Affichage des articles dont le libellé est DRUMULATOR. Afficher tous les articles
Affichage des articles dont le libellé est DRUMULATOR. Afficher tous les articles

jeudi 19 décembre 2024

Drumulator and Efinix FPGA.

A month after my last publication on the subject, a little progress...

And yes, I spent a lot of time on the EMU1 motherboard which, if it still doesn't work, gave me a lot of its secrets which will hopefully allow me to make it work again!

I am therefore resuming the implementation of the Drumulator in an FPGA. This time I test the small simulation board of the machine control panel.

In fact, I have a few issues that I didn't expect with this FPGA. Certainly, its cost is affordable compared to other offers on the market. But I discovered a pretty significant limitation of the implementation of these Efinix FPGAs.

In principle, it is of course possible to do the same thing as any other FPGA with the Efinix Trion range, except that...

It's not that simple. The internal resources are not as flexible as what you can find on other components, which means you have to rethink your way of doing things somewhat..

Basically, asynchronism is not the strong point of these circuits. Well, you will tell me that when we do FPGA, it is not to do asynchronous. Yes... or no. Actually it depends...

Well with the Trion range, the question does not arise : it's 'nyet, tovarishch' !

Once it is well integrated, you just have to review the design. And to validate my 'new' approach, I simply coded a basic Z80 system, accompanied by a very small program allowing me to test the display of the front panel of the Drumulator :


Which allows me to validate not only my way of doing things synchronously now, but also the functioning of the display system.

I can now get back to studying the CTC equipping the Drumulator and conductor of the entire machine.

The next goal is to obtain the same display directly from the Drumulator environment, that is to say with not only the CTC programmed in VHDL, but also the entire generation and reading of the interrupt vector, as well as than his acquittal. I admit that this whole vectorized IRQ system of the Z80 is still a 'happy mess' ;-)

I have (unfortunately) been working again for a few months in national education. Which leaves me less time to do electronics. I still hope to be able to make significant progress on the subject in the coming weeks...

mardi 19 novembre 2024

Drumulator and Efinix FPGA.

I'm busy trying to get the EMU1 working again, but I finally received the test control panel. I will finally be able to start testing the implementation of the CTC component inside the FPGA :


Obviously, the final panel won't look quite like this. It will also depend on the type of switchs that I can find for triggering the sounds.

Maybe a newly recreated switchs like these :


lundi 7 octobre 2024

Drumulator and Efinix FPGA.

The fact is that I have made good progress on the transcription of the Drumulator into an FPGA.

But what craftsmanship job is the management of vectorized interruptions on the Z80! It 'smells' like the thing put in place last, with the resources still available for the circuit, and added on top of the logic of the processor itself! 

Well, that's the effect it has on me. So, it's a bit complicated to create a circuit that responds to this mechanism, especially the CTC circuit, very important in the Drumulator. I still got there.

But another problem arises. I wanted to recover the values ​​of the display digits in registers in order to be able to exploit them as I wanted, but using the small resources of the FPGA development board, I absolutely cannot get an idea of ​​how the multiplexing of the display is set up.

Obviously, everyone knows the principle of multiplexing, and basically, it works in the standard way on the Drumulator, but I retrieve multiple information in the registers. So, and as I have already set up the display of the Dumulator on an FPGA board equipped with 7-segment displays, I decided to create a small display/keyboard card functioning in the same way as the hardware implemented on the Drumulator. And in any case this card will allow me to work more easily with the Efinix FPGA board because it only has 8 user LEDs in total: it's really too few and it's a real criticism that the 'we can do with this board.

Here is what I sent to be done:


Although the Drumulator display only has 4 digits, I implemented 8, which will allow me to also display other debugging information if necessary.

So I'm putting this topic in standby until I receive the printed circuit  board and can mount and test this display/keyboard card.


vendredi 12 juillet 2024

Trion FPGAs

And meanwhile...
I am testing new FPGAs, in this case the TRION family from Efinix.

Why venture into other FPGAs, when I have already worked with those from Altera (now Intel) and those from GoWin? Mainly for a question of cost and availability of 'small' footprints.

I really started testing the development chain only a few days ago and I must say that I am progressing quickly and easily. I had already studied the entire processor part of the Drumulator drum machine a few years ago. I implemented this part in Altera FPGAs, then GoWin in 2020, but I stopped this subject because of the shortage of components, then subsequently, the very significant increase in component prices, particularly that of FPGAs GoWin, which more than doubled.

