New EEVblog BM786 Multimeter

[joeqsmith]

Firmware updates for BM786.
And Brymen have confirmed that recalibration after firmware update is not required.

When I first looked at the 786/9, I was told that swapping the IC could require the meter to need realignment.  While working on the review of the 769, this came up again and they provided a little more detail, suggesting that it only effects the 789.   

I wonder if reprogramming the firmware for the 789 vs swapping the IC would still require realignment.   Shipping takes a fair bit of time.    I'm still waiting on the new 789 to arrive so we can move ahead with the review. 

[EEVblog]

Thanks for the heads-up on this DMM! It looks great and it is available thru Amazon here in the US now which is great!!

Just shipped 80 more units to Amazon US. Both meters sell very well on Amazon.

[EEVblog]

Firmware updates for BM786.
And Brymen have confirmed that recalibration after firmware update is not required.

When I first looked at the 786/9, I was told that swapping the IC could require the meter to need realignment.  While working on the review of the 769, this came up again and they provided a little more detail, suggesting that it only effects the 789.

You'd expect swapping the IC on all models to potentially require realignment. As the micro likely has internal ADCs for auxillary measurements that will have individual calibration factors.
EDIT: I can confirm that the micro contains a 21bit sigma-delta ADC, and I presume this is the main measurement ADC.
So yes, certainly you can't just change the micro and expect zero measurement difference.

[EEVblog]

Firmware updating works:

[firewalker]

Did anyone started hacking it?

Alexander.

[EEVblog]

LOL at all the salty people in the comments 

[firewalker]

Why your variant of BM786 has a flash and not an otp device? Was something you asked for?

Alexander.

[EEVblog]

Why your variant of BM786 has a flash and not an otp device? Was something you asked for?

Nope, wasn't my request. All the 780 series has it.
EDIT: I'm assuming all the 780 series has it. I have never seen the other meters in the series, but it would be crazy if they didn't, as they clearly went to all the effort to include the external header in the original 780 design case.

[joeqsmith]

According to Brymen, the BM786 doesn't need to re-calibrated after MCU replacement.   I have not made any attempt to reverse engineer any part of the two meters but according to Brymen, the they use" different designs on this part".

I thought you had posted a picture a few days ago about a new programmer but I can't seem to find it now.  I was guessing that was the programmer for these meters.  Then again, just waking up so maybe I dreampt the whole thing. 

[EEVblog]

I thought you had posted a picture a few days ago about a new programmer but I can't seem to find it now.  I was guessing that was the programmer for these meters.  Then again, just waking up so maybe I dreampt the whole thing.

I have never posted a photo or any details of the programmer. I had to sign an NDA to specifically get the programmer.

[Cymaphore]

Nope, wasn't my request. All the 780 series has it.
EDIT: I'm assuming all the 780 series has it. I have never seen the other meters in the series, but it would be crazy if they didn't, as they clearly went to all the effort to include the external header in the original 780 design case.

My personal assumption is, that the BM78x even share the same PCB, since my BM789 contains model markers near the input jacks indicating variants BM783, BM784, BM785, BM786, BM787, BM788, BM789 (with solder dot in mine) and also the "BT" (Bluetooth (LE) variant). Data port for BT is present under the display but unused in the standard BM789.

So it seems unlikely they differ more than absolutely nessasary.

Closeup in my BM789 (see the markings left and right of the jacks):



My BM789 also has the same kind of pinhead as the BM786 (top right):

[joeqsmith]

I thought you had posted a picture a few days ago about a new programmer but I can't seem to find it now.  I was guessing that was the programmer for these meters.  Then again, just waking up so maybe I dreampt the whole thing.

I have never posted a photo or any details of the programmer. I had to sign an NDA to specifically get the programmer.

