SynthFrog » Core module

Sowing the SIDs of love

aris — Fri, 13 Mar 2009 07:53:00 +0000

All things come to those who wait. But even if you wait for an eternity, no SID will come your way unless you hunt it down because it has been long since it was discontinued! And so I did hunt it!!. Two found and thus, the quest for the MidiBox SID began.

It is a stereo SID synth. Two sids, one for each channel. Made the Core (the old 8 bit), got two 18f4685 (of which I toasted one because I gave it 12 volts!! Thank god I got two) made the boards and TADAAA!!!!

The SID works!! If you play something via midi you get a square lead sound.. nothing special but it is there.. So now I must add buttons and encoders.

The only thing that went wrong apart from the burnt PIC was that the 20×4 blue/white screen I had to put , went cookoo!! Maybe this was a result of the 12 volt jolt! But, no real harm done since I have a spare 40×2 screen.!!

Now I REALLY have to finish the midibox router and midibox sequencer.. I have no excuse, neither does Braska!!

Midibox Day

aris — Wed, 11 Mar 2009 09:00:00 +0000

This is the day of the midibox. I started making 4 MidiIIC modules and 4 Core Modules (pic based)
The four MidiIIC will be used for a midi router (again, a midibox project) I am making.
One of the cores will be used for it too. The other one will be used for a SID engine (with TWO sids!! Stereo!)
(I already found the SIDS). The other two core modules will be used for various experiments and to continue
the (delayed) development of the harmonic table project. Of course Braska is here to help!!!!

The proof of concept

aris — Wed, 26 Nov 2008 23:24:00 +0000

This is the keyboard from the last post with some additional stuff. There is a Core module (midibox.org) and a digital in midibox module that reads the switches. I installed the SDK so I can write a minimal program (midibox is programmed in C and produces hex files, uploadable as system exclusive data to the core). So I connected 4 of the switches to make a quick test and connected them all together. I was sure that both midibox modules were ok because I had the midibox sequencer running on them. The simplistic program just adds 40 to the pin number (the one displayed on the LCD) and outputs this as a note on/off midi signal. When all switches get connected, there will be a need for a mapping between module pins and note numbers so there will be some more programming. For now, a small, quickly made video shows that IT WORKS!

(first video for public viewing, so don’t be so harsh

You can also see it in vimeo here: http://vimeo.com/2357167

AVRSynth 32 PCB

aris — Mon, 10 Nov 2008 10:32:00 +0000

Collin Mel and myself , have designed a PCB layout for AVRSynth, instead of doing it on perfboard. It hasn’t been proofed and debugged yet but I am on the process. If you feel adventurous and/or lucky, you can download the eagle files from here
and try yourself!. Please do tell me about possible bugs you may encounter.

I exposed the photosensitive board covered with a transparency with the PCB layout printed on. I used two transparencies, one stacked on top of the other for extra opaqueness. Still there is a little UV light going through, you may see it on the photos as the copper is a little spotty. No electrical flaws though, but I think, another layer would do a better job.
I developed the exposed board with a solution of 1 teaspoon of pipe cleaner (branded TUB.O.FLO locally) but which contains NaOH. When developed, I etched it using a 14% HCl solution (also a cleaning product) and dropped in it a small cup of concentrated Peroxide. (Named localy “Peridrol”). If interested I can delve in much more detail on the etching process. Just be ware of the fumes and liquids, so work in a well ventilated area, stay AWAY from children (you and the chemicals) and store them out of their reach. These chemicals are highly toxic and caustic and I don’t want to be held responsible for any misusage of the components.

This is how it looks while ethcing.. Beware of them bubbles. They stink and for a reason. DO NOT inhale close to them.

This is the finished PCB, without any components on it. I will post photos of the component mounting process and hope it works the first time

When this is finished, a core midibox module will take care of the midi messages that are needed to have access to the AVRSynth32 functions that are not available through it’s pots. (such as cutoff, resonance, ADSR params etc.)

Switches!!!!

aris — Thu, 06 Nov 2008 21:57:00 +0000

Switches came. Tact switches for many purposes… The midibox Seq waits for some of them. The c-music axis clone, for most of them, and maybe a mini keyboard for one of the synths. Hey you could even make a guitar fretboard with them, they are just the right size.

For making stuff with switches, midibox ruleZ!!!!

A working core module

aris — Thu, 23 Oct 2008 10:15:00 +0000

PCB Oven output.

aris — Thu, 23 Oct 2008 10:11:00 +0000

Both are midibox core modules, both are working even with the slight fixes made on the right one . One serves now as the brain for the sequencer and the other one for more experimental stuff. (That is: my non-working programs

CORE module and TV

aris — Thu, 23 Oct 2008 10:05:00 +0000

The midibox Core module is a monster of usability. It is a hardware core component and a software library that can turn the chip into a powerful midi/controller machine. There is a very active community that writes programms and creates modules and applications. The mastermind behind the midibox is T. Klose (and I wonder what kind of guy he is, providing such stuff for FREE!!!! )

So, there is a small application that turns the core module into a video signal generator with the apparent results shown above. I put it in the core and caught myself staring at the results in awe! (and then reprogrammed the core to do something more useful