And then, I recently discovered FPGAs from the Efinix brand and in particular the Trion family of FPGAs. Given the price of these circuits, I decided to resume studying the Drumulator. For this, I acquired a basic development board :


After installing the Efinity development software, I set about transcribing my VHDL source code to this new development tool. Its handling is not at all complicated and resembles the development software of other FPGA manufacturers, although simpler.


Although all windows can be floating, when you have a screen of sufficient size, the most practical thing is to have them all in the same window. The window 'modality' system used by Efinix can sometimes be quite annoying.

Nothing special for those who have a little mastery of VHDL, a language that I use mainly for writing code. The development board only contains a minimalist 'user' interface. A few LEDs and a few switches and that's it. It has no displays at all. So, it becomes a little complicated to test my Drumulator source. So I coded a driver allowing it to be sent to a serial interface, what the Drumulator should normally display on its four digits.

After some trial and error with the Efinity development software, I ended up obtaining a complete compilation of my source. All that remained was to test it on the development board.

But before that, you must install the USB drivers allowing programming of the FPGA. In fact, it is necessary to use the Zadig configurator in order to configure the two interfaces offered by the development board. The SPI interface and the JTAG interface.



'As they say', there is no reason why the installation of USB drivers should not work. And, normally, we must actually get the two drivers installed in the system.


At this stage, all that remains is to program the board with the generated code. For my first tests, I use JTAG programming, which allows the FPGA configuration memory to be directly programmed without touching the SPI interface and therefore without modifying the external configuration EEPROM. This allows you to find the demo code present when the board was delivered and therefore to check that it still works. We never know...



And there you have it, the whole procedure went well. Firstly, as I did not connect anything to the development board, I simply activated part of the LEDs with the memory zone selection signals, as well as creating, but externally to the Drumulator system, a low frequency blink clock for an LED. This will allow me to verify that at least the entire development.programming chain is functional, the traditional Hello World, in a way.




I developed a small expansion for the development board. The idea is to be able to test digital audio using boards recovered from an Akai digital recorder, as well as to test an HDMI type video output. These two topics are based on LVDS transmitters/receivers.

Otherwise, we can clearly see that the 'left' LEDs are lit. In fact, if you look closely, you can see that the one on the far left is slightly less bright than the others. This suits me well, this LED corresponds to access to the ROM of the Drumulator. It is therefore the most frequent access, which therefore represents a more intermittent ignition time, and therefore lower brightness.

And, what can't be seen in the picture, the LED on the far right is blinking slowly, indicating that the entire development chain is working.

Provisional conclusion: I am now sure that the entire development chain works, as well as the programming system of the development board. I also have strong presumptions about the functioning of the Drumulator core in this FPGA. I still have to connect a USB/serial adapter to my computer to check that I am receiving something when the board starts up.

I haven't coded the conversion of Drumulator segment type data to its ASCII character equivalent, so if it works, I will potentially receive anything, maybe even non-printable characters. It doesn't matter for the moment, the goal is already to see communication. And then it will be quite difficult to display anything else, given that I have not yet connected any switches to the heart of the  'Drumulator', I will not be able to generate any other information transmission. But hey, everything in its time...

lundi 1 juillet 2024

Just for fun?

It's been two to three years since I fully understood the 'democratic' operating (or dysfunctional) system of France. I know for example that, given my social class of origin which is totally foreign to the French bourgeoisie, and the way in which the oligarchy (the upper French bourgeois classes in power) has made the creation and exploitation of a viable business in France totally impossible for people not from the bourgeoisie, I know that it is totally impossible for me to 'succeed' professionally both as an employee and as an independent. This situation, absurd if we consider the collective aspect, leads to the economic results of France today as well as the result in the 2024 municipal elections in favor of the National Rally.

For decades I had felt that something was wrong in this country, but hey, to understand, you have to 'politicize' yourself. Which was not the case for me until recently.

Brief! However, it has been a very long time since I realized that what I was asked to do, within the framework of a job, did not correspond at all, neither to my real skills, nor to my desires. Reasons why I have always developed electronic projects privately. Lately I have even tried to insert myself into topics trying to promote my achievements and possibly market them. In vain. On this subject, however, I haven't really managed to understand yet. I have an idea, but I'm not sure.

