Synth-DIY Yahoo! Groups Archives

Thread

SynthonaChip demo

2019-01-28 by Synthetech

Hey Mike,

I noticed it's been awful quiet on the yahoogroups. Been busy?

I've been working on and off on this STM32F4 synth chip.

It's been a slow progress, but I think I may have something almost usable here.

Here is a private/unlisted video..

https://youtu.be/Z6L2gvHk7sw

I'm keeping this quiet for now because I'm not sure if I want to share the work I've done so far with the public.

Anyway, take a look and let me know what you think.

/Blaine

Re: [korgpolyex] SynthonaChip demo

2019-01-29 by support

Hi Blaine,

it's great work! I am in the process of testing a new board for the Poly-800 that is based on an STM32F4 too! The design doesn't give the Poly any new DCO waveforms so I am very interested in your work and how we could collaborate. I would imagine it would be great to take what you have done and develop it into a board to go into the Poly.

Let me know what you think about that.

/Mike

On Sun, 2019-01-27 at 20:57 -0600, Synthetech bperkins211@... [korgpolyex] wrote:

Hey Mike,

I noticed it's been awful quiet on the yahoogroups. Been busy?

I've been working on and off on this STM32F4 synth chip.
It's been a slow progress, but I think I may have something almost usable here.

Here is a private/unlisted video..

https://youtu.be/Z6L2gvHk7sw

I'm keeping this quiet for now because I'm not sure if I want to share the work I've done so far with the public.

Anyway, take a look and let me know what you think.

/Blaine

Re: [korgpolyex] SynthonaChip demo

2019-01-29 by Synthetech

Hi Mike,

I would be interested in collaborating with you. Did you have anything in mind or any details?

I am still ironing things out with this.. but I believe in another month or so it will be working much more smoothly.

It's slow going. I only have some evenings and weekends to dive into the coding. I've been learning alot along the way.

It's taken a long time just to study the code to understand it enough to dive in and modify it the way I want it to work.

Every night I mess around with it, it gets a bit better :).

Honestly I didnt think I'd ever get it working, but I just kept at it and very surprised at the results.

It could be possible to use a smaller chip, the F405RG instead of a 407. Get pin size down to 64 instead of 100.

The possibilities can be very interesting. This synth could be mixed in with the Poly's original DCO's and perhaps have a way to selectively run it through the Analog Filter chip.

Of course the built in FX wont be much good if you used them while running it thru the Poly's VCF.

It's also very possible to make a standalone version too.. Could be a side project that people would be interested in.. a cheaper Shruthi.

I just got in the $1.08 16/24bit stereo DACs from DigiKey. I'll have to wait a few weeks for some breakout boards I bought on ChinaEbay to mount/test them.

Unbelievably cheap how much this stuff is now.

I have a ton of ideas, very interested in hearing yours.

/Blaine

On Mon, Jan 28, 2019 at 6:09 PM support support@... [korgpolyex] <korgpolyex@yahoogroups.com> wrote:

Hi Blaine,

it's great work! I am in the process of testing a new board for the Poly-800 that is based on an STM32F4 too! The design doesn't give the Poly any new DCO waveforms so I am very interested in your work and how we could collaborate. I would imagine it would be great to take what you have done and develop it into a board to go into the Poly.

Let me know what you think about that.

/Mike

On Sun, 2019-01-27 at 20:57 -0600, Synthetech bperkins211@... [korgpolyex] wrote:

Hey Mike,

I noticed it's been awful quiet on the yahoogroups. Been busy?

I've been working on and off on this STM32F4 synth chip.
It's been a slow progress, but I think I may have something almost usable here.

Here is a private/unlisted video..

https://youtu.be/Z6L2gvHk7sw

I'm keeping this quiet for now because I'm not sure if I want to share the work I've done so far with the public.

Anyway, take a look and let me know what you think.

/Blaine

Re: [korgpolyex] SynthonaChip demo

2019-01-30 by support

Hi Blaine,

See the picture. This is the CPU replacement for the Poly-800. I just ordered 100 pieces to begin testing the hardware and writing new software.

