ComputerVoltageSources

Are there any ICs or semiconductors in the plan for the PCBs that are
not commonly stocked at Allied/Mouser/DigiKey/Jameco?
If lead times are involved we might wanna get orders in.
I read Grant's early propsal and it all looks like common stock to me
but i'd just like to be sure i have some supplies lined up.
Our colleagues overseas might need to do some translation in their
planning too.

Thanks again to all you folks for pitching in and making this happen
so fast.

-doc
who's already got a nice empty conductive lucite box,
(ahhh the blank canvas!)

All of the LCD Support PCB assembly parts are available from Digi-Key or
Mouser, with one exception. You'll need a programmed Atmel Attiny2313
processor to run the LCD display code.

Does anyone have a bulk burner for these devices?

John Loffink
The Microtonal Synthesis Web Site
http://www.microtonal-synthesis.com
The Wavemakers Synthesizer Web Site
http://www.wavemakers-synth.com

> -----Original Message-----
> From: ComputerVoltageSources@yahoogroups.com
> [mailto:ComputerVoltageSources@yahoogroups.com] On Behalf Of drmabuce
>
> Are there any ICs or semiconductors in the plan for the PCBs that are
> not commonly stocked at Allied/Mouser/DigiKey/Jameco?
> If lead times are involved we might wanna get orders in.
> I read Grant's early propsal and it all looks like common stock to me
> but i'd just like to be sure i have some supplies lined up.
> Our colleagues overseas might need to do some translation in their
> planning too.
>
> Thanks again to all you folks for pitching in and making this happen
> so fast.
>
> -doc
> who's already got a nice empty conductive lucite box,
> (ahhh the blank canvas!)
>

I've never seen a bulk burner for these. I figured I'd just add a zif
socket to my STK500 and program a bunch. They program fast. I'm not
interested in being in the distribution business, though, so perhaps
we could bundle them with the PCB.

Since it's programmed, I sure think we need some early adopter beta
testers to validate everything is OK.

Of course, any one else is free to volunteer to do any of this.

BTW, an ISP programmer for the AVRs is $30 which is pretty reasonable.

Dave

--- In ComputerVoltageSources@yahoogroups.com, "John Loffink"
<jloffink@...> wrote:

> All of the LCD Support PCB assembly parts are available from Digi-

Key or

> Mouser, with one exception. You'll need a programmed Atmel

Attiny2313

> processor to run the LCD display code.
>
> Does anyone have a bulk burner for these devices?

We are just finalizing schematics.

I sent Harry some crude pencil drawings of a starting point.

He is going to massage them to his liking.

Current plan is to support 8 in and 8 outs, both 10 volt and 5 volt ranges with different
resistors.

Unipolar output for simplicity and accuracy.

The only change I see is to move the start PB to IRQ1 input (which is now AUX). That would
allow using an interupt service routine for the start PB.

The old start pin gets used for DAC select to select between the two quad DAC chips.

That still leaves the I2C port uncommited. Does anyone have a neat I2C port expanded they
would like to mention?

Thank you.

I was thinking about the full configuration using 16 potentiometers.
8 input presets and 8 input attenuators. That would be enought to make a nice sequencer if
you could read the two banks of pots as voltage values.

There is actually a trick we could use to keep normal function but read the pots as two banks
of 8. It requires one port line and input jacks with normalized switches.

Use the port line to switch a 10 volt reference from the bank of 8 offset pots (where it is
normally connected) to all the input jacks switch inputs.

This shuts off the offset pots and allows the 8 attenuator pots to be read as voltage values,
while still serving as attenuators under normal circumstance (something plugged into the
input jack).

The offset pot summer values would change to 200K, instead of 301K if the offset pots were
connected to +15V.

Just thought I'd mention it in case Harry thinks it is worth the extra effort.

Unfortunately I2C protocol is a bit more complex than
SPI, so you can't use something as simple as the
74HC595 shift register for it.

