USB Power Monitor

[classical]

Hi,
Thanks for the USB power monitor review.
I user several of it an can confirm that the serial resitance is a crucial point. Some devices like chargers, qi charging coils etc. run with reduced performance at bigger voltage drop over the shunt.
There exists some units with 50mOhm or even 25mOhm and some of them (incl portaPow) are well described here:
http://www.lygte-info.dk/info/indexUSB%20UK.html

[iloveelectronics]

Hi,
Thanks for the USB power monitor review.
I user several of it an can confirm that the serial resitance is a crucial point. Some devices like chargers, qi charging coils etc. run with reduced performance at bigger voltage drop over the shunt.
There exists some units with 50mOhm or even 25mOhm and some of them (incl portaPow) are well described here:
http://www.lygte-info.dk/info/indexUSB%20UK.html

Great reviews there on that link! And I just wanted to add that according to the official documentation of the YZXstudio device I sent, the shunt resistance is 10mOhm and the overall circuit's resistive loss is about 40mOhm.

[birrbert]

Thanks for the video. Awesome device! Far more versatile than the ones I saw until now. This is something I could really use with my small solar power projects. Martin, is there any chance for a quick take a look inside? If not a video then maybe some photos here on the forum? I see that it's held together by screws so opening shouldn't be a problem.

[classical]

And I just wanted to add that according to the official documentation of the YZXstudio device I sent, the shunt resistance is 10mOhm and the overall circuit's resistive loss is about 40mOhm.

Sounds very promising!
Looking at Martins video 18:02 I would calculate 100mOhm including his connectors and cables.
What does the "fast charge mode" do?
There are different requirements for different devices as you can see in http://lygte-info.dk/info/usbPowerSupplyTestHow%20UK.html at the end of the side under "USB Coding". Most apple products need special voltage levels at the data lines, most androids wants the data lines to be shortened, some to be opened.
Some modern chargers uses "intelligent" chips of TI or maxim which try to find out what the connected device wants to see.
I also have the impression that some chargers deliver more than 5V to compensate these resitances. At  the other hand this increases the risk of overvoltage at the end of the charging process.

[SeanB]

I have some of Frankies cheaper ( $5 IIRC) USB monitors, and they work well, though not as good as these do. With the OLED display I have one in a Transcend media player, and I will agree it is a beautiful display.

You probably will see a single microcontroller, and not much more than that inside, aside from a sense resistor for current ( most likely on the ground lead) and a few voltage divider resistors, and then a LDO and a single transistor for the display control, with a few capacitors and likely a crystal for the microcontroller.

Would be nice for V3 to have a USB hub inside with the output port on one section and the microcontroller on the other, delivering the data so that you can have a PC read and work with the info.

[iloveelectronics]

And I just wanted to add that according to the official documentation of the YZXstudio device I sent, the shunt resistance is 10mOhm and the overall circuit's resistive loss is about 40mOhm.

Sounds very promising!
Looking at Martins video 18:02 I would calculate 100mOhm including his connectors and cables.
What does the "fast charge mode" do?
There are different requirements for different devices as you can see in http://lygte-info.dk/info/usbPowerSupplyTestHow%20UK.html at the end of the side under "USB Coding". Most apple products need special voltage levels at the data lines, most androids wants the data lines to be shortened, some to be opened.
Some modern chargers uses "intelligent" chips of TI or maxim which try to find out what the connected device wants to see.
I also have the impression that some chargers deliver more than 5V to compensate these resitances. At  the other hand this increases the risk of overvoltage at the end of the charging process.

I haven't tested that myself but according to the maker of the device the "fast charge mode" is used to emulate these different "signals" used by proprietary devices (automatically detected) so that you can charge them at the fastest rate using third-party chargers. You will still be limited by the charging ability of your chargers though of course.

[classical]

according to the maker of the device the "fast charge mode" is used to emulate these different "signals" used by proprietary devices (automatically detected) so that you can charge them at the fastest rate using third-party chargers.

Maybe they use a TPS2511 http://www.ti.com/lit/ds/symlink/tps2511.pdf or a maxim 14578 http://datasheets.maximintegrated.com/en/ds/MAX14578AE-MAX14578E.pdf . In the data sheets the different modes are listed.
Does the USB Power Monitor tell which mode was used to achive the "fast charging" in a specific case? So it could be used as a kind of analyzer, too.

[iloveelectronics]

Just thought I would upload a close up view of the latest hardware version of the device, underneath the OLED display. The chip on the left is a FM24CL04BG FRAM and the one on the right is a STM32F030F4P6.

[rgumpertz]

While searching for the ZYXstudio USB 3.0 Power Monitor on the web, I discovered that there are several different colors available (at least yellow, red, and blue).  There was also some hint that the color changes denote newer models.  What is the latest revision?

Also, is there a web site or e-mail address for the developer?

[iloveelectronics]

This video should demonstrate better the differences between the current 2 versions (Red and Yellow Mini): https://www.youtube.com/watch?v=IVNA4gvQzKo

[Haldi]

Hi,
I've seen the Review and it was great. Answered a lot of my questions other youtube reviewers didn't even ask.


