开云体育

Richard,

maybe these instructions might help you?
Absolute Beginner's Guide to The NanoVNA ,
Chapter "NanoVNA FIRMWARE UPGRADE".

It is in the files section of this group.

73
Martin 9A2JK

Hi Richard,
Okay, I see you've gotten to the point where you have a white screen (if all is true, it's because your device is in DFU mode).
Please turn it on if the screen is still white and I assume that because the display is not damaged, the device is in DFU mode.
In the earlier versions, the white state on the 2.8 "screens indicates the DFU mode.
This changes in later versions so that you can switch from the menu to the DFU state.

Important: the device cannot be used in DFU mode only firmware upload or download!
When connected to a computer in DFU mode, you should see "STM Device in DFU mode" in the USB controllers in Device Manager.
If you see this, your computer will see the device.
You can only change this if you upload the .dfu file correctly, which is a prerequisite for the tool to work.
If you make a mistake here and there is no hardware error, DFU mode will remain and the device cannot be used to measure.

If it is not visible, you need to short-circuit BOOT0 and VDD in the corner next to the battery on the device's motherboard when the power is off.
You insert a small wire into the hole galvanized hole, then turn on the device. Your device is now in DFU mode. Nano VNA_ (hw-3.4) .jpg
You can only change this if you upload the .dfu file correctly, which is a prerequisite for the tool to work.
If you make a mistake here and there is no hardware error, DFU mode will remain and the device cannot be used.

I attach an image The "Choose ..." and "Upgrade" buttons at the bottom right of the DfuSe Demo program must be used to upload.
(the one on the left is used to read the .dfu in the device). DfuSe_Demo_upgrade.png
Before I wrote this message, I also uploaded Hugen's 1.0.45 firmware to my 2.8 "device.
In this version, the captions are larger than the ones made by the original author DiSlord - I think it will be more readable for you.
Hugen_v1.0.45_screenshot.png

Once the firmware upload is successful, the power must be disconnected and remove BOOT0-VDD short-circuit, then turned on.
You must then log in correctly.

73, Gyula HA3HZ
--
*** If you are not part of the solution, then you are the problem. ( ) ***

Thank you so much for this tutorial! It is so good!!!

Terry NQ4Y

Ditto. Would love to hear the presentation accompanying the slides.

Jim
KQ9I

Very good Barry! Please let us know when you finally decide to release a YouTube recording of you narrating your slide presentation. I will be first in line to watch it!

Regards,
Gregg

--
VE6WGM

One of the pitfalls of making component measurements is using the wrong impedance measurement technique.

In this post I am using a NanoVNA-H4 and measuring a 1K and a 3K resistor to see how accurate the resistance can be calculated by connecting it to CH0 with a SMA test jig (shown in previous posts) and doing a S11 measurement. The NanoVNA hardware measures the reflection coefficient Gamma (Γ) and firmware on the device calculates impedance by the following equation Z = Zo * ((1 + Γ) / (1 - Γ)). Zo is 50 ohms and Z and Γ are complex numbers. Z calculated using this method is in the form R +/- jX which is known as a "serial impedance" representation and can be plotted on the NanoVNA device by selecting the appropriate traces. A plot of the 1K SMD 1206 resistor using this standard method is shown below. Actual DC resistance on a DE-5000 LCR meter was 997 ohms. Note how the calculated value is very close to 997 ohms at 10 kilohertz but quickly drops to 950 ohms at 250 MHz. At first glance it seems that the NanoVNA cannot do a good job of measuring this component at higher frequencies and some users might put this down to being so far away from the 50 ohm system impedance of the NanoVNA hardware.

However a real world resistor is not a pure resistance but has inductance in the leads and a stray capacitance in parallel with the resistance. This is shown in the simplified model below. In the case of a small SMD resistor this lead inductance is very small and the capacitance across the resistor is the dominate reactance. The first plot was a "series impedance" measurement of the 997 resistor which is a standard way of plotting impedance but it does not represent the actual physical component. An alternate form is the "parallel impedance" which is R // +/-jX and unfortunately is not available for plotting on the NanoVNA itself. Some PC packages like NanoVNASharp MODv3 and NanoVNA app by OneOfEleven do have this calculation capability and it is very useful. The parallel impedance plot below takes into account the parallel capacitance across the resistor and we can see the resistance is fairly consistent across the frequency range and deviates by a maximum of 10 ohms from the 997 ohms at DC. The next plot shows the capacitive reactance and if we calculate it by C= 1(2*pi*freq*X) it varies from 0.14 to 0.15 pF which is a very small.