The board is based on the STM32F4. Poly-800 owners will have to remove the 80C85 CPU and pop this unit in.

With this installed, there is enormous potential to give the Poly new voices. Much like you said below. We could place new voices before, after or in parallel with the Korg filter.

Clearly, you have done a large amount of the work. And I don't believe in reinventing the wheel. So I would hope that we could come up with some way to integrate our activities in some way.

For one thing, I would like to see if it is feasible to drive a dual D2A via my board. If that is possible, then I could probably reuse most of your code.

On Tue, 2019-01-29 at 17:51 -0600, Synthetech bperkins211@... [korgpolyex] wrote:

Hi Mike,

I would be interested in collaborating with you. Did you have anything in mind or any details?

I am still ironing things out with this.. but I believe in another month or so it will be working much more smoothly.
It's slow going. I only have some evenings and weekends to dive into the coding. I've been learning alot along the way.
It's taken a long time just to study the code to understand it enough to dive in and modify it the way I want it to work.
Every night I mess around with it, it gets a bit better :).
Honestly I didnt think I'd ever get it working, but I just kept at it and very surprised at the results.

It could be possible to use a smaller chip, the F405RG instead of a 407. Get pin size down to 64 instead of 100.

The possibilities can be very interesting. This synth could be mixed in with the Poly's original DCO's and perhaps have a way to selectively run it through the Analog Filter chip.
Of course the built in FX wont be much good if you used them while running it thru the Poly's VCF.
It's also very possible to make a standalone version too.. Could be a side project that people would be interested in.. a cheaper Shruthi.

I just got in the $1.08 16/24bit stereo DACs from DigiKey. I'll have to wait a few weeks for some breakout boards I bought on ChinaEbay to mount/test them.
Unbelievably cheap how much this stuff is now.

I have a ton of ideas, very interested in hearing yours.

/Blaine

On Mon, Jan 28, 2019 at 6:09 PM support support@... [korgpolyex] <korgpolyex@yahoogroups.com> wrote:

Hi Blaine,

it's great work! I am in the process of testing a new board for the Poly-800 that is based on an STM32F4 too! The design doesn't give the Poly any new DCO waveforms so I am very interested in your work and how we could collaborate. I would imagine it would be great to take what you have done and develop it into a board to go into the Poly.

Let me know what you think about that.

/Mike

On Sun, 2019-01-27 at 20:57 -0600, Synthetech bperkins211@... [korgpolyex] wrote:

Hey Mike,

I noticed it's been awful quiet on the yahoogroups. Been busy?

I've been working on and off on this STM32F4 synth chip.
It's been a slow progress, but I think I may have something almost usable here.

Here is a private/unlisted video..

https://youtu.be/Z6L2gvHk7sw

I'm keeping this quiet for now because I'm not sure if I want to share the work I've done so far with the public.

Anyway, take a look and let me know what you think.

/Blaine

Re: [korgpolyex] SynthonaChip demo

2019-01-30 by Synthetech

Mike, what F4 chip are you using?

A dual DAC I drive uses a I2S port. It is driven via interrupt triggered DMA.

The bit rate/clock is approx 1.4Mhz for 44.1Khz stereo sample rate.

That DMA works great but it doesn't leave much time between interrupts to do other things.. especially if they are slow processes.

Sounds like you ordered a lot of boards.. Kinda has you locked in for the design?

/Blaine

On Jan 30, 2019 8:44 AM, "support support@... [korgpolyex]" <korgpolyex@yahoogroups.com> wrote:

Hi Blaine,

See the picture. This is the CPU replacement for the Poly-800. I just ordered 100 pieces to begin testing the hardware and writing new software.
The board is based on the STM32F4. Poly-800 owners will have to remove the 80C85 CPU and pop this unit in.

With this installed, there is enormous potential to give the Poly new voices. Much like you said below. We could place new voices before, after or in parallel with the Korg filter.

Clearly, you have done a large amount of the work. And I don't believe in reinventing the wheel. So I would hope that we could come up with some way to integrate our activities in some way.

