NEW Brymen Bluetooth BM787BT Multimeter

[EEVblog]

Cats out of the bag, Joe Smith just released an unboxing video, mine is still on the Fedex plane.
Brymen are releasing a new BM787BT/788BT bluetooth version of the BM780 series.
My exclusive one will be called the BM787BT. It's not the BM786BT because it will also have the LowZ mode that the BM786 didn't.

This is the Bluetooth variant Brymen promised when they released the BM780 originally 5 years ago.
The BM780 series back then even had the Bluetooth module pin header and a BT marker on the PCB, but I guess it took them this long to get it right.
There will initially be an android app available.

[bdunham7]

My exclusive one will be called the BM787BT. It's not the BM786BT because it will also have the LowZ mode that the BM786 didn't.

OK, that's a plus. 1000V LowZ adds a few bucks.

[EEVblog]

OK, that's a plus. 1000V LowZ adds a few bucks.

Yes, the price increased a bit for that.

[joeqsmith]

....
There will initially be an android app available.

The UNI-T UT181A also only supported Andoid with their BLE interface.  When writing the software for that meter, I had borrowed an old Android and bought one of those Adafruit sniffers for Wireshark to reverse engineer the protocol.  This was before meeting with others who had also reverse engineered the interface.   

I still do not own a cell phone.   Having a known working setup where I could sniff the traffic would certainly help answer some of my questions, but Brymen continues to be very responsive.  With the time difference between our countries, it will take some time to sort it out. 

I am not aware of them planning to support any other platforms.  My hope is that by working with them, they will create and release an interface specification into the public domain.   This would allow the creators of some of the other applications to add support for this meter. 

[mwb1100]

My hope is that by working with them, they will create and release an interface specification into the public domain.

The have published the specs for their "wired" data logging meters, so I'd expect (hope?) they'd do the same for this bluetooth protocol.

[BILLPOD]

I still do not own a cell phone.   

Good Morning Joe,   I thought I was the only one on earth that doesn't own a cell phone.
Good to know I'm not alone.

[EEVblog]

I am not aware of them planning to support any other platforms.  My hope is that by working with them, they will create and release an interface specification into the public domain.   This would allow the creators of some of the other applications to add support for this meter.

They originally said it would be an open protocol, and they have sent it to me, but just the other day they asked me to hold off releasing it while they re-evaluate that. I can't think of any reason not to release it, people will just reverse engineer it anyway.
The mentioned Androd, iOS and Windows apps, but only Android is available right now. I have that installed but can't do anything until my meter arrives.
Was supposed to get it yesterday but Fedex are behind schedule, so it's saying Monday now.

[joeqsmith]

They had asked me about the pros and cons of making it public domain.   I made a case for releasing it. 

I told them my only concern with making it public would be if a end user could brick the meter using that interface.  Overwrite the calibration for example.   A better example would be if you change the password and loose it.  You can't query the password unless you send the password.  They plan to have a comment in the manual on how to reset the meter back to the factory settings (which includes the password).   

I have yet to get the meter to send data and am asking them for further clarifications.  IMO, it would be a bit premature to release that document.  Are you planning to write your own custom software for it?

[EEVblog]

Fedex tracking now says it's on the truck for today.
Should I do a live stream doing a teardown and phone connection test?

[EEVblog]

Are you planning to write your own custom software for it?

No plans if they are going to ahead with the apps for all platforms, and the protocol is released.

[EEVblog]

I told them my only concern with making it public would be if a end user could brick the meter using that interface.  Overwrite the calibration for example.   A better example would be if you change the password and loose it.  You can't query the password unless you send the password.  They plan to have a comment in the manual on how to reset the meter back to the factory settings (which includes the password).   

I don't know why that password exists, maybe they have a customer application in mind.
There is no mention in the protocol of being able to send calibration data, so seems impossible to goof up the meter.

[joeqsmith]

I told them my only concern with making it public would be if a end user could brick the meter using that interface.  Overwrite the calibration for example.   A better example would be if you change the password and loose it.  You can't query the password unless you send the password.  They plan to have a comment in the manual on how to reset the meter back to the factory settings (which includes the password).   

I don't know why that password exists, maybe they have a customer application in mind.
There is no mention in the protocol of being able to send calibration data, so seems impossible to goof up the meter.

Note that the specification I have states "to be continued".   It's obviously a preliminary spec.  Working with the BLE interface, the meter reports undocumented handles.  These UUIDs are similar to the ones mentioned in the specification.   

[EEVblog]

I have to leave in 10min and no sign of the Fedex truck. Guaranteed not to turn up this week now. No ability to mark as leave without signature.

[EEVblog]

Fedex guy left it! 

[u666sa]

Bleh. I have a UNI-T UT61E+ here. It is also Bluetooth capable. However, that is a stretch to say it like that. When I ordered Bluetooth dongle I found out that there is no software for windows, there is software only for iPhone. Since I wanted to display multimeter information in OBS, it's as good as it don't have any Bluetooth. 

Unless of course me want to write my own software for Windows.

[tautech]

Bleh. I have a UNI-T UT61E+ here. It is also Bluetooth capable. However, that is a stretch to say it like that. When I ordered Bluetooth dongle I found out that there is no software for windows, there is software only for iPhone. Since I wanted to display multimeter information in OBS, it's as good as it don't have any Bluetooth. 

