PRIMOVA - GKMX-33 Project - The ultimate-No US-20 bug 3in/3out GK switcher

Started by CodeSmart, March 25, 2014, 12:50:21 PM

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CodeSmart

The SY-300 is no show stopper.
I think I'll still be able to get rid of a handful GKMX-33 so proceeding as planned.  ;D
Today I've sent away and paid the production cost of the first round of printed circuit boards.
Five different types of boards, 5 pcs each.
But I got more gear than I need...and I like it!

mapperboy

Any thoughts on what you would need to charge to offer kits; i.e. boards + any ext components or boards + connectors + screened front panel or any combination for us DIY kit builders?  I love building but don't have a SMT assembly setup.
"No such thing as spare time.
No such thing as free time.
No such thing as down time.
All you got is life time. Go!"
- Henry Rollins

CodeSmart

Quote from: mapperboy on April 16, 2015, 08:25:22 AM
Any thoughts on what you would need to charge to offer kits; i.e. boards + any ext components or boards + connectors + screened front panel or any combination for us DIY kit builders?  I love building but don't have a SMT assembly setup.

The demand for kits has been little. We will see later. I got tons of work to do first.
Greetings from a hotel room in Pisa, Italy  :D
But I got more gear than I need...and I like it!


Dunny Daw

Quote from: CodeSmart on January 05, 2015, 11:16:42 AM
Have had some days off now and this is what seems possible to do:





Hello,

I've just seen this thread and haven't gone through it in detail, but it looks interesting to me.

But in the image above, it shows 12V power supply.  Could this be made 9V so it could be powered off one supply for a pedal board?

I've also been reading a lot of Elantric's posts about using a battery powerbank to power the pedal board, and that provides a 9V supply.  Would be great to only have to carry a single power supply around.

Kind regards

Elantric

QuoteI've also been reading a lot of Elantric's posts about using a battery powerbank to power the pedal board, and that provides a 9V supply.

FWIW - all the battery packs I mention in the Poweradd Battery thread

https://www.vguitarforums.com/smf/index.php?topic=10662.msg77071#msg77071

. . .  can be switched to provide 12VDC, and lately I'm using multiple battery packs,  as needed for lowest noise.



For example my Digitech Jam Man Solo XT Looper has noise and does not "play well" if I run it on the same battery pack as my whole pedal board

  - so I'm using a dedicated battery pack just for the  Jam Man Solo XT



they are cheap on Amazon


Remember the GK 13 pin gear all runs on bi-polar supplies ( +7VDC & -7VDC).

Its rather straight forward to dedicated one Battery pack to supply 12VDC for the  GKMX-33

CodeSmart

Prototype boards on their way from manufacturing in Asia abt.,$100. And just ordered components for abt. $300 from Germany and UK to populate them. Dangerouse game this is. I hope I'll manage to get 'em running  ::) If not... I'm toasted.

And Elantric is right, need 12V to produce +/- 7V inside the unit.
But I got more gear than I need...and I like it!

Elantric

QuotePrototype boards on their way from manufacturing in Asia abt.,$100.
Fantastic price


QuoteAnd just ordered components for abt. $300 from Germany and UK to populate them

Its an investment, and some risk, - but the completed box  will sellout !
and thanks for the good progress report!

CodeSmart

SMD footprints are nightmare. Got the boards and gladly started to solder. Could not fit the tiny Microchip I/O extension SMD component x 3 pcs. No way possible. Also another footprint x 4 pcs was a bit too small. Need to make new main boards ASAP, but will wait until I get all of the components delivered.

I really thought I had checked this :(

Things get really different when you hold the stuff in your hand and start to solder compared to the screen or printed image.

Got to verify the other four smaller boards as well. Hopefully not all of them are electrically useless.
But I got more gear than I need...and I like it!

