NanoVNA Custom Software

[radiolistener]

Hello radiolistener:  I sent a message to my EBay seller telling him that I want to return it for either a full refund, or a current replacement unit.  Because this one has obsolete Firmware, Green LEDs where they are normally Blue, and only 2 Traces are available where as it should be 4.

1) All devices that you may buy on the market has outdated firmware. If you want fresh firmware you're needs to update it by self. You cannot find device with fresh firmware on the market. The update process is pretty easy. Just click on the button "Choose" at the upgrade section of DfuSE Demo tool. And select file with firmware. That's it. Two mouse clicks and your firmware is updated.

2) All devices on the market have different LED color, there is no standard color. You can find exactly the same NanoVNA with red, blue or green LED. They all the same. Just random color of LED.

3) two traces come with old firmware. Just update it and you will have 4 traces. It takes for about 1-2 minutes. Nothing difficult.

[ted572]

1) All devices that you may buy on the market has outdated firmware. If you want fresh firmware you're needs to update it by self. You cannot find device with fresh firmware on the market. The update process is pretty easy. Just click on the button "Choose" at the upgrade section of DfuSE Demo tool. And select file with firmware. That's it. Two mouse clicks and your firmware is updated.

2) All devices on the market have different LED color, there is no standard color. You can find exactly the same NanoVNA with red, blue or green LED. They all the same. Just random color of LED.

3) two traces come with old firmware. Just update it and you will have 4 traces. It takes for about 1-2 minutes. Nothing difficult.
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OK Great, that is good news.  I will go ahead and update the FW.  Tnx again

[xrunner]

2) ST-LINK update. This is native and reliable way. But it requires ST-LINKv2 dongle. This dongle allows to flash even bricked device and also allows to use in-circuit debugging.

For ST-LINK update, you will need the file with HEX or BIN (any of these) extension:  nanoVNA_900_ch_20190920.hex

Thanks for the tutorial radiolistener, I am getting a NanoVNA soon and I just ordered the ST-Link according to your instructions so I can get the firmware updated as needed.

 

[radiolistener]

OK Great, that is good news.  I will go ahead and update the FW.  Tnx again

Before update, save your current firmware. Just in case if you will want to rollback to old one.

[ted572]

Hello radiolistener:  I just removed my NanoVNA's bottom cover to locate the 'Boot Jumper'.  I found it, although the label for it is under a white nylon plug for the Battery (that I haven't seen on any other unit's in the YouTubes(?)).  But the big thing I noticed is that there are no Internal Shields on my PCB as all the other units have (as shown here in the picture from a YouTube).  Again my unit has no shielding where you see it here.  This seems potentially serious(?).  What do you think?   Ted

Edit: I added a picture below of my unit without any shields.

So now of course I wonder if I have a  1. Older unit, 2. Newer unit,  3. Unfinished Older unit, or 4. Unfinished Newer unit?

[amspire]

So now of course I wonder if I have a  1. Older unit, 2. Newer unit,  3. Unfinished Older unit, or 4. Unfinished Newer unit?

It is pretty close to the layout of the one I have.

The shielding problem is easily fixed.

Just buy some thin shim brass. You can cut it with scissors (as long as it is not someone's prized sewing scissors!) and it is pretty cheap. A dollar or two. Any machinist supply shop or ebay has it.

The bigger shield is in two parts - I have attached a photo.

Richard

[joeqsmith]

I had upgraded the firmware when I first received the Nano but it had a few problems.   One in particular was causing me some problem where every now an then, the data was corrupt.    When I wrote my software, I was seeing the problem more frequently than with their software.   

Basically, it seems the firmware could be running a sweep at the same time they were dumping the data and it would corrupt the packet.   Throttling the data rates helps which may be why they chose to run the supplied software so slow.    Even with slower rates, there were modes I could get the firmware into where it was very unreliable.   If I pushed it too hard, the screen would go white and require a power cycle. 

If seems that the person creating the firmware was aware of this problem and changed how the unit handles the messages.  I have spent several hours testing the new firmware and it has yet to glitch.  These tests were with my software running unimpeded.   The screen updates are faster now.  They also added some very nice features to the new firmware.   Well worth the time to upgrade.   

I'm not sure if they have added any new commands but it seems compatible with my software and I am guessing it's backwards compatible.    I wonder if they did not also correct the screen artifacts as I haven't noticed it since the upgrade.   

I also designed this simple driver to control that old Transco transfer relay I had.  The relay is a latching type that runs from 28V.   So the board is a DC-DC boost converter and a couple of one-shots made out of a hex inverter.   It just runs from the same FTDI TTL cable.  This relay works really well.   Isolation is no longer a problem.  They are fairly common in the used market for under $100.  PN is 700C70200.

[radiolistener]

There is fixed spike at 300 MHz for measurements in the latest firmware.

Also now it allows to measure up to 1500 MHz. It has higher error above 1200 MHz, but still can be used for antenna tuning.

Also added battery indicator. It shows empty battery, if you want to use it, you're needs to install diode on the pcb. See picture above.

