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I happened to find a little stylus last night that I rembered being included with a resistive touch screen I bought for tinkering a few years ago (I tried to find it before, but couldn't locate it), and tossed it into my 3D printed case with the USB cable.? I agree - it would be nice to have a little sleeve area to slide this into on the tinySA itself.? I actually found it in a 3D printed case I did a while back for a fan controller with a touch screen interface for my 3d printer enclosure.? I had modeled that with a protrusion on the side with a hole to store the stylus.? :-)

With regard to your comment about the audio jack, someone has already done this.? Check the files section of this tinySA groups.io - I happened to see it there last week when I was poking around here.

Thanks Herb for the reply. You've confirmed my suspicion that the letters stand for certain parameter settings, but I was hoping to know specifically what each letter signifies, and the difference between lower & upper case.

Thanks...

Ya know, since you started this one... I wonder if there could be a replacement case for the actual device in the works? I say this because the new functionality of having audio output so one can listen to a signal might be a good reason to print a modified rear case that's a little thicker to accommodate an 1/8" audio jack.? You might be able to keep the current top half of the case and just come up with a replacement bottom half that's deeper.? Just a thought.

And since we are dreaming, I had a cell phone case one time that had a small hole in the edge you could slip a small 2-3" stylus into. That to me would be far preferable to the guitar pick option.

Thanks,
Sean

Very nice! Looks like there is room for a DC-block as well.
Too bad my 3D-printer is only 14x14 cm, and it doesn't work to print a scaled down version either... :-)

On Fri, Jul 30, 2021 at 01:58 AM, mikemm58 wrote:

Sorry if this has already been a topic, but I'm wondering what the meanings of the letters on left side of screen denote.? This would be the string of letters just under LOW (or HIGH) . For example mine shows "afrgnb".? I imagine these are to show some sort of status or parameter selection.
Any help appreciated!?

? ?Erik replied to an identical question in message?/g/tinysa/message/5294 .? Through observation you can determine the letters indicate whether different settings are manual or automatic or enabled or disabled.? In manual mode certain letters change to upper case,

? ?The letters help Erik to troubleshoot user issues by being able to see which significant settings have been changed.

Herb

Sorry if this has already been a topic, but I'm wondering what the meanings of the letters on left side of screen denote.? This would be the string of letters just under LOW (or HIGH) . For example mine shows "afrgnb".? I imagine these are to show some sort of status or parameter selection.
Any help appreciated!?

Thanks

The filters are not Gauss shaped. This signifcantly would improve settling and sweep time.

You're welcome - I enjoy working on these sorts of projects.? I hope it works out for you.

I've printed the top, now printing the bottom. Looks good so far, thank you for all of your effort on this.

As it happened I spent a large part of the day looking at the RBW filter responses using a couple of tinySAs. I don't see an issue. The 300 kHz and 600 kHz filters are the only ones that have issues. The rest are textbook perfect. Might be beneficial to evaluate the other possible RBW values. Then again, the picture I got from the tinySA is SA mode might not be accurate.

Electronic filters have a nomenclature and taxonomy and are a rather recent invention ca 1930's. I'm accustomed to using them as well as some other taxonomies.

Based on my tests today, I don't think significant improvement can be made except as part of a broader push for greater accuracy and dynamic range.

I continue to be staggered by the performance of the tinySA in all modes.

Have Fun!
Reg

AN415 mentions IF filter bandwidth in a couple places (around page 34). The SI4332 data sheet has some info on page 64 table 12. (See register 0X1C)

There also exists a spreadsheet on the website that calculates register parameters.

-Ray WB6TPU

Hi Toni
if you try at 950 MHz and various frequencies output is correct.Of course I calibrated before the 10 MHz, with a ribidium standard and 12 digits counter.
This is really a bug at 960 MHz. With other firmware is good.
Sandro

Sandro, you can correct the ref.frequency oscilator (for his internal calculations) of tinySA by MENU setting:

CONFIG - EXPERT CONFIG - MORE - MORE -CORRECT FREQUENCY? and enter, in your case 9.998307M.