For one thing, I would like to see if it is feasible to drive a dual D2A via my board. If that is possible, then I could probably reuse most of your code.

On Tue, 2019-01-29 at 17:51 -0600, Synthetech bperkins211@... [korgpolyex] wrote:

Hi Mike,

I would be interested in collaborating with you. Did you have anything in mind or any details?

I am still ironing things out with this.. but I believe in another month or so it will be working much more smoothly.
It's slow going. I only have some evenings and weekends to dive into the coding. I've been learning alot along the way.
It's taken a long time just to study the code to understand it enough to dive in and modify it the way I want it to work.
Every night I mess around with it, it gets a bit better :).
Honestly I didnt think I'd ever get it working, but I just kept at it and very surprised at the results.

It could be possible to use a smaller chip, the F405RG instead of a 407. Get pin size down to 64 instead of 100.

The possibilities can be very interesting. This synth could be mixed in with the Poly's original DCO's and perhaps have a way to selectively run it through the Analog Filter chip.
Of course the built in FX wont be much good if you used them while running it thru the Poly's VCF.
It's also very possible to make a standalone version too.. Could be a side project that people would be interested in.. a cheaper Shruthi.

I just got in the $1.08 16/24bit stereo DACs from DigiKey. I'll have to wait a few weeks for some breakout boards I bought on ChinaEbay to mount/test them.
Unbelievably cheap how much this stuff is now.

I have a ton of ideas, very interested in hearing yours.

/Blaine

On Mon, Jan 28, 2019 at 6:09 PM support support@... [korgpolyex] <korgpolyex@yahoogroups.com> wrote:

Hi Blaine,

it's great work! I am in the process of testing a new board for the Poly-800 that is based on an STM32F4 too! The design doesn't give the Poly any new DCO waveforms so I am very interested in your work and how we could collaborate. I would imagine it would be great to take what you have done and develop it into a board to go into the Poly.

Let me know what you think about that.

/Mike

On Sun, 2019-01-27 at 20:57 -0600, Synthetech bperkins211@... [korgpolyex] wrote:

Hey Mike,

I noticed it's been awful quiet on the yahoogroups. Been busy?

I've been working on and off on this STM32F4 synth chip.
It's been a slow progress, but I think I may have something almost usable here.

Here is a private/unlisted video..

https://youtu.be/Z6L2gvHk7sw

I'm keeping this quiet for now because I'm not sure if I want to share the work I've done so far with the public.

Anyway, take a look and let me know what you think.

/Blaine

Re: [korgpolyex] SynthonaChip demo

2019-01-30 by support

The board itself is OK for what it needs to do now. Which is to dramatically improve envelopes, sequencer, LFO's, velocity, modulators etc etc.

With that in place, I can add hardware (not to the CPU board) that will be wired in to the main board. Much like the AtomaHawk but a much more powerful board.

This could include a "voice board" that will be modular and allow different options. Your results so far look fantastic, especially as a foundation.

/Mike

On Wed, 2019-01-30 at 10:25 -0600, Synthetech bperkins211@... [korgpolyex] wrote:

Mike, what F4 chip are you using?

A dual DAC I drive uses a I2S port. It is driven via interrupt triggered DMA.
The bit rate/clock is approx 1.4Mhz for 44.1Khz stereo sample rate.
That DMA works great but it doesn't leave much time between interrupts to do other things.. especially if they are slow processes.

Sounds like you ordered a lot of boards.. Kinda has you locked in for the design?

/Blaine

On Jan 30, 2019 8:44 AM, "support support@... [korgpolyex]" <korgpolyex@yahoogroups.com> wrote:

Hi Blaine,

See the picture. This is the CPU replacement for the Poly-800. I just ordered 100 pieces to begin testing the hardware and writing new software.
The board is based on the STM32F4. Poly-800 owners will have to remove the 80C85 CPU and pop this unit in.

With this installed, there is enormous potential to give the Poly new voices. Much like you said below. We could place new voices before, after or in parallel with the Korg filter.

