preenfm Forum

PreenFM => preenfm2 and preenfm3 => Topic started by: klangFM on June 26, 2016, 03:30:23 PM

Title: preenFM is going to Eurorack
Post by: klangFM on June 26, 2016, 03:30:23 PM

Finshed my 3HE Eurorack version of this super FM synth.
It is 162mm or 32TE and 40mm deep.
Frontpanel is available in dxf - format on request.
Further info at my site: www. klangbauKöln.de

best
willi

(http://)

Title: Re: preenFM is going to Eurorack
Post by: Xavier on June 27, 2016, 11:23:58 PM

Very nice.. Congrats for your project.

Next step is to add some analogue input usable as source in the matrix  ;)

Xavier

Title: Re: preenFM is going to Eurorack
Post by: klangFM on June 28, 2016, 11:32:58 AM

Fine Xavier,
after you opening a few ports for analog in, I cut associated holes in the frontpanel.
Good idea?

best

willi
www.klangbauköln.de

Title: Re: preenFM is going to Eurorack
Post by: solipsvs on June 30, 2016, 02:25:38 AM

Quote from: Xavier on June 27, 2016, 11:23:58 PM

Very nice.. Congrats for your project.

Next step is to add some analogue input usable as source in the matrix  ;)

Xavier

you wont  :P

but if you do...  there are no words to describe how awesome that could be

Title: Re: preenFM is going to Eurorack
Post by: Xavier on July 03, 2016, 10:04:07 PM

That"s was the P3 connector was for  ;)
But its pins required 0-3.3V input.
I currently need more hours per day.

Could be a good project for a DIY enthusiast. Anyone ?

Title: Re: preenFM is going to Eurorack
Post by: lokki on July 09, 2016, 12:30:25 AM

yep, maybe. so basically we just need to scale the 0-10v control voltage to 0-3.3v and you open the ports and add support for the analog input in the matrix?

this would be super awesome! scaling the cv should not be hard.

Title: Re: preenFM is going to Eurorack
Post by: Xavier on July 09, 2016, 09:23:46 AM

Yes, I've never dug the idea but that's how i see it.
You must add a protection to be sure the voltage never exceed 3.3V or it will damage the MCU.

Xavier

Title: Re: preenFM is going to Eurorack
Post by: lokki on July 09, 2016, 10:45:45 AM

yep. so i will try to come up with something and post the schematic. i will use it with 0-5v signals, but the general principle will be the same.

Title: Re: preenFM is going to Eurorack
Post by: lokki on July 09, 2016, 11:30:32 AM

xavier, how high would the samplerate of the adc with your firmware approximately be? could we also theoretically input audio-rate signals?

cheers

Title: Re: preenFM is going to Eurorack
Post by: Xavier on July 11, 2016, 09:24:10 PM

The Matrix is updated every 32 samples.
No need to read the ADC more often.

Xavier

Title: Re: preenFM is going to Eurorack
Post by: klangFM on February 12, 2017, 04:24:50 PM

Nice to read this.
I is more concret to open the gates for CV in?
It would be nice to open 2 input for 2CV and Gate/Trigger signals to use it in "Matrix".
I don´t know how a Gate could to be implemented. At first it make sense for me.
To scale voltes down to 3,3V I can try it to do.
willi

Title: Re: preenFM is going to Eurorack
Post by: Xavier on February 13, 2017, 12:03:42 AM

I'm away from my computer still for 8 days.
Have a look at this post :
http://ixox.fr/forum/index.php?topic=69235.msg72051#msg72051

Title: Re: preenFM is going to Eurorack
Post by: klangFM on February 15, 2017, 05:39:04 PM

Thanks,
who can compile me this github stuff: acdcIN?
I'am analog.
Question: AD controll range is 0-3.3V. For a scaling opamp one use an inverting desing and output is 3,3V to V.
Therefore it is better to invert input range in acdcIn firmware.
Possible?
As far I get a compiled version I test it and draw a little schematic with board.

willi

Title: Re: preenFM is going to Eurorack
Post by: lokki on February 15, 2017, 09:46:29 PM

i can compile the firmware for you if no one else does :-)

