NanoVNA V2 / Forum

Note: this page is a mirror of
Click here to join and see most recent posts.

firmware for V2, it contain most features from H/H4

DiSlord 2021/04/04 10:01

I try port most code from H/H4 (not finish, but... it work)

- rewritten control code si53351 (ported from H, almost unchanged, only work on harmonics is cut out)
- accelerated work on the i2c bus with si53351 (it is software, but the decrease in delays made it possible to speed up the work of the si5351)
- accelerated work on the SPI bus with ADF (it is software, but the decrease in latencies made it possible to speed up the work with the ADF4350)
- new measurement timings are installed
All this made it possible to understand the measurement speed by a factor of 2 (and for SI up to 140 MHz by more than 4 times), you can further increase the speed by choosing AVGx1 (by default 2x), this will still increase the speed, but at the cost of a slight deterioration in quality at high frequencies
For V2 / V2Plus frequency step up to 140MHz - 1Hz, above 140MHz - 375Hz
For V2Plus4 up to 140MHz, it seems like 10Hz, above 10k (it seems like this code is hidden, I can't say for sure)

Now for the rendering and interface
- ported the code for drawing the screen from H, this gave in some cases more than twice the screen refresh rate (especially when there are many long lines), not to be confused with the measurement speed
- added track | Z |
- the FPU module is used for calculations
- removed unnecessary buffers and so on, this allowed the free memory to be used to increase the number of points to 371
- the UI system has been redesigned, which made it possible to move the markers with the rocker, change the type of graph, size, and anchor point on H when paused.
- The Time Domain code has been rewritten, it is 2 times faster (and taking into account FPU, about 10 times)
- full support for NanoVNA-App for control from it
- add 6 markers support
- add grid text (DISPLAY->SCALE/DIV )

This is from the main one, which I don't remember yet, I ported almost everything from H, the main thing was that I wanted to speed up the work and remove the annoying impossibility of working with a rocker to set markers during a pause (well, and change the track)
The main thing I work with is V2Plus, so on a regular V2 I could miss something.

Once again about the timings, the new AVGx2 mode is analogous to the old AVGx1 in quality (the new AVGx1 mode speeds up, but at the expense of a small loss of quality)

ATTENTION the firmware is compiled with FPU enabled, so if you have FPU version on the screen - no, they will not work (later i compile some fw vs disabled FPU support)

C.M. 2021/04/04 17:10

Amazing work ! Thank you for not forgetting the v2 owners !!

Jean-Roger Roy 2021/04/05 02:49

Thank you for this great work, and for all what you do for the NanoVNA and tinySA community. It's really outstanding.

Just one question : I think it is not possible to put here the variable RBW function. Is it related to available commands, or something else ?


DiSlord 2021/04/05 03:37

Exist Display->Avg option, it analog of rbw (but different device use different tables/size for calculation correct RBW can`t show in options)

Jean-Roger Roy 2021/04/05 04:06

Ok, thank you for your explanation. It remains not so accurate as for a H4, but quite useful.


Stephen Laurence 2021/04/07 07:41

It sounds like a massive undertaking.

It seems that dynamic range will be improved slightly with a significant increase in sweep speed.

Have you kept the pulsed signal which seems to be a feature of the v2 architecture so as to facilitate ecal? The reduced frequency step size will enable a worthwhile improvement to narrow band sweeps, but will it enable measurement of crystals?

Steve L

DiSlord 2021/04/07 08:16

V2/V2Plus can measure crystals (frequency step up to 140MHz, 1Hz) vs some limits V2Plus4 not

Here crystal measure on V2Plus:

here is V2Plus4 crystal measure try:

DiSlord 2021/04/07 13:33

No, this screenshot from test version (i want understand how it work on more points) in it not possible save calibration (as can see not calibrated)

Siegfried Jackstien 2021/04/07 21:45

ah ok ... understood ... you made it just for tests ...

aehem .. what about also add some avg on the plus4?? should smooth the
curve out a bit i think

greetz sigi dg9bfc

ps how was your setup ... any pictures or a description??

Am 07.04.2021 um 20:33 schrieb DiSlord:

Aleksander Shalygin 2021/04/10 10:24

Test 3000 - 4500 MHz

Siegfried Jackstien 2021/04/10 17:36

a good 9cm filter ;-)

dg9bfc sigi

Am 10.04.2021 um 17:24 schrieb Aleksander Shalygin:

Stephen Laurence 2021/04/10 10:42

Er, yes, and you have broken through the 4.4ghz limit of all the v2 nanovnas.
I thought it was a hardware limitation.

Steve L

Siegfried Jackstien 2021/04/10 17:47

the hardware limit is "around" 4.45 ...some a few megs higher some a bit

4.4 g left enough safety margin

dg9bfc sigi

Am 10.04.2021 um 17:42 schrieb Stephen Laurence:

mce66 2021/04/10 12:50

in the highest part of the passband I see a S21 higher than 0 dB. This looks a calibration error, since the filter cannot amplify. Did you calibrate with a kit able to go to 4 GHz?

pjzzz 2021/04/19 05:32

Hi Dislord,

Keep up the good work. I love the screen layout and speed improvements you've made.
Waiting for future updates on this project.

To reply to this topic, join

View this thread on