Clearly, you have done a large amount of the work. And I don't believe in reinventing the wheel. So I would hope that we could come up with some way to integrate our activities in some way.

For one thing, I would like to see if it is feasible to drive a dual D2A via my board. If that is possible, then I could probably reuse most of your code.

On Tue, 2019-01-29 at 17:51 -0600, Synthetech bperkins211@... [korgpolyex] wrote:

Hi Mike,

I would be interested in collaborating with you. Did you have anything in mind or any details?

I am still ironing things out with this.. but I believe in another month or so it will be working much more smoothly.
It's slow going. I only have some evenings and weekends to dive into the coding. I've been learning alot along the way.
It's taken a long time just to study the code to understand it enough to dive in and modify it the way I want it to work.
Every night I mess around with it, it gets a bit better :).
Honestly I didnt think I'd ever get it working, but I just kept at it and very surprised at the results.

It could be possible to use a smaller chip, the F405RG instead of a 407. Get pin size down to 64 instead of 100.

The possibilities can be very interesting. This synth could be mixed in with the Poly's original DCO's and perhaps have a way to selectively run it through the Analog Filter chip.
Of course the built in FX wont be much good if you used them while running it thru the Poly's VCF.
It's also very possible to make a standalone version too.. Could be a side project that people would be interested in.. a cheaper Shruthi.

I just got in the $1.08 16/24bit stereo DACs from DigiKey. I'll have to wait a few weeks for some breakout boards I bought on ChinaEbay to mount/test them.
Unbelievably cheap how much this stuff is now.

I have a ton of ideas, very interested in hearing yours.

/Blaine

On Mon, Jan 28, 2019 at 6:09 PM support support@... [korgpolyex] <korgpolyex@yahoogroups.com> wrote:

Hi Blaine,

it's great work! I am in the process of testing a new board for the Poly-800 that is based on an STM32F4 too! The design doesn't give the Poly any new DCO waveforms so I am very interested in your work and how we could collaborate. I would imagine it would be great to take what you have done and develop it into a board to go into the Poly.

Let me know what you think about that.

/Mike

On Sun, 2019-01-27 at 20:57 -0600, Synthetech bperkins211@... [korgpolyex] wrote:

Hey Mike,

I noticed it's been awful quiet on the yahoogroups. Been busy?

I've been working on and off on this STM32F4 synth chip.
It's been a slow progress, but I think I may have something almost usable here.

Here is a private/unlisted video..

https://youtu.be/Z6L2gvHk7sw

I'm keeping this quiet for now because I'm not sure if I want to share the work I've done so far with the public.

Anyway, take a look and let me know what you think.

/Blaine

Re: [korgpolyex] SynthonaChip demo

2019-01-30 by Synthetech

I follow you now..

Currently I have control over the parameters via MIDI CCs.

But they will run out fast with all the options I can fit in. Especially if I create a bank of ADSRs for the FM synth.

I was thinking simplifying it down a bit may be better.

What communication did you have in mind between the uC's?

Just last night I got the amp EG working right.

Now I need to make a VCF EG..

I have basic sine wave modulation for VCF, amp and pitch.. need to make ramps and squares.

I will be sure to make another video soon to demo the new features.

Oh... I have been coding this using CubeMx and HAL with that A6 Eclipse ide.

What have you been using?

On Jan 30, 2019 11:58 AM, "support support@... [korgpolyex]" <korgpolyex@yahoogroups.com> wrote:

The board itself is OK for what it needs to do now. Which is to dramatically improve envelopes, sequencer, LFO's, velocity, modulators etc etc.

With that in place, I can add hardware (not to the CPU board) that will be wired in to the main board. Much like the AtomaHawk but a much more powerful board.

This could include a "voice board" that will be modular and allow different options. Your results so far look fantastic, especially as a foundation.

/Mike

On Wed, 2019-01-30 at 10:25 -0600, Synthetech bperkins211@... [korgpolyex] wrote:

Mike, what F4 chip are you using?

