FeelTech FY6900 Web based software

[katzenjens]

Hi,

some 4 to5 years ago I obtained a FY6900 from Amazon. Works ok, after the dodgy power supply was fixed and a socket for an external 10 MHz input has been installed. My problem was, the software is buggy and frequency input was limited. My firmware version is 1.3 and I don't like to update it, since there are different hardware revisions.

So I did some reverse engineering, used wireshark and a terminal to dig out as many commands as possible. It took me a week, but now the project is sucessfully finished. It uses any Chrome based web browser as a front end. No other software required exept CH340 drivers for USB to serial.

You can get all the info plus the web page from my github here: https://github.com/katzenjens/fy6900commander
Please give it a try. The web page itself runs locally. Either you use the link inside the Info or host the page on your own web server.

It would be great, if anyone, who uses the FY6900 or even FY6800 or similar devices around, tries out this web based software. Since there are different hardware and software revisions around, there will be issues, mainly with frequency tuning. I need some input, if there are differences. Because the latest original software (7.15) does not work for me. So, feel free and send me issues, if anything does not work properly. I would like to make this software as compatible as possible.

It may help, if you include the in and outputs via the debug terminal.

Realization by me, "dirty work" like UI and some javascript was done by Gemini, but on a short leash. 😁 Not really vibe coding.

Thanks,
Jens

[BillyO]

Hmmm, I almost wish I had one of these to try this out.

Cool

[Aldo22]

So I did some reverse engineering, used wireshark and a terminal to dig out as many commands as possible.

There is a “FY6900 Serial Communication Protocol”.
Didn't you have that?

[katzenjens]

Yes, there is, but it is incomplete.
Update... No, it is not.
Thanks. I might update the project.

[marco58]

Thank you Jens for sharing your work!

It would be great, if anyone, who uses the FY6900 or even FY6800 or similar devices around, tries out this web based software. Since there are different hardware and software revisions around, there will be issues, mainly with frequency tuning. I need some input, if there are differences. Because the latest original software (7.15) does not work for me. So, feel free and send me issues, if anything does not work properly. I would like to make this software as compatible as possible.

I started testing your SW with my FY6900 firmware version 1.8.
I found these issues:

as expected written frequency values to AWG are wrong (but read values are correct!) due to different frequency unit
FW V1.8 uses Hz: "123456.123456" max 6 + 6 digits, leading and trailing zeroes may be omitted 

V1.8 has two new waveforms (4-Pulse and 8-Pulse), so waveform index is different (ok up to "Chirp" included)
and now with your SW we have:
4-Pulse instead of ARB1
8-Pulse instead of ARB2
ARB1    instead of ARB3
(and so on...)
ARB62   instead of ARB64
(so ARB63 and 64 are not settable)

ARB loading is ok, but with 2 position offset

I'll go on with testing...
ciao
marco

[katzenjens]

Hi Marco,

thanks for testing!
Can you please "play" a bit with the frequency in- and output inside the debug window?
In my Version (1.3) it is 6 digits left and right of dot for read (RMF)  60000000.000000 and 14 digits for write (WMF060000000000000) with 60MHz
So I think, sending WMF060000000.000000 to your unit for 60MHz should be correct. Please give it a try and tell me your findings. I will include this in the next update. Since there are versions with 100 MHz around, we might need the trailing zero.

Regarding the Arb Waveforms, I am not sure if I want to include this, since I have to rewrite the unit. 🥴

Thanks for your support,
Jens

[marco58]

Hi Jens,
here is my tests (empty lines added for clarity):

[21:22:29] TX > WMF059000000.000000
[21:22:55] TX > RMF
[21:22:55] RX < 59000000.000000

[21:23:55] TX > WMF059000001
[21:26:45] TX > RMF
[21:26:45] RX < 59000001.000000

[21:27:29] TX > WMF060000000.000000
[21:27:36] TX > RMF
[21:27:36] RX < 60000000.000000

[21:28:07] TX > WMF059000000.000001
[21:28:17] TX > RMF
[21:28:17] RX < 59000000.000001

[21:29:04] TX > WMF0.000001
[21:29:10] TX > RMF
[21:29:10] RX < 00000000.000001

[21:30:05] TX > WMF060000000
[21:30:15] TX > RMF
[21:30:15] RX < 60000000.000000

All settings were executed correctly!
Version 1.8 is 6 digits left and right of dot for read (RMF) and 6 digits left and right of dot for write (WMF), too.

marco

[katzenjens]

Thanks Marco,

I will include this in the next version. Apart from Frequency and ARB waveforms, everything else works?
Mainly Voltage adjustment and sweep frequencies?

Regards,
Jens

[marco58]

You are welcome Jens! You made the hard work...

Let me some days and I'll continue testing

[Faeren]

Tangentially related, but is the FY6900 still a good go-to nowadays? Need a signal generator for working through AoE and making circuits to poke at.

[katzenjens]

It works fairly well for that price. There are better function generators around, but they cost a lot more. Used mine on and off for years. I  heard of users, who got the output stages fried.

Jens

[katzenjens]

Hi Marco,

can you give this version a try?
https://katzenjens.github.io/fy6900commander/new_version.html

This should work with your hardware. I also included sync options for Ch. A and B in the system tab.
I have not touched the waveform area, because this would be not worth the effort. Much potential to destroy stuff. 🤣 And I have not included the frequency counter because polling would be far too risky in javascript. 😬

Hope this will be the final version. So even the old FY6800 is covered with this. Will update the github repo later.

Jens

[marco58]

Hi Jens,

I tested your new version, CH1 and CH2 frequency setup is now ok, but there are issues with modulation.
(anyway Modulation Center is a very useful solution: saves a lot of buttons pressing / knob rotating!)