However, Maxim makes the MAX6956 which can be used for
input/output and has programmable constant-current
capability for LED driving and available in a DIP:
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3503
available from Digi-Key for ~$8
http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?Ref=81478&Row=445765&Site=US

I2C is also great for memory expansion - the Atmel
AT24CXXX parts are all extremely inexpensive I2C
EEPROM in 8-pin DIP. 64kx8 for about $2 from Digi-Key:
http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?Ref=84768&Row=289729&Site=US

Eric

--- Grant Richter <grichter@...> wrote:

>
> That still leaves the I2C port uncommited. Does
> anyone have a neat I2C port expanded they
> would like to mention?
>

__________________________________________________
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It does sound interesting and prlly does not add much circuitry.

why not include the idea. If the board gets to be impossible we can
discuss it then...

H^) harry



Grant Richter <grichter@...> wrote: I was thinking about the full configuration using 16 potentiometers.
8 input presets and 8 input attenuators. That would be enought to make a nice sequencer if
you could read the two banks of pots as voltage values.

There is actually a trick we could use to keep normal function but read the pots as two banks
of 8. It requires one port line and input jacks with normalized switches.

Use the port line to switch a 10 volt reference from the bank of 8 offset pots (where it is
normally connected) to all the input jacks switch inputs.

This shuts off the offset pots and allows the 8 attenuator pots to be read as voltage values,
while still serving as attenuators under normal circumstance (something plugged into the
input jack).

The offset pot summer values would change to 200K, instead of 301K if the offset pots were
connected to +15V.

Just thought I'd mention it in case Harry thinks it is worth the extra effort.





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[Non-text portions of this message have been removed]

I think the strong preference is for common parts, but if there's
something critical that's difficult to source in one-off quantity (or
if there's a significant savings to be had buying in small bulk) i'd be
willing to coordinate a group buy.

bbob


--- In ComputerVoltageSources@yahoogroups.com, "drmabuce"
<drmabuce@...> wrote:

>
> Are there any ICs or semiconductors in the plan for the PCBs that are
> not commonly stocked at Allied/Mouser/DigiKey/Jameco?
> If lead times are involved we might wanna get orders in.
> I read Grant's early propsal and it all looks like common stock to me
> but i'd just like to be sure i have some supplies lined up.
> Our colleagues overseas might need to do some translation in their
> planning too.
>
> Thanks again to all you folks for pitching in and making this happen
> so fast.
>
> -doc
> who's already got a nice empty conductive lucite box,
> (ahhh the blank canvas!)
>

I second this motion...why not add a couple parts for sequencer
functionality? That would be really useful. Does anyone have any
compelling reasons why not to add this?

-H

On Mar 22, 2006, at 11:01 AM, Harry Bissell Jr wrote:

> It does sound interesting and prlly does not add much circuitry.
>
> why not include the idea. If the board gets to be impossible we can
> discuss it then...
>
> H^) harry
>
>
>
> Grant Richter <grichter@...> wrote: I was thinking
> about the full configuration using 16 potentiometers.
> 8 input presets and 8 input attenuators. That would be enought to
> make a nice sequencer if
> you could read the two banks of pots as voltage values.
>
> There is actually a trick we could use to keep normal function
> but read the pots as two banks
> of 8. It requires one port line and input jacks with normalized
> switches.
>
> Use the port line to switch a 10 volt reference from the bank of
> 8 offset pots (where it is
> normally connected) to all the input jacks switch inputs.
>
> This shuts off the offset pots and allows the 8 attenuator pots
> to be read as voltage values,
> while still serving as attenuators under normal circumstance
> (something plugged into the
> input jack).
>
> The offset pot summer values would change to 200K, instead of
> 301K if the offset pots were
> connected to +15V.
>
> Just thought I'd mention it in case Harry thinks it is worth the
> extra effort.
>
>
>
>
>
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>
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
>
> Yahoo! Groups Links
>
>
>
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>
>

I have always wanted to write a sequencer and was thinking of
converting my AVR synth to a sequencer. With the display and internal
quantization, this would make a great module. Do it - Dave

--- In ComputerVoltageSources@yahoogroups.com, Henry Till <htill@...>
wrote:

>
> I second this motion...why not add a couple parts for sequencer
> functionality? That would be really useful. Does anyone have any
> compelling reasons why not to add this?
>
> -H

--- In ComputerVoltageSources@yahoogroups.com, "Grant Richter"
<grichter@...> wrote:

> Current plan is to support 8 in and 8 outs, both 10 volt and 5
> volt ranges with different resistors.
>
> Unipolar output for simplicity and accuracy.