A dual DAC I drive uses a I2S port. It is driven via interrupt triggered DMA.
The bit rate/clock is approx 1.4Mhz for 44.1Khz stereo sample rate.
That DMA works great but it doesn't leave much time between interrupts to do other things.. especially if they are slow processes.

Sounds like you ordered a lot of boards.. Kinda has you locked in for the design?

/Blaine

On Jan 30, 2019 8:44 AM, "support support@... [korgpolyex]" <korgpolyex@yahoogroups.com> wrote:

Hi Blaine,

See the picture. This is the CPU replacement for the Poly-800. I just ordered 100 pieces to begin testing the hardware and writing new software.
The board is based on the STM32F4. Poly-800 owners will have to remove the 80C85 CPU and pop this unit in.

With this installed, there is enormous potential to give the Poly new voices. Much like you said below. We could place new voices before, after or in parallel with the Korg filter.

Clearly, you have done a large amount of the work. And I don't believe in reinventing the wheel. So I would hope that we could come up with some way to integrate our activities in some way.

For one thing, I would like to see if it is feasible to drive a dual D2A via my board. If that is possible, then I could probably reuse most of your code.

On Tue, 2019-01-29 at 17:51 -0600, Synthetech bperkins211@... [korgpolyex] wrote:

Hi Mike,

I would be interested in collaborating with you. Did you have anything in mind or any details?

I am still ironing things out with this.. but I believe in another month or so it will be working much more smoothly.
It's slow going. I only have some evenings and weekends to dive into the coding. I've been learning alot along the way.
It's taken a long time just to study the code to understand it enough to dive in and modify it the way I want it to work.
Every night I mess around with it, it gets a bit better :).
Honestly I didnt think I'd ever get it working, but I just kept at it and very surprised at the results.

It could be possible to use a smaller chip, the F405RG instead of a 407. Get pin size down to 64 instead of 100.

The possibilities can be very interesting. This synth could be mixed in with the Poly's original DCO's and perhaps have a way to selectively run it through the Analog Filter chip.
Of course the built in FX wont be much good if you used them while running it thru the Poly's VCF.
It's also very possible to make a standalone version too.. Could be a side project that people would be interested in.. a cheaper Shruthi.

I just got in the $1.08 16/24bit stereo DACs from DigiKey. I'll have to wait a few weeks for some breakout boards I bought on ChinaEbay to mount/test them.
Unbelievably cheap how much this stuff is now.

I have a ton of ideas, very interested in hearing yours.

/Blaine

On Mon, Jan 28, 2019 at 6:09 PM support support@... [korgpolyex] <korgpolyex@yahoogroups.com> wrote:

Hi Blaine,

it's great work! I am in the process of testing a new board for the Poly-800 that is based on an STM32F4 too! The design doesn't give the Poly any new DCO waveforms so I am very interested in your work and how we could collaborate. I would imagine it would be great to take what you have done and develop it into a board to go into the Poly.

Let me know what you think about that.

/Mike

On Sun, 2019-01-27 at 20:57 -0600, Synthetech bperkins211@... [korgpolyex] wrote:

Hey Mike,

I noticed it's been awful quiet on the yahoogroups. Been busy?

I've been working on and off on this STM32F4 synth chip.
It's been a slow progress, but I think I may have something almost usable here.

Here is a private/unlisted video..

https://youtu.be/Z6L2gvHk7sw

I'm keeping this quiet for now because I'm not sure if I want to share the work I've done so far with the public.

Anyway, take a look and let me know what you think.

/Blaine

Re: [korgpolyex] SynthonaChip demo

2019-01-30 by support

I have other projects going that use Eclipse with SDCC.

The big challenge I have right now is making a choice. Do I create a 80C85 emulator/compiler that runs inside the STM32? Or rewrite the whole thing into C?

The board I've created emulates the data/address and control signals of the 80C85. So whatever I/we create has to work with that.

So for example, I believe that the new sound module will probably plug into where the MSM5232 is. Perhaps keep the MSM5232 sitting next to the new TG. Maybe just have the new board emulate the MSM5232 and provide new voices too. More decisions to make. Either way, the existing computer busses will be the control plane.