(9.998307 is referred to 10M as 959.8375 is referred to 960M)

See this video?

enjoy!

I looked all through the datasheet and AN416 but could not find the filter details. I looked at everything on SiLabs.com that looked relevant.

Reg

There is a very limited set of parameters that "tune" the filters.?
Parameters are:

• Optional decimate by 3
• Decimate by 1,2,4,8
• Select one of 15 precalculated filters

I'm using the recommended combinations to get 57 BW filters.

Thanks.
--

Hi Erik
Setting 960 MHz high output real is 959,8375.
At self test end below " touch screen to continue" there are a little funny lines.
Apart from these, last FW do a great job.
Thank you.
Sandro

On Tue, Jul 27, 2021 at 01:24 PM, Reginald Beardsley wrote:

In what domain are the filters implemented? What are the coefficients for the operator?

Reg,
? ?See the following Wiki page??

? ?The?tinySA resolution filters are digital FIR filters implemented as DSP code inside the RX SI4432 so its probably best to download the datasheet for that chip to get a detailed description of their algorithm.? I'm not certain how much of that information is proprietary.

? ?The filters are selectable via a register location within the?RX SI4432.? Not much more can be done with them beyond that.


Herb

I sent them an email asking if their package worked on Linux.? Hopefully it will be so.? If not, is there no other way to compile it for Linux with another compiler?? I have compiled a program once before, but at the time, I didn't know that that's what I was doing.? I don't know anything about programming, but I can follow some instructions.? It would be great if we Linux users could have the apps too.? Thanks.

Yes I continue slowly.? Progress is glacial compared to Erik :)
To be clear to others, the simpleSA version runs on a different processor (ESP32) and the initial motivation was to see if I could make an analyser that could be used and controlled via the web from a standard internet browser using the WiFi features of the ESP32.? It proved to be possible though it took a few months to work out why the wifi stopped at certain points in a sweep - turned out the fifth harmonic of the LO was blocking the WiFi receiver!

I also designed a set of PCB, using KiCAD.? Of course there were a few mistakes but easily fixed.? My boards are a little more cramped than Gyula's as I wanted to keep the two boards within the 100x100 for low cost PCB from JLCPCB, and I wanted all the connectors on one edge.? ?I have some of the 30MHz Si4432 clock getting in unfortunately.? The 350MHz low pass filter also needs some optimisation.? As another learning exercise I also designed a 3D printed case with cover/tilt stand using TinkerCAD?which a club member kindly printed for me.

In this build I used different frequency SAW filters and different IF for the second pair of Si4432.? With no cable connecting the TG output to the SA input you cannot tell if the TG is on or off even with RBW @ 2.6kHz.? An additional RF switch is also included to change from the low frequency range input to the high range input.

Photo below with the tracking generator being used to measure a QRP-labs bandpass filter for 20m.

I am thinking of designing another PCB set with a common clock source for all four Si4432, and where the Si4432 would be soldered directly to the PCB rather than use the ready made modules.? Not sure if buffering is needed for the clock yet and having trouble finding a low cost 30MHz TCXO - any sources anyone?? Given the limited frequency resolution maybe a TCXO is overkill.
Next plan for software development is to enable the second set of Si4432 to be used as a second SA channel, then it could be used either a two channel SA, SA with tracking generator, SA with signal generator or two channel signal generator.? It will happen when I have the need for it!

Thinking of the TinySA itself and tracking generator, with two TinySA I think a very good result could be obtained if rather than using the LO from one to synchronise the second the PC software was used to offset the IF of the two devices, and the PC software kicked off each sweep in both devices to keep the synchronisation between the signal generator frequency and the analyser sweep.? I think it should be possible to keep the two devices in good enough synch throughout one sweep just by careful timing calculation (no of samples, delay duee to filter settling, some overhead and a margin for some timing error.? Then no additional hardware such as attenuators and amplifiers would be needed.

Worth a try anyway.? Gyula's version is getting very good results with the same SAW filters in each pair and an offset in the IF but still within the passband of the SAW filters.


73

Dave M0WID