Also I hear that there is added command which allows to get raw data with any desired point count, but with no calibration. It can be used for measurements on PC with custom calibration process. But I'm not sure if this command is present in this firmware (didn't test it yet), may be it will be available in the next release.

[radiolistener]

So now of course I wonder if I have a  1. Older unit, 2. Newer unit,  3. Unfinished Older unit, or 4. Unfinished Newer unit?

I know about this version. People install home made shielding and it works the same as other units. But no shielding may affect measurement results.

So, you can ask partial refund for missing shielding and make it self. This version even better, because it has continuous shielding pads around mixers area, while old units have just small pads (it leads to worse shielding).

[ted572]

I received the following link from the seller of my NanoVNA: https://github.com/ttrftech/NanoVNA?tdsourcetag=s_pcqq_aiomsg
I don't see how he would think that this would be of any interest to me, but perhaps it is to a software guy(?).  Its a public post, so probably nothing new to those that follow this web site.

[joeqsmith]

I have yet to try running it above 900M.  The calibration would not be a problem as I do this with the PC.  Running a T-check above 500MHz even with the higher quality Transco relay doesn't yield good results.  I have a few filters that work in that 900M to 1.5G region that I'll try with it. 

I'll look into their higher resolution scanning.   I had just assumed this was a limit due to the hardware.  I assume it proportionally slows down the scans but it may be faster than my segmented scanning. 

For now I am more interested in seeing them fix some of the problems.   After watching the Nano's display, it appears the artifacts (left over segments from a previous scan) are still there.  However, the new firmware continues to be glitch free.   By far, this was the best change IMO they made to the firmware.     

The unit I have always had a problem at 300MHz.  Above 300 the results are pretty much what you would expect from a $50 unit.   

Showing data I had collected using the July firmware compared with with the Sep release.  The data was collected using the same cables and 50 ohm load.    Note that the instability around the 300MHz is reduced.   

   

[radiolistener]

I'll look into their higher resolution scanning.   I had just assumed this was a limit due to the hardware.  I assume it proportionally slows down the scans but it may be faster than my segmented scanning.

the new command doesn't apply calibration to the result. It returns just a raw measurements. You're needs to calculate calibration coefficients and apply it on the PC.

The unit I have always had a problem at 300MHz.  Above 300 the results are pretty much what you would expect from a $50 unit.   

My unit also had a high spike at 300 MHz. With the latest firmware from 20 september it is fixed.

[joeqsmith]

I'll look into their higher resolution scanning.   I had just assumed this was a limit due to the hardware.  I assume it proportionally slows down the scans but it may be faster than my segmented scanning.

the new command doesn't apply calibration to the result. It returns just a raw measurements. You're needs to calculate calibration coefficients and apply it on the PC.

From my previous post:

The calibration would not be a problem as I do this with the PC.

This is how I was able to use the transfer relay to perform full 2-port measurements.   As I stated, it's really no problem.   The attached pictures show an interdigital filter being swept above 900M.   Seems to work.  I'll play with it more later.

The unit I have always had a problem at 300MHz.  Above 300 the results are pretty much what you would expect from a $50 unit.   

My unit also had a high spike at 300 MHz. With the latest firmware from 20 september it is fixed.

From your previous post,

There is fixed spike at 300 MHz for measurements in the latest firmware.

I interpreted fixed to mean recurring or stationary at 300M, not meaning they improved it.    Good to know that your unit also shows improvements.

[joeqsmith]

I made an attempt to try the Scan command using the comments below.  The Nano responds with a "?" which suggests that it does not understand the command or the syntax is invalid.   I've been avoiding looking at the firmware but it appears that this is really the only source of documentation for it.  Github seems to be down at the moment but I'll have another look later.   

 

I added one command to the eddy firmware to enable on demand scans of
arbitrary length (yes, you can scan with one million steps or much more if you want)

Usage:
First pause the continuous scanning with "pause" and the use the "scan" command
to scan [from frequency in Hz] [increment frequency in Hz] [number of steps]
The frequency increment step is for now an integer
The scan command outputs

start
frequency s11_real s11_imag s21_real s21_imag
done

during the scan the calibration is NOT used so the output are uncalibrated numbers
allowing alternative calibration strategies

Example:
ch> pause
ch> scan 5000000 20 5
ch> start
5000000 0.001503840 0.000420701 -0.306770563 0.018568072
5000020 0.000695601 0.000503197 -0.306792527 0.018579231
5000040 0.000532656 0.000520238 -0.306793421 0.018573865
5000060 0.000495833 0.000512704 -0.306819111 0.018593480
5000080 0.000520689 0.000523833 -0.306812644 0.018576323
done

ch>

[joeqsmith]

Typing Help, Scan is not listed as a valid command.   Makes sense.   Github was back up so I downloaded the source and had a look at Main.c   

    { "gain", cmd_gain },
    { "power", cmd_power },
    { "sample", cmd_sample },
    //{ "gamma", cmd_gamma },
    //{ "scan", cmd_scan },
    { "sweep", cmd_sweep },
    { "test", cmd_test },
    { "touchcal", cmd_touchcal },

So while it looks like they may have considered adding this feature, it is not supported.   There may have been no benefit to something like this versus using my segmented approach.    Still, the upgrade is well worth it just for that one bug fix.   The system is now fairly stable. 