Or, we could replace the entire inside of the Poly-800! Imagine that!

/Mike

On Wed, 2019-01-30 at 12:26 -0600, Synthetech bperkins211@... [korgpolyex] wrote:

I follow you now..

Currently I have control over the parameters via MIDI CCs.
But they will run out fast with all the options I can fit in. Especially if I create a bank of ADSRs for the FM synth.
I was thinking simplifying it down a bit may be better.

What communication did you have in mind between the uC's?

Just last night I got the amp EG working right.
Now I need to make a VCF EG..
I have basic sine wave modulation for VCF, amp and pitch.. need to make ramps and squares.

I will be sure to make another video soon to demo the new features.

Oh... I have been coding this using CubeMx and HAL with that A6 Eclipse ide.
What have you been using?

On Jan 30, 2019 11:58 AM, "support support@... [korgpolyex]" <korgpolyex@yahoogroups.com> wrote:

The board itself is OK for what it needs to do now. Which is to dramatically improve envelopes, sequencer, LFO's, velocity, modulators etc etc.

With that in place, I can add hardware (not to the CPU board) that will be wired in to the main board. Much like the AtomaHawk but a much more powerful board.

This could include a "voice board" that will be modular and allow different options. Your results so far look fantastic, especially as a foundation.

/Mike

On Wed, 2019-01-30 at 10:25 -0600, Synthetech bperkins211@... [korgpolyex] wrote:

Mike, what F4 chip are you using?

A dual DAC I drive uses a I2S port.. It is driven via interrupt triggered DMA.
The bit rate/clock is approx 1.4Mhz for 44.1Khz stereo sample rate.
That DMA works great but it doesn't leave much time between interrupts to do other things.. especially if they are slow processes.

Sounds like you ordered a lot of boards.. Kinda has you locked in for the design?

/Blaine

On Jan 30, 2019 8:44 AM, "support support@... [korgpolyex]" <korgpolyex@yahoogroups.com> wrote:

Hi Blaine,

See the picture. This is the CPU replacement for the Poly-800. I just ordered 100 pieces to begin testing the hardware and writing new software.
The board is based on the STM32F4. Poly-800 owners will have to remove the 80C85 CPU and pop this unit in.

With this installed, there is enormous potential to give the Poly new voices. Much like you said below. We could place new voices before, after or in parallel with the Korg filter.

Clearly, you have done a large amount of the work. And I don't believe in reinventing the wheel. So I would hope that we could come up with some way to integrate our activities in some way.

For one thing, I would like to see if it is feasible to drive a dual D2A via my board. If that is possible, then I could probably reuse most of your code.

On Tue, 2019-01-29 at 17:51 -0600, Synthetech bperkins211@... [korgpolyex] wrote:

Hi Mike,

I would be interested in collaborating with you. Did you have anything in mind or any details?

I am still ironing things out with this.. but I believe in another month or so it will be working much more smoothly.
It's slow going. I only have some evenings and weekends to dive into the coding. I've been learning alot along the way.
It's taken a long time just to study the code to understand it enough to dive in and modify it the way I want it to work.
Every night I mess around with it, it gets a bit better :).
Honestly I didnt think I'd ever get it working, but I just kept at it and very surprised at the results.

It could be possible to use a smaller chip, the F405RG instead of a 407. Get pin size down to 64 instead of 100.

The possibilities can be very interesting. This synth could be mixed in with the Poly's original DCO's and perhaps have a way to selectively run it through the Analog Filter chip.
Of course the built in FX wont be much good if you used them while running it thru the Poly's VCF.
It's also very possible to make a standalone version too.. Could be a side project that people would be interested in.. a cheaper Shruthi.

I just got in the $1.08 16/24bit stereo DACs from DigiKey. I'll have to wait a few weeks for some breakout boards I bought on ChinaEbay to mount/test them.
Unbelievably cheap how much this stuff is now.

I have a ton of ideas, very interested in hearing yours.

