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[Sokol1]

Samples of SVMapper use - in IL-2 Sturmovik:



Button 1 and 2: ON-OFF (toggle) switch, button 3 push (momentary) button.

So, you have a visual feedback of landing gear position, and a "automated" LG in F4F and i16. TS PTT button open mic while pushed.

Notice that SVMapper alow to use multiples profiles using "Profile on press" and "Profile on release" functions.

And about Mjoy16 layout: is convenient change the axis signal inputs pins for this sequence:
Signal
Gnd
+5V

If any axis is unused, put a jumper over Signal + Gnd pins to minimize "spikes" in these axis.

With original sequence:
Signal
+5V
Gnd

Is difficult to put jumpers to ground these axis and alow marge for mistake (signal and +5V).

Sokol1

[Frakk]

The SVMapper looks great. About the analog inputs, when I started to redo the original board for the controller(pg5 I think) tronicgr suggested to use this layout. He said " I think a AMC1.5 feedback pot like pinout: (S + -), is easier to design on pcb near the Atmega16 chip and more immune to noise!"

As far as I'm concerned it doesn't matter in terms of pcb design. When we don't use them, we don't really care about where those axis are (the last used pin will controll the rest). I agree it would be a good practice to do it as you suggested and I'm open for any changes and other's opinion.

[Sokol1]

Frakk,

Me observations about analog inputs pins is based in pratical use of Mjoy(8) and Mjoy16.
For some reason Mjoy is high sensitive to noise, so if you connect potentiometers in all axis imputs, and use shielded cabbles, all work fine.
But, if you leave some axis not connected to pot, HALL sensor... this axis start to "spike".

In AviaForum (http://www.sukhoi.ru) wheres Mindaugas (Mean Dog) start Mjoy project back in 2004, they recomend use jumpers (like ones used in motherboards) to ground unused axis, so if Signal are close to Gnd is more easy to do.
No other reasons to do this change.

Sokol1

[Frakk]

Thanks Sokol for your input and sharing your experiences! As I said, I agree it is a good practice to use the jumpers and I will post an updated layout once I'll have time. I wish there was an english translation of that forum

[Frakk]

Here is what I would say the first official version of the redesigned PCB. I made it so it would be easy to make at home with minimum trace width and copper distance of 0.8mm (except at the USB connector), even more where it was possible. I reduced the number of diodes to 12 to make it even simpler and included pads in addition for an INIT pushbutton. The pins for the analog inputs are also changed as Sokol suggested, now a jumper can simply disable them connecting to ground. The crystal capacitors and the inductor are placed inside the IC socket to save room and tight pads/traces.

The next step will be a separate controller and matrix board.

[gregers]

Check it out... it's in polish, but everything necessary is there

http://mjoy16.googlepages.com/plytka

[Frakk]

Thanks gregers, if you post that board about 2 months ago I may not have started to do this one. There is only one problem with the board you posted, and that is getting it made. For a 2 layer pcb with plated through holes and such tight traces between the pads, this board has to be orderd from a pcb manufacturing company. I designed this board specifically for those who want to make it at home with only what is necessary. It is only 1 layer, minimum copper width and distance is 0.8mm and reduced number of components, and it still only measures 13.5x8.5cm. I could add the additional 8 pulldown resistors without any significant change in the layout too, although that is not necessary because they are connected to ground internally when not "high" anyways.

[GeorgeBoles]

Dear Frakk (and Sokol if you are still watching),

I am just about to burn my board, so these questions will help determine my final alterations:

1. Do I need to worry about the resistors that Sokol describes? What do they do?
2. Looking at what you have said, Frakk: can we do with that smaller number of diodes? What advantage is there of having the 50+ diodes (one per switch) as compared with your scheme (one diode per digital "circuit")?

Using only 8 - 12 diodes would make re-wiring my joystick buttons much easier: to use wires in the joystick rather than diodes.

3. I have read that the diodes should be as close to the switches as possible. The lead from my joystick to the Mjoy was going to be 1.8m. Is this too long for your arrangement?

4. I think you could do the wiring with just 8 diodes, anode to each of PC0 - PC7. Is that an alternative to your arrangement - 12 diodes with cathode to PB0 to PB7 and PD4 - 7?

Thanks to you all for your input, and a special thanks to Sokol for his visit. Now all we need to do is have Mindaugas visit and everyone who is important will have been here!

Regards,
George.

[Frakk]

George:

1. As I posted before, I don't think they are necessary. The way TTL logic and the matrix key system works, the outputs from the column connections will be Low/0V/Gnd, except for a "scanning" High/5V/Vcc that goes from 1 to 8 over and over.

2. I do not beleive there is any advantage of having more diodes than 1/input (rows,12 diodes) or 1/output (columns, 8diodes).

3. Technically for our application it doesn't matter where you put the diodes. I strongly recommend using shielded twisted pair wires for all signal cables, such as the cat5 network cable connecting the shield wire to ground, if you haven't already done so. You can share Vcc and Gnd between analog inputs to reduce connector and wire size too, a 10pole shielded wire will take care of all 8 analog inputs.

4. Yes you could do the wiring with just 8 diodes, that is exactly why I wrote 8-12 diodes! The diodes have a 0.7V drop, anything below 0.7V will be absolutely blocked. Although I don't beleive the diodes are critical in the operation since the input High threshold of the IC is higher than that.

Please note that all my answers are based on my tests with the breadboarded circuit and my theoretical knowledge. I haven't noticed any ghosting or unnatural operation without any diodes or the 8 pulldown resistors, but that doesn't mean anything.

George, on your circuit I would make these connections easily changeable (diode and resistor placements) in case one works better than the other. It really takes only 5mins of soldering. I think everyone would thank you for trying out the different options and see what difference they make in real life operation. And if you posted pictures it would be even nicer!

[Sokol1]

Frakk,

These 8 resitors in pins 21-29 appeared in some revisions of PCB made by russian/poly users. Seemingly, without him begin to appear "ghost buttons" when used all of the possible buttons, ~120 include HAT.

Same case for one diode in each button. Probably, with an smaller number of buttons being used this had not happened.

But if your new scheme work whitout "ghost buttons" is very nice.
Plenty simplified the buttons connections.

GeorgeBoles,

If you objective is re-wire a old gameport stick to USB, I sugest that you make one these small PCBs whitout key matrix. In case has not made one.

Sample (~57x34mm): http://aviasimrus.spb.ru/forum/showthread.php?t=1014
This PCB requests capacitors with 2,54mm betwen terminal (pins).

Then you put PCB in the base of joystick and can use shorter/less cables.
In this case, put one diode in one terminal of each button/HAT, and wire according to the key matrix scheme.

The eletric circuit and .HEX (firmware) these small one is same used by Frakk, when Mindaugas leave the Mjoy project he liberated the Mjoy16 code for DIY use, but blocked it for edition, the only thing that can change in HEX is the name - with 4 letters - and the vendor ID.

PCB with key matrix is good to "button box" or cockpit, but complicated to use in joystick re-wire.

Sokol1