Elantric

sad to hear the news

SMT devices are a challenge  - and what typically trips you up are the half dozen variation in the available packages

20 years ago you could simply say

This one is SOIC

this smaller one is TSSOP

This one here is QFN,

this one here is BGA - (always avoid for low volume)

If you need help - shoot me any Gerbers and a BOM  - and I'll  review all footprints prior to PCB fab( my day gig)

CodeSmart

Quote from: Elantric on April 23, 2015, 04:30:08 PM
sad to hear the news

Thanks Elantric. I've done the footprint changes to the board but won't dare to send it to production until received all components next week for testing how everything fits the boards and together in the enclosure. Better cover as much as possible in each production round. This is your profession and just my hobby so mistakes happen. However the good thing is I have no timeframe, deadline or boss in this project :-)
But I got more gear than I need...and I like it!

CodeSmart

About to have the second round of boards produced. Even got flaws on the power board, why can't all 3-pin voltage regulators have the same pin out?  I got three types and all with their own different pin order. Of course I screw it up.

I could not stop myself adding circuitry for a second microcontroller on the top board. If I get into memory problems (as Gumtown predicts) this new guy could handle all LCD work, configuration setup etc. to help the other guy out. The two guys may talk and both may access the LCD (great for debugging).

The new guy also has USB host feature so I added footprint for a USB A host connector, in case there could be code for a non-compliant GP-10 MIDI host one day. If ever happens the incoming 5-pin MIDI commands could blend with the GKMX-33 MIDI and output them via USB for GP-10.

As the main board has two MIDI out connectors I also added circuitry making it possible to route if MIDI OUT2 is in parallel with MIDI OUT1 or if it should be connected to the new guy on the top board, allowing incoming MIDI on USB to be directed to the 5-pin MIDI OUT2.

It's getting ridiculously complex without having written a single line of code yet  8)
But I got more gear than I need...and I like it!

gumtown

My 2cents ...

I would hold off on the board design until you have a large chunk of the code written and prototyped on a breadboard,
you may end up changing micro controllers a few times until you have one that matches the project.

If your project gets too software big, may want to consider a micro that supports boot-loader for painless ( and brickless) firmware updates.
Free "GR-55 FloorBoard" editor software from https://sourceforge.net/projects/grfloorboard/

CodeSmart

Quote from: gumtown on May 06, 2015, 12:15:35 AM
I would hold off on the board design until you have a large chunk of the code written and prototyped on a breadboard,

Na, it's tricky putting these tiny guys on a breadboard. This is the MCP4728, a quad 12-bit DAC I'll be using for GK VOL A,B,C and LED background intensity.
Last  night I managed to start the microcontroller on the first crippled main board, write some code for it and is now successfully communicating with this tiny thing over the I2C wires.  ;D
I smile when I see the varying analog voltage levels on the scope. Also my 4x6 channel GTR/Hex volume control chips will be controlled the same way.
Pretty much confident now to produce a second round of boards to awake more functions. Don't want to loose the momentum.


Welcome to my little hobby corner...
But I got more gear than I need...and I like it!

Elantric

Congratulations!


Also - I love your thin Oscilloscope on far left ( pic below)

Whats the Make  / Model?



QuoteWelcome to my little hobby corner...
I can relate


CodeSmart

Quote from: Elantric on May 07, 2015, 04:33:13 PM
Also - I love the Oscilloscope on far right ( pic below)
Whats the Make  / Model?

Just bought it. Need it for this Project. It's working great, small light and does what I expect it to do.
It's German, PeakTech 1245 (100Mhz)  abt. 539 Euro (incl. 19% German VAT) with probes. It has USB, Ethernet and other cool stuff.
This is the next cheapest version. They have up to 300MHz....

http://www.peaktech.de/productdetail/kategorie/digital-oszilloskope/produkt/peaktech-1245.857.html


But I got more gear than I need...and I like it!