/Blaine

On Mon, Jan 28, 2019 at 6:09 PM support support@... [korgpolyex] <korgpolyex@yahoogroups.com> wrote:

Hi Blaine,

it's great work! I am in the process of testing a new board for the Poly-800 that is based on an STM32F4 too! The design doesn't give the Poly any new DCO waveforms so I am very interested in your work and how we could collaborate. I would imagine it would be great to take what you have done and develop it into a board to go into the Poly.

Let me know what you think about that.

/Mike

On Sun, 2019-01-27 at 20:57 -0600, Synthetech bperkins211@... [korgpolyex] wrote:

Hey Mike,

I noticed it's been awful quiet on the yahoogroups. Been busy?

I've been working on and off on this STM32F4 synth chip.
It's been a slow progress, but I think I may have something almost usable here.

Here is a private/unlisted video..

https://youtu.be/Z6L2gvHk7sw

I'm keeping this quiet for now because I'm not sure if I want to share the work I've done so far with the public.

Anyway, take a look and let me know what you think.

/Blaine

Re: [korgpolyex] SynthonaChip demo

2019-01-30 by Synthetech

It sounds like there would be no problem getting the two to talk with each other.

Right now I have a standard 31250 8bit 1 stop bit non parity serial port to receive MIDI.

Its Rx only right now, but I can add Tx in if needed.

I can change that baud rate with one value change.

I figure if you can Rx/Tx MIDI, then there should be no problem passing on MIDI notes and CC's.

And custom codes should be easy too.

I would think keeping it as simple as possible would be best.

If you replace the entire board in the Poly800, I dont think that would be a popular Option. May as well buy another synth.. unless I am missing something.

The Poly just isnt that great a set of keys IMO and no velocity.

But to make it something unique, utilizes that analog filter.. I think that would garner attention.

I thought I would also mention, I have access at work to make custom enclosures.

The pics attached show a couple small simple enclosures used for aircraft electronics we build. Also is a pic of the grimy shop the equipment is in.

I spoke with one of the fellas that knows how to use the metalwork machines and he said he could take a look at what I envision as a rack unit to put Poly/Ex boards inside with the Jack ports on the back and LCD screen/pots/encoders/buttons for the front.

I'm not sure what costs would be, but I could look into it.

Just something to think about...

I'm going to get some tinkering going again tonight. Hopefully get Pitch Bend working.

TTYL

/Blaine

On Wed, Jan 30, 2019 at 2:18 PM support support@... [korgpolyex] <korgpolyex@yahoogroups.com> wrote:

I have other projects going that use Eclipse with SDCC.

The big challenge I have right now is making a choice. Do I create a 80C85 emulator/compiler that runs inside the STM32? Or rewrite the whole thing into C?

The board I've created emulates the data/address and control signals of the 80C85. So whatever I/we create has to work with that.

So for example, I believe that the new sound module will probably plug into where the MSM5232 is. Perhaps keep the MSM5232 sitting next to the new TG. Maybe just have the new board emulate the MSM5232 and provide new voices too. More decisions to make. Either way, the existing computer busses will be the control plane.

Or, we could replace the entire inside of the Poly-800! Imagine that!

/Mike

On Wed, 2019-01-30 at 12:26 -0600, Synthetech bperkins211@... [korgpolyex] wrote:

I follow you now..

Currently I have control over the parameters via MIDI CCs.
But they will run out fast with all the options I can fit in. Especially if I create a bank of ADSRs for the FM synth.
I was thinking simplifying it down a bit may be better.

What communication did you have in mind between the uC's?

Just last night I got the amp EG working right.
Now I need to make a VCF EG..
I have basic sine wave modulation for VCF, amp and pitch.. need to make ramps and squares.

I will be sure to make another video soon to demo the new features.

Oh... I have been coding this using CubeMx and HAL with that A6 Eclipse ide.
What have you been using?

On Jan 30, 2019 11:58 AM, "support support@... [korgpolyex]" <korgpolyex@yahoogroups.com> wrote:

The board itself is OK for what it needs to do now. Which is to dramatically improve envelopes, sequencer, LFO's, velocity, modulators etc etc.