MODULATION CENTER
FM
SOURCE CH2
Deviation/HOP = 1 Hz

Commander sends:
[18:19:05] TX > WFM00000001000000
and my AWG frequency deviation becames 1 MHz
("BIAS:01'000.000'000'000KHz" displayed on its GUI)

I made some tests for verification:
"WFM1" or "WFM0000001" set 1 Hz
"WFM123.456" set 123.456 Hz (6 decimals are also accepted)
So there is the same 10E6 factor correction as with WMF command

FSK
Deviation/HOP frequency setup is not functional, with my AWG needed commands are (Commander sends WFM):

WFK: Set the second frequency of FSK modulation
WFK123.4 indicates that the second frequency of setting FSK modulation is 123.4Hz.

RFK: Read the second frequency of FSK modulation
123.4 indicates that the second frequency of the set FSK modulation is 123.4Hz.

sync options for Ch. A and B are ok

last minute found (not investigated now  )
SWEEP/VCO
there is an issue with offset: values on AWG have a -12V offset

thanks, ciao
marco
 

[katzenjens]

Thanks Marco,

deviation setting will be easy. FSK is my bad, missed a page of my own notes. 😬
Issue with offset, I have to dig deeper. Give me some time.

Update! New code is online: FY6900 New Version here:  https://katzenjens.github.io/fy6900commander/new_version.html
FY6900 Old Version: https://katzenjens.github.io/fy6900commander

Everything should work now. FSK Hop has its own field. Frequency input instead of deviation. Took me some time to realize. 🙄
So, frequency input for FM deviation and FSK HOP are hopefully aligned to the old and new version.

Sweep voltage offset is fixed as well. I simply added 12 to the logic.

Please give it a test. As I heavily cleaned up the code as well, there might be some unseen bugs. But I have not found anything yet.

Jens

[marco58]

Hi Jens,

I tested last version and only a issue, for a probably little used function, is found:

in VCO mode, Commander never sends Linear / Log commands (SMO0 and SMO1), even if Scaling mode is changed, "SET VALUES" button changes color and it is then pressed (and changes color again)

if I manual send these commands with debug command line they are correctly executed

Note: I decided to install Chromium just for your application (I use Firefox) and it was a good decision... I like Commander a lot!

Thanks
marco

[katzenjens]

Hi Marco,

yes, although I have the FY6900 for ages, I hardly used it because of the awful interface and buggy software. But now, it makes fun playing with it and fixing old radios, measuring amps, speakers and so on. I'm thinking of including macros for frequently used functions with save and load functions. Especially useful for Modulation and Sweep functions. But can't promise anything yet. To me, Javascript always has been a nuisance. This is the first project which makes sense. 😁

Yes, I found that some of the variables are not saved properly which is irrelevant for use it but would be a nice-to-have. Unfortunally, the unit itself does not save all of the settings. I will look, what I can do. Watch this space...

[Edit] With VCO, Log/Linear does not apply because this is controlled by the VCO itself. But I found out, Log/Lin does not work anyway. 😱 Not even with Ch2 as source. Sending it to the unit works, even the display shows it. But when I tried it with an audible sweep, there was no difference. Bummer! 🙄

By the way, I have a similar project for the BG7TBL WB-SG1 Signal Generator on my Github.

Regards and thanks for optimizing the project. 👍

Jens

[unseenninja]

Great project! I have an FY6900, plus the 8300S model with three channels.
When I get some time, I'll test both.

I'm sure there are some commands which are common between the models.

[katzenjens]

Hi,

unfortunally, the FY8300 has a different command set. And as there are errors in the original command set of the FY6900 I suspect, the command set in the link below is slightly dogdy as well.
https://de.scribd.com/document/721702697/FY8300-Series-Function-Generator-Protocol-Specification

But you could fork my project on github and modify the commands and values. That's one reason why I cleaned up the code.

Regards,
Jens

[MathWizard]

How hard and expensive is it to make a DIY version like these lower end signal gen's ? Are there github versions, with all the opensource code ? I have a 120MHz AWG, but it would be nice to have another 1-2 cheap signal gen's, besides just some 555 circuit I might slap together.

I have a soundcard to play with too, there's a few projects with those that interest me.

[katzenjens]

Slightly offtopic in this thread, but take a look here: https://www.instructables.com/Arbitrary-Wave-Generator-With-the-Raspberry-Pi-Pic/

You will find something like that when you search the entire forum with the keywords.

Regards,
Jens

[smk]

Hi Jens,

thanks for your SW. I recently bought a panel mount FeelElec FY3900-10, it came without manual and software. I only tested some parts of your SW and up to now ownly found two points that I had to modify in my local copy.
The Hardware Offset Shift is 10V for the FY3900 and it does not accept KEY17 as a command. I use SBE1 to start the sweep and simply press the Set Value button to stop the sweep.

The Lin Sweep looks ok but I think FeelElec messed up the Log Sweep completely.
In "Forth" direction the frequeny should rise exponentially to get a straight line when using a Log scale for the frequency. But instead of first rising slowly and then faster it starts rising fast.
In "Back" direction it looks a bit better in the first half of the sweep but the slope is too small.

Using the same sweep settings with my Siglent SDG2042x I get the expected results, symmetic for Up and Down direction.

[katzenjens]

Hi smk,

which version did you use? The "index.html" or the other one? I would like to add the info to the readme. Great that the FY3900 is supported as well. Have you tried "KEY0" to "KEY20" via the debug terminal. You might find the right key. The log sweep is buggy with the FY6900 as well. You may use FM modulation with the appropiate waveform on Ch.B as a workaround.

Jens

[smk]

Hi Jens,

I used the new_version.
I will test the other KEYx commands when I am back from work.
Perhaps I will also install  Firefox 151.0beta to test it with your SW.

Stefan