By developing small electronic systems, I acquired some small skills. I am therefore going to implement them in what was my childhood dream: creating electronic devices dedicated to music. I have in stock an 8-way CV/GATE interface to be finished, as well as a MIDI connection system a little more adequate than the current MIDI network to be finished. So I'm going to devote myself to it.

And, since I have just repaired a Drumulator again, I like this machine and I have already prototyped pieces of it, I will start by trying to create a complete clone. I will put the progress of the project on this post.

Why the Drumulator?

My last repair dated 2024/06/30

Because it is a rather particular machine which, despite the theoretical simplicity of its operation, produces very good percussion sounds. This is because the sound production system is based on playing non-linear 8-bit samples. To simplify, it uses a particular coding that was used in analog telephone networks to artificially increase the audio quality of communications. Its 8-bit resolution thus increases to a 12-bit equivalent. Obviously, as the conversion cannot be linear, this gives a very 'punchy' but nevertheless very well defined rendering, perfect for percussive sounds.

Clone this machine, yes, but in a hardware way or in a software way?

In fact, I have already had the opportunity to develop the processor core of this machine in FPGA, as well as the wave sequencer. I did this on an Altera FPGA, then GoWin. I wanted to use Gowin FPGAs, but between the time I carried out my first tests and when I could have started producing a prototype, the price of Gowin FPGAs was multiplied by three!

At that time, about four five ago (2019), the price of a used, working Drumulator was around €250 in France. Which did not leave much room for the creation of a profitable machine from a financial point of view. The price of a Drumulator has now increased significantly, and is around  €700 ~ €800, leaving room for a clone.

https://fr.audiofanzine.com/bar/e-mu/Drumulator/

I also spotted FPGAs from another manufacturer whose characteristics are quite interesting and whose selling price corresponds to the development of equipment that must be sold at a reasonable price: the Trion family from Efinix


Obviously, moving from one FPGA family to another is not particularly trivial. Not because it involves changing the type of technology, but rather because it is 'yet' a leap into the unknown. When you 'habit' with a component, you navigate within your 'comfort zone'. Obviously, changing manufacturer means changing development software, physical constraints on the component itself, etc... We never do it lightly. But hey, at some point you have to go.

If I start this topic about an FPGA Drumulator, it's because I have already carried out some tests with the Efinity development software, from Efinix. And I know I can compile a complete Z80 system inside a Trion Fpga component.

But as of now, I have never actually programmed the study board I purchased.



For the moment, I have just implemented a Z80 core associated with the original Drumulator ROM in version 3.0. I have no means of display or input. I will therefore ensure that the message which should normally be displayed on the four digits of the Drumulator is displayed on my PC screen. To do this, I will just need to implement a system that translates the codes sent to the digit into a character string suitable for display on a terminal.

I will keep this principle subsequently, because I intend to dedicate the management of the front of the machine to a processor which will be connected by serial port to the FPGA.

So: attempt to activate the core of the Drumulator with display on the serial terminal of the 'famous' message "Bad"!

lundi 6 mai 2024

A new Drumulator in the workshop.

This time, it is the machine of a French musical group which made itself known in the early 80s. History does not say whether or not this machine was part of the first successes of this group. Good question, by the way...

I have to admit that of all the Drumulators I have worked on, this one is in the best cosmetic condition. Almost perfect.

Let's go for the identity of the machine:


With the owner's tour of the exterior done, the big question: what about the interior? Because I was given to seeing dramatic things, of the true-false geek type who tried to add sound ROMs but who above all succeeded in crashing the machine by adding an incredible number of wires and modifications to the motherboard etc, which took me hours to remove!

In addition I have doubts about this Drumulator: result of tests or naval battle?


But no, there too, a nice surprise inside. No catastrophe in sight, at least other than a breakdown due to the machine itself and not as a result of outrageous tinkering.


We see very clearly that the machine has been updated with version 3 of the firmware for MIDI management. A MIDI input adapter card has been added as required, and placed/glued correctly. 

It is even possible to say that the original ROM was removed with a screwdriver since we can clearly see the surface condition of the first resistor above the ROM whose coating was burst with the place which served as a support for the screwdriver.

The battery has never been changed. Luckily, it didn't sink. I checked her, she's dead. As a result, sequence saving should no longer have been working for a long time. I imagine it is mainly used in MIDI.


You will have to remove it anyway and place a standard 20CR32 support somewhere on the case.

