Uni-t ut-d07a Bluetooth..

[joeqsmith]

I was working on my software for the UT181A and noticed a strange behavior with the meter.   I was feeding it with a 800uV pk sine and noticed that the meter seem to have a disturbance at 300uV with the slow hi-res ADC.   It seems repeatable but what is really strange is if I plot the fast low-res ADC, I see a very strange wave shape and it just happens to line up with the fast ADCs disturbance.  I suspect its a problem with that chipset they use.   

[Brannigan]

So, I replicated your test conditions and got pretty much the same thing, only worse.

I was using a ~ .07 Hz sine and found "The jump" occurred at around + 300 uV on the leading edge and + 100 uV on the trailing edge.

About 50 % of the time I would get a big jump (~100 uv and then it would fall back , in other words, go in the wrong direction.
I used the Uni-T utility just to make sure I wasn't seeing any bugs in my ongoing software development.
 
It strongly looks like some sort of hysteresis, but it's tough to tell if it's software or hardware. The anomaly doesn't occur at zero, nor is it symmetrical about zero, so if I had to guess, it's something to do with the digital calibration removing the DC offset, fighting with some hysteresis in the in the front end, but that's just a SWAG. Because it doesn't happen all the time, it seems to be timing interaction between when the input crosses zero and the meter takes a sample/reading, likely a settling time issue. It doesn't seem to get "stuck". which would be a real problem.

When measuring a similar DC voltage, it is tough to tell how fast it responds to slight changes. At 800 uV, you're kinda in the weeds and I don't have a fully shielded set-up for this quick test. That said, it does appear to stabilize fairly quickly. When I have time, I will test for monotonicity or missing codes. For now I'm a little disappointed, but I think it's just something to be aware of.   

[joeqsmith]

Thanks for checking.  At least I know it's not unique to this meter.

[spiff72]

Based on the work you guys have done with this adapter - do you see any reason that it wouldn't work with a Triplett 9065 meter?  This appears to be a rebadge of the UT181A. 

(In other words, would you expect that slightly different firmware would have any effect on it?  My intent is to use it with the Android app.)

[mjab]

Hello, was it possible to develop a ready-made program for Windows? Today I bought a UT-D07A module and I have the same problem as everyone else.

[ladnene]

Can you please share your labview software for UNI-T UT181A ? i need a quick datalogging multimeter to detect transient/fast signals ( between 10-100ms), in the datasheet it is written that the UT181A had a 10hz refresh rate which i hoped would be enought and it was the reason i bought this multimeter, but later when i plugged it with the PC i discovered it did send 10 mesures/s but it sends a new value only for each 2 values, so it had only 5hz in reality like i discovered in your videos ... hopefully the analog bargraph is fast enought to detect the signal but i can't find anyway else then your program to log it's data. Your software will help me read the bargraph values and spare some money which i really need lately. i have been looking for a link for your software for days now and no luck ... can you please help ?

[ladnene]

Anyway, i am starting my own custom software for UT181A multimeter, this is beta version : https://github.com/ladnene/UT181A_TOOL. i learned to code with python in the last 2 days and implemented these features so don't judge if you get any error  , will be implementing new features more and more like data reception over bluetooth and real time graphing. just sharing this with you in case someone needs it.

[pami3r]

Hi anybody can resolve the ut-d07 conection to windows? thanks

[pami3r]

Hi can you share your ut181a program?