Title: Re: preenFM is going to Eurorack
Post by: lokki on February 15, 2017, 09:57:12 PM

xavier i get this when i try to compile the adc branch:

build/PreenFM_irq.o: In function `TIM2_IRQHandler':
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_irq.c:236: undefined reference to `TIM_ClearITPendingBit'
build/PreenFM_init.o: In function `ADC_Config()':
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:137: undefined reference to `TIM_TimeBaseStructInit'
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:144: undefined reference to `TIM_TimeBaseInit'
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:145: undefined reference to `TIM_SelectOutputTrigger'
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:146: undefined reference to `TIM_ITConfig'
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:167: undefined reference to `DMA_StructInit'
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:186: undefined reference to `DMA_Init'
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:187: undefined reference to `DMA_Cmd'
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:190: undefined reference to `ADC_StructInit'
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:191: undefined reference to `ADC_CommonStructInit'
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:194: undefined reference to `ADC_Cmd'
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:195: undefined reference to `ADC_DeInit'
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:205: undefined reference to `ADC_CommonInit'
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:215: undefined reference to `ADC_Init'
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:219: undefined reference to `ADC_RegularChannelConfig'
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:220: undefined reference to `ADC_RegularChannelConfig'
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:221: undefined reference to `ADC_RegularChannelConfig'
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:222: undefined reference to `ADC_RegularChannelConfig'
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:225: undefined reference to `ADC_DMARequestAfterLastTransferCmd'
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:228: undefined reference to `ADC_DMACmd'
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:231: undefined reference to `ADC_Cmd'
/home/lokki/Downloads/preenfm2-adcIn/src/PreenFM_init.c:234: undefined reference to `TIM_Cmd'
collect2: error: ld returned 1 exit status
Makefile:247: recipe for target 'build/p2_2.06o.elf' failed

Title: Re: preenFM is going to Eurorack
Post by: klangFM on February 17, 2017, 12:23:22 PM

Attached are two possible desings for scaling an anlog input singal to 3,3V with diode protection.
For a 12 bit convertion it should work. It is easy to implement in existing pcb.

Title: Re: preenFM is going to Eurorack
Post by: Xavier on February 19, 2017, 09:35:12 PM

Thanks Lokki for the feedback and klangFM for the schema.
I forgot to push to github the correct Makefile.
It now compiles fine.

I attached the firmware of this adcIn branch.
USE IT AT YOUR OWN RISK !!!  :)

For technical info,  a timer interuption and some DMA mechanism sample automatically the 4 analog pins.
It is done 4 times per block for each analog pins.
The final value is the average of those 4 samples to get rid of sample noise.
The final sampling rate is one value per 32 samples so arround 1200Hz. External oscillator as fast as 500Hz should work, wich leads to modulation much faster than the internal lfo.

I only tested with variable resistor pot plugged between 0v and 3.3v as analog source.
So let me know if some of you succed in using real analog hardware.

Xavier


[attachment deleted by admin]

Title: Re: preenFM is going to Eurorack
Post by: klangFM on February 20, 2017, 02:59:01 PM

Thanks Xavier,
software adcIN  installed and works.
A quick test with hardware scaler on and it works also.
Now test it and play around.
Is it possible to play notes via CV1-FQ and CV2-Gate (routed in matrix)?
At the moment I started to play a note manually or with Midi or running Appegiator.

Title: Re: preenFM is going to Eurorack
Post by: Xavier on February 20, 2017, 09:07:59 PM

Quote from: klangFM on February 20, 2017, 02:59:01 PM

Is it possible to play notes via CV1-FQ and CV2-Gate (routed in matrix)?

No. I know this would be great.
Don't know when i'll find time to do that.

Xavier

Title: Re: preenFM is going to Eurorack
Post by: klangFM on February 20, 2017, 10:35:44 PM

Yes,
but at the moment it is great to have the option of CV in.
Let us explore the possibilities and be happy.
I modify my frontpanel for 4 CVin and make a little pcb for 4CV protection/scalers next days.
The pcb fits on JP3 and needs only few cables.
I keep you informed.

willi

Title: Re: preenFM is going to Eurorack
Post by: Xavier on February 21, 2017, 09:05:02 AM

Quote from: klangFM on February 20, 2017, 10:35:44 PM

I keep you informed.

Thanks  :D
Looking forward to see how it goes... and your modified front panel.

Title: Re: preenFM is going to Eurorack
Post by: klangFM on March 07, 2017, 12:48:44 PM

preefm2 with CV inputs:
At the moment only 2CV in are active. PCB only a prototyp. Later a little pcb will be finished to fit direct on P3, input of ADC.
Input protection works fine:

Title: Re: preenFM is going to Eurorack
Post by: Xavier on March 09, 2017, 02:29:53 PM

 Nice to see the 4 cv in  :)
Thanks for sharing....

Title: Re: preenFM is going to Eurorack
Post by: solipsvs on April 26, 2017, 05:11:29 PM

do want!   :P