Little check, at least the voltage selector is correctly positioned on 230V:


Small observation, the motherboard also has an identification number. It is not the same as that of the machine :


The usual checks having been carried out, what is the problem with this machine? At first glance, it seems simple since the machine does not turn on at all.

Power problem or CPU boot problem? Again the first observations are simple, the motherboard does not have any DC voltage. Neither on the analog part, nor on the digital part.

We go back to the source: no sign of alternating voltage either at the two secondaries of the transformer. Hmm... We're getting closer!

The mains voltage nevertheless arrives at the primary of the transformer. No sign of heat or burnt, it does not seem that the machine was connected to 110V.

All that remains is to test the primary windings which are, at 230V, connected in series. The observation is clear, one of the two primaries is cut. The transformer is therefore inoperative.

This is very strange. Transformer connections appear good. No burnt rifle, no burnt marks, no hot smell. What could have been the cause of this breakdown? A manufacturing defect in the transformer?

Now knowing this machine quite well, to further investigate I will connect the digital part of this Drumulator directly to the 5V of a protected laboratory power supply. Even if the processor does not start, this will allow me to check the approximately real 'digital' consumption of the board.

A few days later:


After connecting a direct current power supply directly to the two terminals of the diode bridge of the 5V part: 1.2A at 6V at the output of the power supply, although programmed for 10V, and 0V at the output of the large 5V regulator placed on the 
metal part of the case:



Simple conclusion: regulator dead. I forgot to specify, but according to tests carried out on different Drumulators, in normal operation, that is to say with the displays on, the average consumption of the digital part of a Drumulator is around 1.2A. So, with the regulator in the regulation loop, I already have the 1.2A consumed and 0V in power on the logic circuits.

But at this stage, I still have to confirm that it is indeed the 5V regulator that is dead. So this time I connected the DC power supply set this time to 5V, directly in place of the Drumulator regulator output. To do this, I cut the three wires connecting the 5V regulator to the motherboard.

And this time, I have consumed 1.2A but with the logic circuits supplied at 5V. Confirmation therefore that the 5V regulator of the Drumulator is indeed dead. But, obviously, the machine does not start.

The design problem of this machine remains for me the detection of power supply operation. EMU has implemented a complex system to ensure that the machine's three power supplies are present in order to authorize the microprocessor to exit RESET. This doesn't do much except make testing the operation of the machine much more difficult. For example, it is impossible to test the digital part if the analog part is not powered. The best thing to do is to remove the power supply monitoring circuit and directly shunt the validation outputs to the desired potential.


All the transistors in this section are used to test the validity of the machine's three power supplies, and also to generate the processor RESET signal. RESET signal that this system generates poorly, which deteriorates over time, and which ends up no longer working at all. This is obviously also the case on this machine.

And I'm not talking about the different power supplies generated in all directions, which must be provided as best as possible during the test phase in order to put the digital part in 'potential' starting condition.

Brief! Having spent some time making the necessary modifications just to get this machine into potential boot condition, I ended up getting my favorite message on the displays:



At this point, I can only confirm that the 'computer' part of the machine is working. I don't know anything yet about the waveform sequencer part, nor about the analog output.

The only thing I can do right away is to change the faulty digit:



I seem to have one or two displays of this type in stock.

I will now pause troubleshooting this machine. To continue in better conditions, I need to redo the power supply, starting by finding a compatible transformer, i.e. with two output voltages available, as well as replacing the original 5V regulator with a switching model, more reliable and dissipating much less heat :


I have made this type of modification on several machines with very good operating results.

Updated 06/05/2024

I finally received the transformer necessary to put the machine back into service. 



It is not very easy to find a transformer with the necessary number of windings for this type of application. During my previous modification of this type, I found a transformer with a lower voltage for manufacturing the +5V. Luckily I use a switching regulator now to generate this voltage needed for all the digital part of the electronics.

And, consequently, I removed the linear regulator fixed on the metal frame of the Drumulator, acting as a thermal radiator for the evacuation of the heat emitted wastedly by this original regulator.


I removed also the original transformer which had one of the defective secondary windings.

And, before placing the new transformer, look for the direction of the windings. Indeed, for the analog part, I must put the two windings in series, the midpoint therefore making it possible to create the reference of a symmetrical power supply, while for the digital part, I must put the two windings in parallel in order to benefit from of greater power with the base voltage of a winding.