Can someone explain the current thinking on the input level and
offset? Will this allow me to drive the analog inputs with +/- 5
volt signals? Modulating inputs with LFOs is a reasonable
application. Accuracy isn't overly important for the programs I've
written.

>
> The only change I see is to move the start PB to IRQ1 input (which
> is now AUX). That would allow using an interupt service routine
> for the start PB.

Are you still trying for PSIM compatibility? Personally I use the
start and stop switches / inputs for modes more than start and
stop. I'm not too interested in being able to drive this via
interrupts but I do want to be able to detect a narrow trigger. As
such I would prefer to keep the interrupt on aux. Here's a couple
of thoughts. I have written code to detect edges on timer
interupts. This supports detection of the start, stop, or aux
inputs. The only requirement is that the pulse width needs to be
greater than the interrupt period. For my implementation that is 1
mS or 10 mS. This would be sufficient for switches or gates but not
triggers. The interrupt latency would be minor. Another thought is
to remap the three inputs that support IRQs for all three inputs.
If you are going to change one and impact backwards compatibility,
why not change all three? I don't remember the specific pins but
this would be a minor adjustment to existing code.

> That still leaves the I2C port uncommited. Does anyone have a neat

I2C port expanded they would like to mention?

At this point I would terminate it in a connector for future
expansion. Let's get the basic design in the hands of users and
they'll expand the system based on real needs rather than
anticipation.

Dave

Hi Dave

--- In ComputerVoltageSources@yahoogroups.com, "djbrow54" <davebr@...>
wrote:

> >
> > Unipolar output for simplicity and accuracy.
>
> Can someone explain the current thinking on the input level and
> offset? Will this allow me to drive the analog inputs with +/- 5
> volt signals?

yes...
the Offset knob will allow you to 'lift the floor' of your LFO output
from -5v to 0V, then you just tweak the range/scale knob for best
compatibility with your app. software.

i'll leave your other questions to better qualified heads.

best,
-doc

>
> > That still leaves the I2C port uncommited. Does anyone have a neat
> I2C port expanded they would like to mention?
>
> At this point I would terminate it in a connector for future
> expansion. Let's get the basic design in the hands of users and
> they'll expand the system based on real needs rather than
> anticipation.
>

Agreed about I2C. Let's leave it for expansion.

John Loffink
The Microtonal Synthesis Web Site
http://www.microtonal-synthesis.com
The Wavemakers Synthesizer Web Site
http://www.wavemakers-synth.com

Gang Programmers that support Atmel AVR series exist, but they are not cheap
- several thousand $$$ from what I've found so far.

John Loffink
The Microtonal Synthesis Web Site
http://www.microtonal-synthesis.com
The Wavemakers Synthesizer Web Site
http://www.wavemakers-synth.com

> -----Original Message-----
> From: ComputerVoltageSources@yahoogroups.com
> [mailto:ComputerVoltageSources@yahoogroups.com] On Behalf Of djbrow54
>
> I've never seen a bulk burner for these. I figured I'd just add a zif
> socket to my STK500 and program a bunch. They program fast. I'm not
> interested in being in the distribution business, though, so perhaps
> we could bundle them with the PCB.
>
> Since it's programmed, I sure think we need some early adopter beta
> testers to validate everything is OK.
>
> Of course, any one else is free to volunteer to do any of this.
>
> BTW, an ISP programmer for the AVRs is $30 which is pretty reasonable.
>
> Dave
>
> --- In ComputerVoltageSources@yahoogroups.com, "John Loffink"
> <jloffink@...> wrote:
> > All of the LCD Support PCB assembly parts are available from Digi-
> Key or
> > Mouser, with one exception. You'll need a programmed Atmel
> Attiny2313
> > processor to run the LCD display code.
> >
> > Does anyone have a bulk burner for these devices?
>

wow that's a mighty generous contribution on your part... you sure
are civic minded... :^P

H^) harry (playful tonight :^)

John Loffink wrote:

>
> Gang Programmers that support Atmel AVR series exist, but they are not
> cheap
> - several thousand $$$ from what I've found so far.
>
> John Loffink
> The Microtonal Synthesis Web Site
> http://www.microtonal-synthesis.com
> The Wavemakers Synthesizer Web Site
> http://www.wavemakers-synth.com
>
> > -----Original Message-----
> > From: ComputerVoltageSources@yahoogroups.com
> > [mailto:ComputerVoltageSources@yahoogroups.com] On Behalf Of
> djbrow54
> >
> > I've never seen a bulk burner for these. I figured I'd just add a
> zif
> > socket to my STK500 and program a bunch. They program fast. I'm
> not
> > interested in being in the distribution business, though, so perhaps
> > we could bundle them with the PCB.
> >
> > Since it's programmed, I sure think we need some early adopter beta
> > testers to validate everything is OK.
> >
> > Of course, any one else is free to volunteer to do any of this.
> >
> > BTW, an ISP programmer for the AVRs is $30 which is pretty
> reasonable.
> >
> > Dave
> >
> > --- In ComputerVoltageSources@yahoogroups.com, "John Loffink"
> > <jloffink@...> wrote:
> > > All of the LCD Support PCB assembly parts are available from Digi-
> > Key or
> > > Mouser, with one exception. You'll need a programmed Atmel
> > Attiny2313
> > > processor to run the LCD display code.
> > >
> > > Does anyone have a bulk burner for these devices?
> >
>
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No problem. $3000 divided by 100 programmed parts is only a $30 per chip
surcharge. :-)

We're only joking here folks...

John Loffink
The Microtonal Synthesis Web Site
http://www.microtonal-synthesis.com
The Wavemakers Synthesizer Web Site
http://www.wavemakers-synth.com

> -----Original Message-----
> From: ComputerVoltageSources@yahoogroups.com
> [mailto:ComputerVoltageSources@yahoogroups.com] On Behalf Of harrybissell
>
> wow that's a mighty generous contribution on your part... you sure
> are civic minded... :^P
>
> H^) harry (playful tonight :^)
>
> John Loffink wrote:
> >
> > Gang Programmers that support Atmel AVR series exist, but they are not
> > cheap
> > - several thousand $$$ from what I've found so far.
> >

--- In ComputerVoltageSources@yahoogroups.com, "John Loffink"
<jloffink@...> wrote:

>
> No problem. $3000 divided by 100 programmed parts is only a $30 per

chip

> surcharge. :-)
>
> We're only joking here folks...
>
> John Loffink
> The Microtonal Synthesis Web Site
> http://www.microtonal-synthesis.com
> The Wavemakers Synthesizer Web Site
> http://www.wavemakers-synth.com
>
>
> > -----Original Message-----
> > From: ComputerVoltageSources@yahoogroups.com
> > [mailto:ComputerVoltageSources@yahoogroups.com] On Behalf Of

harrybissell

> >
> > wow that's a mighty generous contribution on your part... you sure
> > are civic minded... :^P
> >
> > H^) harry (playful tonight :^)
> >
> > John Loffink wrote:
> > >
> > > Gang Programmers that support Atmel AVR series exist, but they

are not

> > > cheap
> > > - several thousand $$$ from what I've found so far.
> > >
>

(sorry about the first misfire folks... guess i should put some TEXt
in these messages)

damn....
punked again!
i guess i'm genuine ly overanxious
uh.............. John .... i already sent my check .... would you
please just apply it to my account....
it was written on my 'joke' bank account anyway!
8]

(REALLY KIDDING this time!)

-doc





--- In ComputerVoltageSources@yahoogroups.com, "John Loffink"
<jloffink@...> wrote:

>
> No problem. $3000 divided by 100 programmed parts is only a $30 per

chip

> surcharge. :-)
>
> We're only joking here folks...
>
> John Loffink
> The Microtonal Synthesis Web Site
> http://www.microtonal-synthesis.com
> The Wavemakers Synthesizer Web Site
> http://www.wavemakers-synth.com
>
>
> > -----Original Message-----
> > From: ComputerVoltageSources@yahoogroups.com
> > [mailto:ComputerVoltageSources@yahoogroups.com] On Behalf Of

harrybissell

> >
> > wow that's a mighty generous contribution on your part... you sure
> > are civic minded... :^P
> >
> > H^) harry (playful tonight :^)
> >
> > John Loffink wrote:
> > >
> > > Gang Programmers that support Atmel AVR series exist, but they

are not

> > > cheap

> > > - several thousand $$$ from what I've found so far.
> > >
>