News:

SMF for DIYStompboxes.com!

Main Menu

PROJECT: Crossbar

Started by Peter Snowberg, March 12, 2006, 09:44:28 PM

Previous topic - Next topic

puretube

"I was looking back to see if you were looking back to see if I was looking back at you..."  :icon_smile:

happy easter!

Gripp

Quote from: Chuck on April 07, 2007, 05:52:22 PM
Comments anyone?  Its wierd that there are thousands of views but no comments....

What can one say? Simply awesome!!
..and a scarily tidy workbench too.

Best!
Pelle


KB

I have to agree with Gripp

This is awesome. 

This is something that I dream about being able to make for myself...

Congrats on the progress so far, looking forward to seeing the end result.

Kevin.

Iojan


Chuck

Just as and update, I was away to California for a week so i haven't been doing much.
I did get the PIC talking to the MT8816 this weekend.  So communications is all working and my circuit works so far.
Now its just a matter of coding, which I'm getting back into.

R.G.

Tee - hee...

It's just A Simple Matter Of Programming, right?
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

Chuck

R.G.,
Yep.  :)  But what keeps me motivated is showing you what I can do.   

I am at the part you described about twenty messages ago.  I have a working circuit.

Quote from: R.G. on February 24, 2007, 03:24:08 PM
Getting user interface that you understand this week is easy. Getting one that you understand in a year is hard. Getting one that a person who hasn't read the manual can do is... HARD.

I may have to steal the java gui frontend from the Sound Sculpture Switchblade.... No that would be cheating.  I figure I'm going to need a user interface with an alphabet scroll for input.

It is starting to bother me that I used a serial interface instead of a parallel, I hope its fast enough.

Chuck

A lot of headway this weekend.
Well it all works!

Things are a bit more cluttered now.
http://www.voodooengineering.com/release/cluttered.jpg

I had to use a Logic Analyser on the PC pictured to sort out the timing.
The serial commands are not too slow, in fact they are a little too fast for the MT8816.
I had to slow down the strobe using a ms of delay to keep it stable.
http://www.voodooengineering.com/release/cluttered2.jpg

I'm currently switching from two patch setups.

Guitar to Amp
Gutar to Destortion Pedal to Amp

It switches fast and clean without an popping even and I'm not grounding out the Amp between switching like R.G. discussed.
(Though that may still be needed with longer patches.)
The ribbon cable I'm using to connect the audio I/O boards to the router board isn't affecting tone or sound at all.
When I scope the before and after audio signals the traces are identical.

I need to make the test I/O board with more input and outputs and hit Mouser for some more jacks.
I also need to add 8 EEPROMs to store the patches and recall them.
I figure I'll use the 24LC512 EEPROM and stack them up for 512k of memory.
So I'll probably draw up a couple more boards to send out to ExpressPCB this week.

I also got some cool navigation switches from Sweden this week for providing user input.
http://www.voodooengineering.com/release/h29194.jpg

Still working on the user configuration code, but I got some ideas now that I'm actually setting up patches.
I think at first I'll provide a user screen to name the effects and assign the jack pairs.
Then a user screen to select the effects and put them into a chain, then write it to a memory bank/channel.

kunkler99

Hey chuck are you going to offer this for us to build after you get it done? This is exactly what I have been looking for!! You said in a past post you might have some extra boards? How much?? Thanks Scott

Chuck

Scott,
Yeah, I was thinking about writing it up when I'm done with this research phase.
Probably on the midibox site -- since thats where I really started this from.
I realy don't know how I wound up here -- probably R.G's comments.

I'm working on redrawing the router board now, so i can add the charge pump circuit and the EEPROMs.
There are actually 5 board which comprise the system.  CPU, user IO, Router and 2 boards of 8 audio jacks.

If you want an early start send me a PM.

Chuck

Dave_B

The Swedish switch is very nice.  Do you mind saying where you bought it?  I found the E-switch nav switch while doing a search, but it's not nearly as cool or (seemingly) easy to mount in a box.

I imagine this project has a lot of crossover appeal.  I can see this living comfortably on a number of different forums. 
Help build our Wiki!

Chuck

I got them at Elfa.

http://www.elfa.se/elfa-bin/setpage.pl?http://www.elfa.se/elfa-bin/dyndok.pl?dok=11617.htm

In sweden.  Pretty qucik actually.

A module are complete, you don't need extra caps.

Chuck

kunkler99

Hey chuck how it coming along?

Chuck

At this point in time I'm working about 3-4 hours a week on this.
It may be like this for the summer.  There really is only coding to do.
I consider the hardware ready for one last board milling.

Chuck

R.G.

People don't really appreciate the sarcasm in "a simple matter of programming" until they get into programming, do they?

I feel for you Chuck.

Are you using one of the one- or two-line LCDs for annunciation?
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

Chuck


It would be nothing to simply hard code the whole thing and change the code everytime I want to setup new patch chains.
But I'm putting some effort into a real user interface.

Two lines is all I can fit into a 1 RU case.  I have a 40 character or an 80 character two line LCD to choose from.
Right now I'm trying to fit it into a 40 character one.  I'm attempting to create a alpha numeric routine to choose letters in a name.

I got distracted by ordering a Egnater M4 and buying a VHT 2150.  So I'll probably build a road case for those before even coming close to finishing this switch.  Right now my wife has me stripping kitchen cabinets.

Thanks for the sentiment.  :)

KB

Quote from: Chuck on May 25, 2007, 09:27:48 AM

Right now my wife has me stripping kitchen cabinets.


Been there, done that..... feel for you... :icon_biggrin:

will keep watching the progress.... Looking forward to seeing the completed switching unit.

I still cannot get a little one working, and all I had to do was program a PIC, with the supplied code....

Kevin

Dave_B

Quote from: KB on May 25, 2007, 11:07:38 AMall I had to do was program a PIC, with the supplied code....
Did the supplied code mention anything about how to set the fuses?  I'm no longer that familiar with PIC's but that's a pretty common issue if you haven't done it before.
Help build our Wiki!

Chuck

Quote from: KB on May 25, 2007, 11:07:38 AM
Quote from: Chuck on May 25, 2007, 09:27:48 AM

Right now my wife has me stripping kitchen cabinets.


Been there, done that..... feel for you... :icon_biggrin:

Yeah, its taking me about 2 hours per cabinet and I can do two before running out of steam for the day.  4 down, 12 to go.