The problem with this transformer is that the magnetic direction is absolutely not indicated. Each winding has wires of the same color. It is therefore necessary to carry out the tests 'brutally' while still protecting yourself from magnetic short circuits. The use of a very low power bulb allows it to act as an 'automatic' fuse.


It is also important to wire the primary of the transformer in the correct way. Everything goes through a single connector on the Drumulator. This was not the best way to do it in my opinion. Besides, this would no longer be authorized today. It is therefore necessary to find the way in which the primary windings are connected according to the voltage selector.

Art?
Unfortunately, it will not be possible to wire the windings of the new transformer in the same way. In fact, it does not have two separate primary windings but only one primary winding with a central tap for 110V. You will need to configure the wiring for a 230V connection. This will not pose a problem given that the machine is and will most certainly remain in France.

Obviously, the large power connector doesn't like to be handled too much. Some of the wire strands were pinched too hard when crimping them into the terminals. With corrosion attacking the materials, it becomes brittle and, inevitably, ends up breaking at the connector pin. The only way to remove the pin to re-solder the wire is to push on it using a medium-hot soldering iron so that the plastic melts enough to allow its extraction.

This allows you to do a much cleaner job than trying to solder the wire with the lug in place. I have seen interventions of this type that are really not clean.


In the end, it's done well, but it takes a lot of time...

Once this connector was repaired, I was able to start installing the new transformer. Fixing it does not pose any particular problem, except that you will still have to cut the stem of the screws, which are too long.

Rewiring the transformer does not pose any particular problem either, except for the attention and the test before powering up, because in the event of a big problem, it would be possible to damage the electronics of the machine . This is the critical and risky point of the entire operation of putting this Drumulator back into service.



After an hour of rewiring, I will be able to plug the new transformer onto the Drumulator motherboard. This will not pose a problem for the generation of +5V given that I have not yet equipped the machine with the necessary switching regulator, on the other hand it is quite different for the symmetrical analog power supply. You will have to carefully check that there is no wiring error because all the components of the analog part are in place. An error could have serious consequences on the components.



Updated 06/12/2024

No 'magic smoke' when reconnecting the transformer to the electronic board of this Drumulator. All regulated voltages are present. However, I have to resolve a small problem due to changing the transformer. This concerns displays and LEDs. Normally these elements are powered by the rectified but unregulated voltage supplied by the transformer. However, having not managed to get my hands on a transformer providing the same output voltages, I am now with not around ten volts but a little over fifteen volts. It's still a little too high.

So I placed a 10V regulator in the power line of these elements.



In order to finalize the operational check of the machine, now that all the voltages are present, and especially to test the sound generation and therefore the entire waveform sequencer part, as well as the analog part, I replaced all the components that I had removed during my first tests, as well as the temporary electrical connections.

And there, a pleasant surprise. I can hear the drum sounds coming out correctly through the line jack. A priori I don't encounter any problem except one of the other displays which lost a segment. It's really strange, this is the second display in this situation. I still have my last available display. I just have to replace it.

I will also try to place a small radiator under the new 10V regulator as well as on the regulators of the analog part. The voltages supplied by the transformer being slightly higher than the original ones, the linear regulators heat up a little more.

The repair of this machine is now almost complete!

Updated 06/15/2024

After testing all the keys and functions of the machine, one of the sound trigger buttons remains that does not work. It's easy to repair. On the other hand, the linear potentiometer does not respond at all. I therefore cannot adjust the volume of the instruments, and those which have the volume at zero are therefore not available.

The cause of the problem was not difficult to find :



The problem is quite simple to determine. I had never seen this kind of problem in a potentiometer of this type, but I learned that the machine was 'violated' at a certain period of its life. This potentially explains this!

So I put this part of the slider back in place, adjusting it as best as possible. This operation is not that easy to carry out because when you apply the hot tip of the soldering iron to melt the plastic of the cursor, the metal blade finds itself 'swimming' in a rather viscous liquid, which makes positioning difficult. But : 



The result looks good!

After this operation and reassembly of the potentiometer in place in the machine, I was finally able to listen to all the basic sounds of the Drumulator. No distortion, the sounds are all very good.

I still have to resolve the RESET problem and the restoration will be complete. Afterwards, I will carry out some cosmetic operations and that will be the end of the return to life of this Drumulator.

Small update...

