Sorry if this has already been discussed but I cannot find it.

On the nanovna group there has been a thread concerning the installation of a Bluetooth module to control and send scans remotely. It required firmware mods to activate a uart on the device and then connection of the dongle to four points provided on the board of later versions.

Is there a possibility of doing this on the V2?

Steve L. G7PSZ

It not possibly on V2, only if made hardware and software mod

on V2 no free pins for serial port:
PB10 and PB11 can be use as serial pins (hardware usart2 on CPU can be connected to it) PB11 used for S1 button, and need move it to for example free PB9)

PS i can mistake

so the real answer is ... adding a bt module is possible if you use pb10
and pb11 ... rewire the button s1 to pb9 ... and do a complete firmware
change so that the soft knows where the button now (after rewire) is
connected to and you have to activate the usart2 ...

if the firmware could "check" the usart2 (is there a bt module present)
and would then "automagicalli" use pb9 for s1 ... that would be perfect

if a user has added a bt module and did the rewiring of s1 ... then use
pb9 as s1 input (and activate usart2) .. if the check of the usart2
fails (no bt module added) then let the soft use the "normal" usage of
s1 input ...

problem may be that the bt module may add some noise in the 13cm area
... means if you measure in that area then you should switch off the bt
module ... but then the "usart check" would fail and your s1 button does
not work ... hmmmm ... something to think about?!?!?

so ... to sum it up ... adding bt to v2 should be possible ... but its
tricky and may need a bigger firmware change plus a rewire of s1 (not to
mention the maybe added noise in 13cm that may influence your performance)

i have TWO ... and one is my "test bed" for such things ... and i would
like to add a bt module if possible

just for testing and if that works fine then add it permanently?!? ...

so dislord ... i am no programmer (but a clever hardware modder) ... if
YOU could do the fw change (and maybe send me a test fw in direct mail)
then i would try the modding here :-)

if results are good (and if we can make the above usart check to make
the s1 rewire find out by the fw) ... then we could add that to the fw
for all users ...

i have a bt module in my sark100 ... and to measure "wireless" ... or
besides the pc use the smartphone to display a sweep is superb for
outdoor usage fieldday etc ... so if a similar thingy would be possible
for the v2 ... why not try it?!?

think about you wanna measure somethink on your workbench ... but the
shack pc is on the other end of the room

on the sark 100 the bt module and the usb chip share the same pins ...
means i had to switch off bt modue when usb is connected ... but that
could be easy solved with a p channel fet (IF USB 5V IS PRESENT SWITCH
OFF BT) ... but here we have a second usart ... should be not "tooo
difficult" to add a bt module then ... NOT?!?

just some things to have a bit to discuss ... what do other think?? ...
("hey who writes a smartphone app like the one i have for the sark?")

greetz sigi dg9bfc


Am 03.10.2020 um 14:33 schrieb DiSlord:

> It not possibly on V2, only if made hardware and software mod
>
> on V2 no free pins for serial port:
> PB10 and PB11 can be use as serial pins (hardware usart2 on CPU can be connected to it) PB11 used for S1 button, and need move it to for example free PB9)
>
> PS i can mistake
>
>
>
>
>

Dear Seigfried,

You have basically answered my question. Even if I modded my vna and got some bespOke firmware, I would be forever locked into that firmware.

Would an alternative be to make a dongle to plug into the usb and send remotely that way? It would potentially be useable on multiple devices. Failing that, a very long usb lead ( with choke ferrite at the vna end) into a laptop might be the way.

Personally, I would be very wary of embedding YET another strong source of RF, into a sensitive wideband instrument like a VNA. The potential for generating internal mixing products (especially from harmonics), and also raising noise levels, is quite high!
-Hector

I not see noise on enable Bluetooth module on measure. This feature optional, In some cases, you need the ability to remotely manage, and this solution allows you to do. You can disconnect/power off module in any time.

Also you can connect to serial any serial control devices and send command to it over USB connection

Yes but there are problems in certain situations.

I cannot remember what the maximum length a usb cable will work over, so as to have a laptop running nanosaver or similar on it, but it is only 5-10 metres I think. I presume the V2 uses usb A or possibly usb B. Is there a way to slow it down to the 10mbit speed?

The usb terminations are obviously digital so no chance of optimising at either end other than using a good usb cable with twisted pair wires (I think - many will know better than me).

Oh well, a project for rhe middle distant future.

Steve L. G7PSZ

@DiSlord
"I not see noise on enable Bluetooth module on measure."
Thanks for confirming it. Doing something is certainly the good way to find out!
-Hector