The last test measured a SMD 1206 3K resistor on the same SMA test jig. This part has a DC resistance of 3003 ohms. Serial and parallel impedance plots are below. In a similar fashion the serial impedance method results in a poor estimate across the frequency range but the parallel method is much better and is off by up to 100 ohms maximum or 3.5% which is fairly reasonable.

I hope this post provides some insight into the measurement capability of the NanoVNA-H4 at higher impedances.

Roger

Richard, verify you can access the unit via the console through a terminal app like putty or teraterm. If you can access that way, you have a display issue.?
Some forum members, including myself, have had to resolver the display ribbon to the PCB.?


On Wed., 24 Feb. 2021 at 3:56 p.m., VE2DX<ve2dx@...> wrote: OK, was finaly able to get the NanoVNA-H in DFU mode and was able to find it in DfuSeDemo...

loaded the proper firmware DFU file and loaded it correctly as per the procedure...

the unit is still dead!...

While in DFU mode the Blue LED stopped flashing and did comeup in win10 as STM32 Bootloader like it should be...

the DfuSeDemo found the unit, I was able to load the proper firmware even did a VERIFY and confirmed it was loaded.

removed the jumper

rebooted the NanoVNA-H, blue led started flashing again and... wait for it... NOTHING

Just a white screen!

looks to me like the unit is not having firmware issues...? instead I think this is a HARDWARE display issue???

comments or suggestions please

73

Richard VE2DX

Unsolved the battery and see if it runs when connected by USB. Sometimes, a dead liion battery will prevent the inverter from starting up.?


On Wed., 24 Feb. 2021 at 4:47 p.m., Charlie N2MHS via groups.io<ucfargis1@...> wrote: Not to be offensive but have verified 3 volt and 5 volt power? LEDs lit>

/almost/ all of it.....



Enjoy!

--
jim fisher
Jedijf
AJ3DI
www.aj3di.com
HamshackHotline ext: 14423
"Do, or do not. There is no 'try.'"
-- Jedi Master Yoda

Thanks, Barry, you did a good job on this. I was only wishing you had narrated or provided slides with your explanations as well, though.
I agree with Jim Lux, your PowerPoint should be on YouTube, so others can learn from you.

73
W7BPG

On 2/23/21 5:38 PM, Michael wrote:

Now let's go off the deep end -

how do you characterize ferrites and powder iron (rod and toroid) for useable frequency as inductors/choke, transformers, and wide band transformers?

Mike
N9XYP

a) You wind a few turns on a core and measure the R and X, then back that out to u' and u'' vs frequency.

b) Or you use the manufacturer's data sheets with the same information.

One could probably come up with a procedure to use a NanoVNA and a few turns to "identify" core materials, by matching measurements (a) with data sheets (b).


The real value is when you actually build that choke, transformer, or other widget. The NanoVNA helps you figure out if your performance matches the expectations, because there's always parasitic C issues, R loss, etc.

Thank you all for the great suggestions. I will modify (correct) the TDR slides. I was fascinated to watch the TDR "work" so well with some old coax I had in my shack, and just googled TDR to see if I could understand HOW it works.

Now.. I am at about a 9th grade understanding of this VNA technology, and I should know, since I taught 9th grade Physics for ten years at the end of teaching high school physics for 41 years (then university levels).

I've looked at the Nano VNA as something that I wanted to "tame" and have had fun learning, reading, playing, and even giving a few talks PPT to local clubs and some not so local to Philadelphia. With each presentation, I learn something new from the questions that pop up.

So no, I am not keen to "record" a presentation, although most of the clubs do record an hour or more for their own membership.

So I am still learning, and maybe in a few more months will feel more comfortable with my live presentations to go out on a YOUTUBE. Confidence grows with each presentation (try teaching 9th graders physics some time).

If you have a local club that is looking for an outside speaker, and can deal with this Nano VNA as a 9th grader, I'm your guy. I am not a professional RF engineer who has worked with VNAs his whole life.

If I can introduce someone to a new tool to have in their toolbox and learn as you go, that is enough for me.

Again, I do appreciate the pros explaining to me where a slide is misleading, or simply wrong.

I like the title now: The Nano VNA: An Antenna Stethoscope
(Like the EKG tells you something about the state of health of your heart if you know how to "read" it.
A VNA is one cool gadget

73
Barry k3eui
K3euibarry@...

Not to be offensive but have verified 3 volt and 5 volt power? LEDs lit>

Now let's go off the deep end -

how do you characterize ferrites and powder iron (rod and toroid) for useable frequency as inductors/choke, transformers, and wide band transformers?