In fact, I just understood why the RESET circuit as it was implemented in the Drumulator is completely, hum...  'stupid'?

Until now, I 'just' applied a correction suggested by EMU to 'improve' the RESET. But I still had difficulty implementing this solution. The value of the capacitor must be tested each time. And it took so long that at the time I even completely recreated the RESET system.

I no longer have this system, I used all the prototypes I had made. So, as I stared blankly at the page concerning all the power supply in the electrical diagram of the machine, the 'thing' appeared to me in all its 'glory'!

I fixed the problem in a few minutes by placing a few components in the right places. Not only does it work, but it will continue to work, in fact, all the time now. Okay, I'll keep the solution to myself. It's like mushroom corners, we avoid revealing their location ;-)

well well well... All I have to do now is to place a 20CR32 battery holder for the RAM backup as well as a solution to evacuate the heat from the voltage regulator that I added.

Updated 06/19/2024

Obviously, this never happens as planned, especially on a very old machine that has had a fairly eventful life.

RESET of the machine is now actually carried out seemingly. On the other hand, saving RAM posed problems. In idea, the whole system of controlling the voltage, generating the RESET and protecting the saved RAM is well thought out, but it only takes one small detail that goes wrong and the whole system collapses.

And this is the case when the components start to age. And no, even by replacing the head capacitor in the 5V line, the system does not work again! But, again, I ended up finding the right way to ensure that the RAM saves correctly without corruption at startup. And no more 'Bad' message when restarting the machine.

OK, so the machine is finally fixed? Well no...!!!
Three sounds do not come out, they are the TOMs!

In fact, these are 'just' two ways that don't work. The TOMS HI and MID share the same sound generation channel.

And it's back to debugging. But this time, I'm moving directly towards the analog part, since it seems to me that the digital part of the sound generation works very well.



After some time searching, I actually found a problematic component. This is a quadruple TL084 which has a defective AOP. For the moment I have not investigated further, but I thought I had solved the problem of the two faulty channels, but in fact no, only the channel concerning the TOM LOW has become active again. 

I still have to find the reason why the TOMs Hi & Mid are not working...

Updated 06/25/2024

This time it's good! 

The machine outputs all the sounds well. It always starts correctly every time, and I haven't had a saved memory problem ('Bad' message at startup) since I fixed it.

So I had to replace two components. A quadruple AOP circuit of which two AOPs were dead out of the four. But that wasn't enough, one of the two analog output filters (SSM2044) was also dead.

The AOP, TL084 circuit is easy to replace. On the other hand, obviously, we no longer find SSM2044. Fortunately, there is a new version that works very well. It comes in CMS format, so this circuit must be placed on a DIP adapter. 

Once these two components have been replaced, all sounds come out of the machine correctly. The new analog filter works as well as the original one.

The defective SSM2044:



And the Drumulator board equipped with the two new integrated circuits:



All I have to do now is find a small metal blade to solder on the 10V regulator that I added, and also clean three switches which are really not pleasant to use because the contacts must be so dirty...

Thus ends the adventure of restoring this Drumulator. Nothing too complicated, but there are a whole series of small repairs, or adaptations to be made. All of these operations obviously take time. But the result is there!

And, icing on the cake, you can hear THIS Drumulator in this video:


In true 80s style : enjoy!

Updated 06/25/2024

Back to home :



Well surrounded by a TR505, a TR707 and two Mirages... 👍

And thank you to Philippe for his communicative passion!

mercredi 8 juin 2022

Drumulator Clone...

That's it, I've pretty much placed all of my ideas regarding my recreation of the Drumulator. I obviously added some goodies compared to the original machine.

Now I have all these components to place on a PCB:

Hmm, that's not my favorite part of the job...

[06/09] After a few hours of work, here is the general idea of ​​the front panel:


You will have understood, it's new, but old style version, because... I like that too.

[06/15] There's always a moment when you wonder if you're going to make it!


Anyway, I continue to place the components. It only remains for me to place those dedicated to the 'simple' output filters and as well as those dedicated to the commands/display of the machine :


Like that, it seems clear and well arranged, but what will be the routing with all these signals!!!

[06/16] After a few more hours of work, it becomes clearer...


3D visualization, even if it is not perfect, still allows you to get a fairly close idea of ​​what the printed circuit board will look like:


All you have to do is try to route all the connections. It might be 'sporty'!