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OK,
I wandered the group site for a long time and went to the HOW TO on the wiki site, Nothing helped me.

I have the steps for measuring an inductor down solid. And have probably done a hundred by now.

But I now want to measure a variable cap. to learn it's max and min values.

But not having any success on how to do that.

Anyone?

Joe WB9SBD

Since the STM32F303CCT6 is currently difficult to order, some clones may be replaced with some inexpensive processors.
Earlier versions of the NanoVNA-H4 firmware, which allows only 101 scan points and uses relatively little RAM in order to remain compatible with the NanoVNA-H, can also run on the STM32F303C8T6 and STM32F303CBT6 as well as the STM32F302C8T6 and STM32F302CCT6.
The new firmware takes full advantage of the STM32F303CCT6 RAM and ROM with more scan points and save options with the help of DiSlord, so it can only run on the STM32F303CCT6 and STM32F302CCT6 which have larger memory.

Stephen
I found the functional block diagrams of both F302 and F303 series processors, if you're interested.
Again, a lot of the chip's internal functionality is not used. The F303 was originally chosen due to its ability to drive a 4 inch display which the F072 in the original design could not. The STM32F303CCT was also a pin for pin drop-in replacement for the F072 and available on an STM32 experimenter board.
More info: /g/nanovna-users/topic/61079748#9206

Try installing DiSlord's latest H4 version of FW - 1.0.69 - on the unit, calibrate it and check out all the functions including screen brightness control and battery charge sense. I don't think you'll have any issues - but again, if new software functionality is added to the H4 in the future that depends on something that the F303 has and the F302 does not (like memory), then return it.

BTW - what's the complete processor part number, including suffix? A real H4 uses an STM32F303CCT6. If you have a GD32F303 processor, return it. With more info, I can update the forum's Wiki about this model and list any caveats associated with the device.

Your call.

Larry Rothman

Thank you for your thoughts. I was unaware that the full functionality of the MCU was not needed. Personally I take the view that if a manufacturer attempts to replicate a product in appearance, packaging, branding etc., it may be deemed a counterfeit. But as you say "that doesn't mean it won't work"

That is an unknown clone. I've never seen that processor in one of these before BUT that doesn't mean it won't work.
The nanoVNA only uses about 30% of the internal peripheral ability of the chip (timers/FPU/memory/etc) as many areas/functions are not needed.
I have attached a chart of the STM32F3xx family below and there are several subgroups to each product line as well. look here:
However, the final say is up to you and personally, if the ad specs an STN32F303 and you didn't get that, I would return it as 'counterfeit'.
My $0.02

I purchased a "NanoVNA-H4" from Amazon in the UK. The brand is Hima, supplied by ANGLO CT. I purchased from Amazon to try to avoid delivery delays and unexpected import costs. I opened the back of the device to find there is no QR code or version no. But more significantly the mcu/processor is an STM32F 302. I understand the "302" part is a lower spec than that used by the official Hugen product.

I don't "need" the device for immediate use, so should I return it?

Thanks.

Compensation for the delay is part of the normal calibration. You only
need to set the delay separately to compensate for a cable or connector
length that can't be part of your calibration.

On Tue, Sep 14, 2021, 5:05 PM lobos305 via groups.io <lobos305=
[email protected]> wrote:

I always calibrate with as many connections and cables attached as I can
to eliminate insertion loss. I never considered delay as a factor, which I
will now have to research.

witch pin do I check and what should it read?
Wayy too small traces for my multimeter so I have to go lend some smaller stuff tomorrow.

you need check output switch u551, see v2 scheme

nope. does not matter if the frequency is 3mhz - 6mhz or 140mhz - 455 mhz or full scale etc...
Always the traces are all around the place.

Your device work in < 140MHz?

Check work in < 140MHz on V2 and V2Plus firmware

If work, problem in ADF generators or switches

not sure how quoting works here but @Larry Rothman
From the link above. I installed the v2.2 firmware. The one that is not sold anymore. Problem is still the same
Then I installed one above it (v2 plus v2.3) Tried both experimental and stable. problem is still the same
Tried the V2 plus4 and the firmware does not work and have to force dfu and reflash something else...
Also tried all the "unoffical hardware variants"

Valinire in previous post said to use the following for the s-a-a-2

One is the comm port and the other is the firmware

Here is the links



S-A-A V2





De K8HTB Joe

Config-version only displays the version of FW you installed into the device.
If you installed plus FW into a non-plus device, you will see 'plus' on the version screen.
So - you need to install the non-plus FW into your device and calibrate to see if the problem goes away - if it does, you have a non-plus device.

Config - Version says NanoVNA v2 Plus.
I just tested ALL the firmwares listed on that site I linked.
2 of them did not work at all, 2 were super slow and rest were working but still with my problem.
frequency range is 100mhz-150mhz.
Tried many different of them.
What should the scale/ and div etc... values be? Seems when I play with them I get better looking traces but the resistance values for example still changed all the time.
SOmetimes -6ohm to 20ohm. sometimes its 48ohm - 51ohm

Are you sure you have a plus version? The firmware for regular V2 and V2Plus is different (but work, not good work).

I tried with those sma calibration things and I also calibred with 50ohm resistor
I also tried open so without any connection
short, I shorted sma center to threads
and load was 50ohm resistor

Firmware is downloaded from here
20201013 stable for v2 plus

There is a similar effect when you upload the plus version firmware to the non plus hardware.

The saa-2n doesn't use dfu for flashing.?
Please search the forum messages for: SAA-2N firmware?
And you should find the info you need.?
Please remember that this forum is primarily for the NanoVNA devices. You should have a look at the SAA specific groups for info on your unit.?


On Tue., 14 Sep. 2021 at 9:33 p.m., Chris Pohlad-Thomas<chrispohladthomas@...> wrote: So I tried following the procedure in the absolute beginner guide in order to update the firmware on my SAA-2N. I noticed when connecting it to my PC it shows up as USB Serial Device (COM3) and when I put it into DFU mode I do not see anything change in Device Manager. I did notice when I went to look at the version that there is no information in there. Is the procedure different for updating these?

So I tried following the procedure in the absolute beginner guide in order to update the firmware on my SAA-2N. I noticed when connecting it to my PC it shows up as USB Serial Device (COM3) and when I put it into DFU mode I do not see anything change in Device Manager. I did notice when I went to look at the version that there is no information in there. Is the procedure different for updating these?