maximum while using the speaker function.

[ionospheric]

Hello,

just received AN888S, works nicely.

I noticed when measuring resistance, shorting the probes starts with about 0.15 Ohms, but in a few seconds decrease to 0.001-0.002.
Anyone knows how is this done? It seems no need to use REL to subtract probes resistance when measuring very low resistance.

[Andrew_Debbie]

I have 2 questions. (I did read manual first)

1. Will the batteries charge with the power off?
2. Is there anyway to see how much of a charge the battery has while it's charging?

1 Yes. 
2. I don't think so.    You can hook an in-line usb power monitor and watch the display but that isn't particularly useful.  You can see the charge rate taper off when the cells are close to full. 



The internal  charger draws about 650mA when the DMM is "off".   Turning on the DMM adds another 60mA or so.

[ionospheric]

How is your AN888S when measuring capacitors?
On the nF range mine is OK, 0.7% tolerance for a 10nF.
When measuring 4.7 uF tolerance is about 7% (specs 5%), but for 1000 uF tolerance is 14%!
I have compared with a Hameg HM8118 RLC meter, measuring at 1kHz.

[GrayCat]

Hello!
 
Some info on my ZT-5566 (aka AN888S aka RM123).
 
Here goes its factory EEPROM:

Code: [Select]

Lo- 00─01─02─03─04─05─06─07 ─08─09─0A─0B─0C─0D─0E─0F
Hi.  |  |  |  |  |  |  |  |   |  |  |  |  |  |  |  |
00: FF FF FF FF FF FF FF FF  FF 52 00 FA 00 00 BE 03
10: 10 17 20 4E 52 03 6E 50  64 4B 3C 3C 0A FF 40 FF
20: 10 98 4F 83 64 00 96 00  00 80 00 80 B7 7E D5 8B
30: 4E 02 09 FF 03 09 41 01  0B 28 16 0A 80 01 0A 00
40: 00 01 00 01 00 07 98 00  64 00 64 00 64 00 00 00
50: 00 80 B5 7E D4 8B 00 80  00 80 00 80 00 80 00 80
60: 73 7F 1A 80 0A 00 A8 2A  00 00 00 00 00 00 00 00
70: BF 80 00 80 F2 81 E0 7C  18 01 00 00 00 00 00 00
80: 00 00 00 00 00 16 00 10  00 0C 00 07 17 01 12 03
90: 00 00 00 00 00 00 00 11  00 0D 00 0A 00 02 00 04
A0: 00 00 00 00 00 00 00 00  00 00 00 0B 00 13 00 00
B0: 00 00 00 00 00 00 00 00  00 00 00 00 00 15 00 00
C0: 0D 00 02 10 00 00 00 00  00 00 00 00 20 00 03 10
D0: 0C 80 00 80 00 80 00 80  00 80 03 05 0D 00 02 20
E0: 00 80 00 80 00 80 00 80  00 80 00 80 00 80 00 80
F0: 00 80 FF FF FF FF FF FF  5A 0F 00 00 00 00 00 00
 
The value at 0xF9 is auto-off timeout, in minutes. I set it to 0x3F, now it stays on for 1 hour.
 
If you power-on the unit (button at the back) while depressed "REL" button, it will stay ON forever, but will beep every [ timeout ].

[flash2b]

Does anyone have the Alarm function of the clock working? I mean I can set the alarm time, but it will never beep, tried both meter on and meter off conditions.

[leunamez]

It's a shame to see bad usability decisions on devices that look so good. I confess that I bought this multimeter and it stood forgot on the shelf until last week. Now that I've (finally) cleaned up my lab, I've started to put it to use. But having to take the unit out in order to access the power button, is something that started to get to my nerves. So, one fine day, a new button appeared on the front of the unit!