CodeSmart

...also got my 6 channel I2C controlled volume chips up and running (they will control the hex level of each synth output as well as regular pups/jack volumes). It seems they are pure monorail. I feed them +/- 5 Volts (as they don't tolerate full GK +/-7V) and need the convert also the digital I2C control lines to +/- 5V using op amps. But they work great, and +/- 5V is enough headroom according to Gumtown heavily hammering his bass. I had hopes they would accept the digital stuff working at normal digital voltages, but hey, they did agree. It looks the AGND and DGND is somewhat related inside the chip. But, I'm still smiling as I watch everything happening and working on my new German oscilloscope  ;D

Life is wonderful except someone is demanding I need to complete the tiles in the basement tomorrow... ::)
But I got more gear than I need...and I like it!

OldGuitarDude


gumbo

Probably not, but he'll check 'em with the oscilloscope later...
Read slower!!!   ....I'm typing as fast as I can...

CodeSmart

Well, I'm checking with laser beam, I hope that's hi-Tech enough ;D

This will be my new Music Room for all my amps and other gear I have laying around the house.
Left pic is when I started working with the floor and walls. Had to broadaxe away the old concrete floor (from 1929),  cast a new floor, and fix the walls.
Right is current state this morning before I cut the tiles for the tile frame towards the walls today.

I've done the rest of the basement a couple of years ago with floor heating (dug away 60 cm below the floor level by hand, heavy blue clay, to put insulation underneath the new concrete floor).
Now there's spa, sauna and a landry room (as said with old amps and guitar gear everywhere).
Now back in the comfy chair doing the final tweaks for the new PCB design (told the Boss my knees hurt)  ;)

But I got more gear than I need...and I like it!

CodeSmart

Four new boards sent to production.  :D

Spent 40 minutes writing a long thing about what MIDI features I was thinking adding to the software but the iPad nuked and killed it. So to be shorter now, this guy will be doing everything if programmed wisely.

The processor knows everything about connected GK device (even the GTR/mix/hex switch), got jacks for 3xFS-6/EV-5 etc. It has a MIDI in and two MIDI outs (and perhaps one day a USB MIDI Host for GP-10).

So now fellows, please hit me with your wet dreams about YOUR V-Guitar MIDI controller. What do you want?, is there something you miss?

(My personal favorite is having S1/S2 (or a FS-6 footswitch) count up/down in 5 positions for COSM pickup selection. Also I may want to invoke S1 as a Hex/GTR kill switch. What's your ideas?)
But I got more gear than I need...and I like it!

gumtown

Input level to midi cc# so the input level/intensity can be used as a variable midi control over parameters or a threshold triggered switch (7 bit A/D on normal guitar input?).
It is a handy option in the Boss GT10/100 where you can play soft and have a clean + delay/reverby tone and as your playing digs harder, it adds more drive and less effect.
It is a feature lacking on the GR-55.
Free "GR-55 FloorBoard" editor software from https://sourceforge.net/projects/grfloorboard/

Tonato

subsonic filters in its inputs and independent GK sensitivity setting per input.

I don't know if this is possible or worth but, midi outputs and you can program to send midi info for change of presets etc in each gk unit.


CodeSmart

Quote from: Tonato on May 11, 2015, 08:52:40 AM
subsonic filters in its inputs and independent GK sensitivity setting per input.

I don't know if this is possible or worth but, midi outputs and you can program to send midi info for change of presets etc in each gk unit.

Subsonic filter, fixed (same I used in GKFX-11) or programmable (20-650Hz individual per string covering any instrument: bass, guitar, violin etc) will be available as well hex flip function if some of the instruments have upside down GK.

All 8 gains/attenuations are programmable / input : Hex(6), GTR(1) and Jack(1). Blending GTR and Jack allows mixing Piezo and pups (if having a dual output guitar). Or route pups through a hi quality guitar cable and nuke GTR signal from 13-pin cable.

MIDI messages will be sent on individually, per command configurable channel. Each synth unit to be programmed to listen to channel of interest.
But I got more gear than I need...and I like it!