[radiolistener]

yeah, just tested, it is missing from the firmware 20-SEP-2019, so it will be added in the next release

[joeqsmith]

After adding 900M-1.5G into the mix, the noise from 500M to 900M doesn't seem so bad.   

Video clip showing the scatter plot:
https://www.youtube.com/watch?v=1xzNyqJ1T30&feature=youtu.be

[joeqsmith]

I have some abilities to filter the data.   Shown with a simple smoother.    There no penalty for the screen update rate as it ran across individual scans.   

https://www.microwaves101.com/encyclopedias/smoothing-is-cheating 

I should mention that I have yet to try averaging the data.  The problem is how slow the Nano is.   Early on, I had tried a few things, like turning off all the traces to try and improve the sweep rates but it appeared to be fixed.   With the new firmware, it's slightly faster because I no longer have to throttle the data rate to keep the Nano from sending bad data.  Still, the improvements are not significant enough to try and average the data. 

[Bicurico]

"NANOVNASAVER SOFTWARE WALKTHROUGH + NANOVNA FIRMWARE UPDATES BRING 1.5 GHZ MAX RANGE"

https://www.rtl-sdr.com/nanovnasaver-software-walkthrough-nanovna-firmware-updates-bring-1-5-ghz-max-range/
https://github.com/mihtjel/nanovna-saver
https://github.com/ttrftech/NanoVNA

[Bicurico]

I compiled the firmware - not tested, yet - and it does compile without errors.

Attached for everyone's convinience.

Update: Just noticed i can't flash this, as it is not a DFU file! The instructions are wrong for compiling/flashing this. Don't want to use the ST-LINK V2 right now...

The FW that was linked a few posts earlier already increases apparently up to 1500MHz - I just did not try.

Also, while compiling works, I end up with a *.bin file instead of a *.dfu file. The difference is of course that teh DFU mode expects a file with the the corresponding headers, which are not present in the *.bin file. How do I compile a DFU file?

Regards,
Vitor

[joeqsmith]

People still ask for my LabView interface but I'm not sure why.  The open sourced Python seemed to really be what people were asking for and it certainly seems like they have made a progress with it.   Anytime I've asked what features they are missing, I never get a response.  They may just not be aware of the open source project.   

[Bicurico]

That's the point: I first saw people asking for feature and considered it an opportunity to write a donation-based software.

But then I looked at the existing applications and found them to be of a pretty high quality, so I asked people what they were unhappy with.

The only one responding was you, mentioning the not so nice screen refreshing. Other than that, I got no reply.

Then I thought I could implement the single feature I was not seeing: being able to sweep with more than 101 points. While I did implement that (slow), I noticed that this project I linked today, already does that, too! And there are FW forks to implement the sweep command you mentioned.

This is why I basically gave up on developing anything for this device: there are already too good alternatives!

Regards,
Vitor

[joeqsmith]

I added that narrow band or what I now call segmented sweep to increase the number of data points when I was working with SPICE and trying to get a decent demo going for that third video.   It will be very interesting to see if this new high resolution sweep will improve things or is it going to be so slow it is useless (much like my segmented sweep).   

I noticed they appear to have information about building the source with Windows but I haven't tried it.  I did however get the screen to go white again today and had to power cycle the unit.  So it's more robust but still could use some improvements.   

Sigilent's website shows them taking orders for their new VNA.   $3400 or so USD, without the cal kit, no TDR and no VNA software included.  Look like you more into the $5K when it's all said and done.    Plus you still have the problem of it not being a full 2-port system.   Hoping this time around that they give the unit to people who can actually show the practical justification of the higher cost when compared with this $50 unit.    

https://siglentna.com/spectrum-analyzers/sva1000x-spectrum-vector-analyzer/

[joeqsmith]

TOKO America, PC# 4DFB-915E-10=P
Description   Value      
Maximum Insertion Loss   2.7 dB      
Cut-off/Nominal Frequency Upper Range   800 to 1000 MHz      
Cut-off/Nominal Frequency   915 MHz      
Impedance   50 Ohm      
Maximum Pass Band Ripple   1 dB      
Operating Temperature   -40 to 85 °C      
Category   Filter Misc      
Manufacturer   TOKO America

https://www.digchip.com/datasheets/parts/datasheet/484/TDFM2B-915E-10_P-pdf.php

[joeqsmith]

I spoke too soon.  While playing around with this filter, I had the screen once again turn white which required a power cycle to recover.   Worse, I am once again seeing corrupt data sets.   This is not just my software.  I see it happen on the Nano's screen as well.  Slowing it down does appear to help.    Maybe it has something to do with the span, or the fact I am straddling the 900MHz region. 

Oh well, I was being too optimistic.  Hopefully the people working on the firmware can get something robust.