I've read on Ebay that there is a new firmware for this device,

2015-06-25 - New major firmware upgrade (v2.5) available. Units sold from this day onwards will be loaded with this latest firmware. Please see description below for the new features and improvements in this upgrade. Previous customers interested in the upgrade can contact me for the firmware file and upgrade procedure (will require a ST-Link V2 compatible programmer).

especially nr6 captured my interest:

6. Allows remote data logging by connecting a UART USB/Serial adapter, or a Bluetooth or Wifi module (neither of these is included with this item, user needs to provide their own) to the solder pads normally used for firmware update. Users will need to use their own serial communication software for the actual logging and data analysis though. The USB Power Monitor simply sends the raw data.

Yet there are a few question i cannot answer myself.
1: Where do you connect these things ? "solder pads" kinda hard to see on all pictures you can find on the internet.
2: "UART USB adapter" ? wouldn't that be the "ST-Link V2 Compatible STM8 STM32" used for firmware updates?
3: Software for Serial Communication? Recommendation for simply capturing all data and write is as a .csv file ?
4: If you would use Bluetooth or Wireless that would get hella lot more complicated right ?

Maybe anyone here can help me answer this question.


P.S
Who is the Manufacturer of this device? YZX Studios? Couldn't really find much infos about that on the web. Do they have a website?

[iloveelectronics]

1: Where do you connect these things ? "solder pads" kinda hard to see on all pictures you can find on the internet.
2: "UART USB adapter" ? wouldn't that be the "ST-Link V2 Compatible STM8 STM32" used for firmware updates?
3: Software for Serial Communication? Recommendation for simply capturing all data and write is as a .csv file ?
4: If you would use Bluetooth or Wireless that would get hella lot more complicated right ?

1. This picture with the USB Power Monitor connected to a bluetooth module should answer you question nicely (click to enlarge):


2. The firmware upgrade and the UART interface actually share the same contact points, which means when you perform a firmware upgrade you will need to temporarily desolder any serial communication links.

3. Any serial terminal or bluetooth terminal applications will do the job. The device doesn't come with any software so you will have to use an off-the-shelf software/app and record the data. Usually these software/apps would allow .csv saving. In the following picture I'm remotely logging the data via bluetooth. You can see the data format there (6-digit voltage and current readings):


4. As you can see in the pictures it really isn't that complicated at all. Connect the module, enable the data logging in the bootup settings, pair up the device with the software/app and you're good to go!

P.S
Who is the Manufacturer of this device? YZX Studios? Couldn't really find much infos about that on the web. Do they have a website?

They don't really have a website except a shop in the Chinese TaoBao marketplace: http://yzxstudio.world.taobao.com

[Haldi]

Hi, thanks for this answer.
Looking forward to play around with this thingy.

[M. AlGailani]

As a response to USB Power Monitor Review - Pt2 video, I made some measurements on PortaPow Premium unit.
I used the followings:
1.  New PortaPow unit
2. Fluke 289, Fluke 115 (both purchased last year)
3. Dave Jones uCurrent Gold (6 months old)
4. BK Precision 1671A power supply (18 months old)

I used 14 different values from the power supply to measure the voltage and current accuracy. My interest lies in the 0-5 volts/ 0-4.5 amps range only, as I use the PortaPow to measure the supplied voltages and currents to some of my Microcontroller/FPGA projects.

Delta is the difference between the PortaPow and Fluke readings (current/voltage).

[SteveyG]

1: Where do you connect these things ? "solder pads" kinda hard to see on all pictures you can find on the internet.
2: "UART USB adapter" ? wouldn't that be the "ST-Link V2 Compatible STM8 STM32" used for firmware updates?
3: Software for Serial Communication? Recommendation for simply capturing all data and write is as a .csv file ?
4: If you would use Bluetooth or Wireless that would get hella lot more complicated right ?

1. This picture with the USB Power Monitor connected to a bluetooth module should answer you question nicely (click to enlarge):


2. The firmware upgrade and the UART interface actually share the same contact points, which means when you perform a firmware upgrade you will need to temporarily desolder any serial communication links.

3. Any serial terminal or bluetooth terminal applications will do the job. The device doesn't come with any software so you will have to use an off-the-shelf software/app and record the data. Usually these software/apps would allow .csv saving. In the following picture I'm remotely logging the data via bluetooth. You can see the data format there (6-digit voltage and current readings):


4. As you can see in the pictures it really isn't that complicated at all. Connect the module, enable the data logging in the bootup settings, pair up the device with the software/app and you're good to go!

P.S
Who is the Manufacturer of this device? YZX Studios? Couldn't really find much infos about that on the web. Do they have a website?

They don't really have a website except a shop in the Chinese TaoBao marketplace: http://yzxstudio.world.taobao.com

This looks quite interesting - I may have to pick one of these up to play around with. Presumably once enabled it just keeps firing data out of the UART?