With that in place, I can add hardware (not to the CPU board) that will be wired in to the main board. Much like the AtomaHawk but a much more powerful board.

This could include a "voice board" that will be modular and allow different options. Your results so far look fantastic, especially as a foundation.

/Mike

On Wed, 2019-01-30 at 10:25 -0600, Synthetech bperkins211@... [korgpolyex] wrote:

Mike, what F4 chip are you using?

A dual DAC I drive uses a I2S port.. It is driven via interrupt triggered DMA.
The bit rate/clock is approx 1.4Mhz for 44.1Khz stereo sample rate.
That DMA works great but it doesn't leave much time between interrupts to do other things.. especially if they are slow processes.

Sounds like you ordered a lot of boards.. Kinda has you locked in for the design?

/Blaine

On Jan 30, 2019 8:44 AM, "support support@... [korgpolyex]" <korgpolyex@yahoogroups.com> wrote:

Hi Blaine,

See the picture. This is the CPU replacement for the Poly-800. I just ordered 100 pieces to begin testing the hardware and writing new software.
The board is based on the STM32F4. Poly-800 owners will have to remove the 80C85 CPU and pop this unit in.

With this installed, there is enormous potential to give the Poly new voices. Much like you said below. We could place new voices before, after or in parallel with the Korg filter.

Clearly, you have done a large amount of the work. And I don't believe in reinventing the wheel. So I would hope that we could come up with some way to integrate our activities in some way.

For one thing, I would like to see if it is feasible to drive a dual D2A via my board. If that is possible, then I could probably reuse most of your code.

On Tue, 2019-01-29 at 17:51 -0600, Synthetech bperkins211@... [korgpolyex] wrote:

Hi Mike,

I would be interested in collaborating with you. Did you have anything in mind or any details?

I am still ironing things out with this.. but I believe in another month or so it will be working much more smoothly.
It's slow going. I only have some evenings and weekends to dive into the coding. I've been learning alot along the way.
It's taken a long time just to study the code to understand it enough to dive in and modify it the way I want it to work.
Every night I mess around with it, it gets a bit better :).
Honestly I didnt think I'd ever get it working, but I just kept at it and very surprised at the results.

It could be possible to use a smaller chip, the F405RG instead of a 407. Get pin size down to 64 instead of 100.

The possibilities can be very interesting. This synth could be mixed in with the Poly's original DCO's and perhaps have a way to selectively run it through the Analog Filter chip.
Of course the built in FX wont be much good if you used them while running it thru the Poly's VCF.
It's also very possible to make a standalone version too.. Could be a side project that people would be interested in.. a cheaper Shruthi.

I just got in the $1.08 16/24bit stereo DACs from DigiKey. I'll have to wait a few weeks for some breakout boards I bought on ChinaEbay to mount/test them.
Unbelievably cheap how much this stuff is now.

I have a ton of ideas, very interested in hearing yours.

/Blaine

On Mon, Jan 28, 2019 at 6:09 PM support support@... [korgpolyex] <korgpolyex@yahoogroups.com> wrote:

Hi Blaine,

it's great work! I am in the process of testing a new board for the Poly-800 that is based on an STM32F4 too! The design doesn't give the Poly any new DCO waveforms so I am very interested in your work and how we could collaborate. I would imagine it would be great to take what you have done and develop it into a board to go into the Poly.

Let me know what you think about that.

/Mike

On Sun, 2019-01-27 at 20:57 -0600, Synthetech bperkins211@... [korgpolyex] wrote:

Hey Mike,

I noticed it's been awful quiet on the yahoogroups. Been busy?

I've been working on and off on this STM32F4 synth chip.
It's been a slow progress, but I think I may have something almost usable here.

Here is a private/unlisted video..

https://youtu.be/Z6L2gvHk7sw

I'm keeping this quiet for now because I'm not sure if I want to share the work I've done so far with the public.

Anyway, take a look and let me know what you think.

/Blaine