Unless of course me want to write my own software for Windows.

Yet both of the mini PC's here, running Windoze 10&11 are Bluetooth capable.
Some new toys demand new PC HW......

[joeqsmith]

Bleh. I have a UNI-T UT61E+ here. It is also Bluetooth capable. However, that is a stretch to say it like that. When I ordered Bluetooth dongle I found out that there is no software for windows, there is software only for iPhone. Since I wanted to display multimeter information in OBS, it's as good as it don't have any Bluetooth. 

Unless of course me want to write my own software for Windows.

Yet both of the mini PC's here, running Windoze 10&11 are Bluetooth capable.
Some new toys demand new PC HW......

While Windows has supported BLE for years, this does not suggest UNI-T wrote software for that platform.   

I ran into the same problem with the BLE adapter for their UT-181A.  They advertised having software for Windows but when the adapter arrived, they had nothing.  The only way to get it running was to write my own Windows application.   This is NOT a HW problem as suggested.  It's a lack of software.

Fedex guy left it! 

When/where is the live stream? 

You should have an updated manual today.   This answered some of my questions but I am still unable to get the meter to respond correctly.   

[u666sa]

are Bluetooth capable

That's not my point, but niet. Both of your PCs are not proper bluetooth capable. You need a special adapter in most cases, with programmer (or you stuck with manufacturer's adapter). But buying an adapter with programmer is cheaper and more flexible solution!!

It's called Zigbee CC2540 (not CC2531). After it arrives, you flash it with correct firmware and your multimeter will connect properly to windows. Essentially adapters that manufacturers sell is this thing, programmed, and wrapped in plastics.

https://ibb.co/wFg4ch0b

write my own Windows application

Is it availble for public download? Could you provide link to your software? Perhaps source code?

[u666sa]

I have some time to kill at this point and can program. I might as well write an app in FireMonkey for Windows, Linux and Mac.

[mwb1100]

One very minor note on a difference between Dave's BM787BT and Joe's BM788BT:

  - Dave's BM787BT case is from a BM789 with tape obscuring missing functions or adding the  missing bits and nameplate
  - Joe's BM788BT case is unmodified - it's very much like a BM789's case, but there's no tape obscuring the dBm mode marking or tape used for the meter's nameplate

Like I said - a minor thing.  Brymen is farther along with the BM788BT (as one would expect) or maybe they had some BM788BT cases lying around from the abandoned/stalled effort 5 years ago.

It looks like the BM787BT is a BM786 with bluetooth and nothing else added.  The BM788BT is BM789 with bluetooth added and dBm support removed (maybe also without the 100kHz bandwidth?)

[danno_cj]

BM787BT got LoZ, this feature is missing on BM786.

[bdunham7]

It looks like the BM787BT is a BM786 with bluetooth and nothing else added.  The BM788BT is BM789 with bluetooth added and dBm support removed (maybe also without the 100kHz bandwidth?)

I think there's too much market micro-segmentation here--there's now 5 different meters (785, 786, 787BT, 788BT, 789) based on one common design and with one feature added or deleted here and there.  Does it really change the cost to add or delete the dBm or 4-20mA loop features?  Perhaps there is a good reason for some of this, namely allowing for an EEVBlog version without violating current agreements with other distributors.  But why have a 788BT with just a few minor features deleted from the 789?  Anyway, the 787BT looks like it has a good set of core features now that they've added LowZ.  I hope the price is competitive. 

BT is very handy for household electrical work because it allows you to put the meter one place while you go operate something elsewhere and get a reading on your phone.  I'm not as enthusiastic about using this as a logging method, but we'll see how that shakes out.  Let's see if Dave and Joe can actually get their respective samples working correctly...

[joeqsmith]

I would have thought having a different colored boot with a different part number and selling the 789 would have been cheaper than the engineering and documentation to have this different models.

... Does it really change the cost to add or delete the dBm or 4-20mA loop features? 

I had asked why they dropped support for dBm with the BM788BT.  Apparently they ran out of code space when adding the BLE option. 

.. I'm not as enthusiastic about using this as a logging method, but we'll see how that shakes out.  Let's see if Dave and Joe can actually get their respective samples working correctly...

Brymen have been working at answering my questions about the BLE interface.   As I mentioned, they provided an update to the standard today.  If Dave stays with the provided software, I expect it will just work.   I'm a ways off from being able to do any sort of testing with it.

[mwb1100]

Perhaps there is a good reason for some of this, namely allowing for an EEVBlog version without violating current agreements with other distributors.

My recollection is that this was exactly why the 786.  Don't know why that wasn't needed for the BM235.

[EEVblog]

Bleh. I have a UNI-T UT61E+ here. It is also Bluetooth capable. However, that is a stretch to say it like that. When I ordered Bluetooth dongle I found out that there is no software for windows, there is software only for iPhone. Since I wanted to display multimeter information in OBS, it's as good as it don't have any Bluetooth. 
Unless of course me want to write my own software for Windows.

It's all about the software. Bryemn just said that Android and iOS will be available upon release, with Windows a few months later.
I'd show you a screen shot, but I just get the message "Pairing rejected by BM78xBT"