Mike
N9XYP

All good ideas. Clubs are always looking for interesting programs.
Before Covid, our in-person club meeting would sometimes have a guest
speaker “live” via Skype. We have a projector and some speakers to see and
hear the remote presenter, plus a camera on a tripod so the presenter can
see the room. We also have a mic on a long cord to pass around for
questions. For presenters, it’s more work than a one time video, but it’s
much more engaging than watching a video too.
Thank you to all who take their time to share what they have learned, no
matter how they make it happen!

Chris, did you get the PDF version of the measurements? Those are the
final version.

I'd be glad to work with you on how I made the measurements. Many were
made using the HP 7653C and not the NANO. There is only one measurement
set that I can not adopt to the NANOs. Ask specific questions and I'll
answer.

Dave - W?LEV


On Wed, Feb 24, 2021 at 4:53 PM c suddell via groups.io <chrissuddell=
[email protected]> wrote:

Hi Dave,

Would love to have a chat to you about your results. I'd like to
republish your findings, but wanted to chat about how you came up with them.

Chris
M0VUE

--
*Dave - W?LEV*
*Just Let Darwin Work*

OK, was finaly able to get the NanoVNA-H in DFU mode and was able to find it in DfuSeDemo...

loaded the proper firmware DFU file and loaded it correctly as per the procedure...

the unit is still dead!...

While in DFU mode the Blue LED stopped flashing and did comeup in win10 as STM32 Bootloader like it should be...

the DfuSeDemo found the unit, I was able to load the proper firmware even did a VERIFY and confirmed it was loaded.

removed the jumper

rebooted the NanoVNA-H, blue led started flashing again and... wait for it... NOTHING

Just a white screen!

looks to me like the unit is not having firmware issues... instead I think this is a HARDWARE display issue???

comments or suggestions please

73

Richard VE2DX

ok!... Let me be clear... the unit was NOT loaded with -H4 firmware...

The unit was sitting on a shelf for a couple of months and when I pulled it out to use it it was... DEAD... Bricked... NOT WORKING... call ot as you wish it stopped working by itself not because I load -H4 firmware in it...

I tried running the DFU procedure and can not detect the unit, and yes I did follow the process to get the unit in DFU mode holding the Select switch while powering up, tried in all 3 possible position...

No I do not see any Jumplers on the pcb

I got myself an ST-Link V2 from Amazon, and I am simply looking for;

1- Software to download firmware in NanoVNA-H (Not using DFU!)
2- Proper site do download latest NanoVNA-H Firmware HEX file.
3- good site for step by step of the procedure

thanks for the help

73

Richard VE2DX

On 2/24/21 9:06 AM, Larry Macionski via groups.io wrote:

Barry K3EUI-
I appreciate your dedication to bring this effort to the group.
Obviously there is a Power Point version. You will be in demand when hamfests, return Shortly.
I encourage you to narrate a Power Point Presentation and place it on DVD for distribution at nominal cost to Clubs.
I spoke to the ARRL at a ARRL convention to promote such presentations that would be available like some sort of traveling virtual speaker.

Or post it on Youtube - No need for a DVD - someone can just download it and save it.

I would suggest getting some help for this. Someone who is familiar with recording, editing, and synchronizing against the slides can do it in the blink of an eye, but hard to do by yourself.

I like the idea but would suggest a USB drive instead of a DVD, as most laptops no longer have DVD drives and USB/thumb drives are quite inexpensive.


From: Larry Macionski via groups.io<mailto:am_fm_radio@...>
Sent: Wednesday, February 24, 2021 12:07 PM
To: [email protected]<mailto:[email protected]>
Subject: Re: [nanovna-users] Nano VNA: An Antenna Stethoscope ( pdf file latest edition de k3eu )

Barry K3EUI-
I appreciate your dedication to bring this effort to the group.
Obviously there is a Power Point version. You will be in demand when hamfests, return Shortly.
I encourage you to narrate a Power Point Presentation and place it on DVD for distribution at nominal cost to Clubs.
I spoke to the ARRL at a ARRL convention to promote such presentations that would be available like some sort of traveling virtual speaker.

Of course any Idea that takes the ARRL into the 21st century falls on deaf ears. But I would pay easily $20 for a copy that I could use at a club meeting. I am a member of 3 clubs, and trust me, without some sort of presentation such as this would be; those meetings are like watching paint drying. OK now we'll vote on the Treasures Report. All those in Favor?? Why even bring it up, unless the treasury is $0 and - I assure you there would be no Treasurer giving that report of ZERO funds.. Is it any reason, the next generation is not interested in ham clubs and meetings.
W?VFW is now going to alternating monthly meeting with an activity. March will be the 1st meeting since the China plague.

Larry W8LM
ARRL LIFE MEMBER - Licensed 55 years.
VFW post 3115 Amateur Radio Club, W?VFW -Wichita, KANSAS
Past President 2 terms- VE Team Leader 12 years - Training officer.