Went through my history and found what I mentioned and it wasn't even your post.  You had posted just prior.  Funny who how (case and point)  the brain works, or misfires... 
 
https://www.eevblog.com/forum/chat/what-did-you-buy-today-post-your-latest-purchase!/msg3610195/#msg3610195

[joeqsmith]

My personal assumption is, that the BM78x even share the same PCB, ....

They do. 

[EEVblog]

Nope, wasn't my request. All the 780 series has it.
EDIT: I'm assuming all the 780 series has it. I have never seen the other meters in the series, but it would be crazy if they didn't, as they clearly went to all the effort to include the external header in the original 780 design case.

My personal assumption is, that the BM78x even share the same PCB, since my BM789 contains model markers near the input jacks indicating variants BM783, BM784, BM785, BM786, BM787, BM788, BM789 (with solder dot in mine) and also the "BT" (Bluetooth (LE) variant). Data port for BT is present under the display but unused in the standard BM789.
So it seems unlikely they differ more than absolutely nessasary.

Yes, this common among all Brymen lines, the 780 would be no different.

[EEVblog]

I thought you had posted a picture a few days ago about a new programmer but I can't seem to find it now.  I was guessing that was the programmer for these meters.  Then again, just waking up so maybe I dreampt the whole thing.

I have never posted a photo or any details of the programmer. I had to sign an NDA to specifically get the programmer.

Went through my history and found what I mentioned and it wasn't even your post.  You had posted just prior.  Funny who how (case and point)  the brain works, or misfires... 
https://www.eevblog.com/forum/chat/what-did-you-buy-today-post-your-latest-purchase!/msg3610195/#msg3610195

The brains visual compression algorithm at work!

[joeqsmith]

Did you set a new personal best for up vs down votes?      

[EEVblog]

Did you set a new personal best for up vs down votes?   

18% thumbs down. Bad, but not a record.
I think either the pouring beer down the drain video, or the video where I made a dead cat joke are still the winners.
I lost 1000+ subs because of the dead cat joke.

[Fungus]

I lost 1000+ subs because of the dead cat joke.

Was it a "joke" or a "remark"? 

[EEVblog]

I lost 1000+ subs because of the dead cat joke.

Was it a "joke" or a "remark"? 

Was something along the lines of "the only good cat is a dead cat" 

[joeqsmith]

The video where I first ran the UNI-T UT139C,  87 down, 64 up.   Meter shows up late to the party and dies in the first few hits.  The initial shock of seeing how poorly it performed and apparently I didn't show it the proper respect it deserved,  upset the fan base.     

By the time I purchased a second one to repeat the test, even though the meter failed at the same level with the same test, the fans must have knew what was coming.  11 down, 236 up.   

[gnavigator1007]

Was something along the lines of "the only good cat is a dead cat" 

Hehehe I remember that one because my wife walked into the room just in time to hear it.

[oPossum]

[EEVblog]

The video where I first ran the UNI-T UT139C,  87 down, 64 up.   Meter shows up late to the party and dies in the first few hits.  The initial shock of seeing how poorly it performed and apparently I didn't show it the proper respect it deserved,  upset the fan base.     

535 down 388 up is my best/worst ratio I think with the beer down the sink video.

[tautech]

I lost 1000+ subs because of the dead cat joke.

Was it a "joke" or a "remark"? 

Was something along the lines of "the only good cat is a dead cat" 

You'd be sent on your way coming out with that on NZ high country stations because as we don't have Dingos but only wild cats and ferrets predate on the high seasonal wild rabbit population.
Luckily we now have the RCD virus smuggled in from Oz that better helps keep them in check.

[robert.rozee]

[...] we don't have Dingos but only wild cats and ferrets [to] predate on the high seasonal wild rabbit population.
Luckily we now have the RCD virus smuggled in from Oz that better helps keep them in check.

last i heard, RCD was failing abysmally down south, with the rabbit population developing immunity. but the dingo idea has come merits - perhaps our farmers should try importing a few thousand dingos and see how they do at controlling the rabbit population.


cheers,
rob   :-)