Ok thank you for going to the effort.
I may have a go at the stripboard layout posted above.
Thanks again.
Dear Mr. Analog Output
First of all, I’m new to this platform so I’m not sure if my post is in the correct topic. So excuse me for this when it’s not.
Ok, to keep things tidy and short I was wondering if someone would be willing to help me with the MCVI module that I’ve build over the last couple of days. Its works for the most part and I only need the two CLOCK outputs to work. For some reason it does not. in the mcvi.ino file everything looks fine to me (i can read and understand most part of the programming) but CLOCK_1PQ on pin D4 and CLOCK_4PQ on pin D5 is not working. The LED’s are not blinking, nor a voltage is measured with the multimeter. So i tested all digital pin’s via the ‘BLINK’ code to see if these pin’s are defect, but then it works. So electrically everything seems in order. I’ve triple checked the wiring etc, etc. I’m not new to DIY Synth build but still it’s possible that i have missed something. Is there someone who could point me in the right direction? or maybe share the mcvi.ino file with me? Please let me know if you need more information. I’m using an Arduino Nano (atmega328p). Thanks in advance for your help.
kind regards
Marty
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If everything works as it should expect the clock, are you sure that you actually send clock information through MIDI ?
Hi Bpbby
First of all, thanks for the reply…
As far as i understood, the Arduino Nano handles the clock based on the midi input? But i am not sure. I see the SMD Led’s on the arduino flashing very fast meaning that midi information is coming in. I use the midi output of my Yamaha DX7 synth connected to the module. Should i check on the DX7 if clock messages are being sent? Will check that later. Thanks
Yes, it takes the MIDI clock and divides it down to 1 and 4 per quarter note. If there’s no MIDI clock in, there’s no clock pulses out.
Not sure what you mean by that, you should have that file from the repo, it’s what you upload to the Nano to make it work.
You should be able to use this to check what MIDI messages you have, if you can’t find out through documentation or whatever:
Hi Mr Holmes.
Thanks for your reply, really appreciate it. Makes sense ofcourse. No input, no output. Didn’t know that the midi clock pulses are from external source. The Nano will then divide it. I do understand now. Kind regards
Marty
Hi Mr. Holmes
Just want to let you know that everything works as you intended. The misunderstanding was obviously on my side. I hooked up my DAW midi out to the midi input, and the LED pulses started to flash. Super. Thanks again for the help
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Hi Mr. Holmes
May i kindly ask for your help once more?
Im trying to change the code so it works for 5 octaves. I have a 61 key synth and don’t need 88 notes.
I saw in the code something like bottomnote and topnote. So i changed 88 (midi note 108) to 61 (midi note 84) as topnotes and bottomnote 21 (A0) to 24 (C1). I calculated 4095/60 instead of 87, and changed the note_sf line in the code. When i try listening to it, I still hear very low and high pitched sound but with bigger note gaps in between. No obviously i did something wrong.
Can you please help me what lines in de code i need to change to get 5 octaves over 61 keys?
Thanks again do much for your help
Kind regards
Marty
It’s basically not my code, so it’d take some study to figure that out.
But I don’t see why there is a need to do this. It should work just fine with a 61 key synth. Just that 27 notes will never be sent to it and be processed.
If for some reason you really want to enforce not converting notes 21–23 and 85–108 you could just add a couple lines to the code to test for those values and ignore them.
Hi Rich
Thanks again for your reply.
The code should cope with a 61 key keybed as long as the note numbers it outputs fall within the range the converter is designed to work in. This I think is Elkyam code which I have used extensively in several designs. Using the MCP4822 at 0.5v per octave and doubling it at the converter should allow for approx 10 octaves using a 5v supply.
What you have got to be care of is where 0v is generated by the DAC, anything below that is basically ignored so it’s a trade off, midi notes are 0-127 or c-2 to c10 approx and c-2 should be in reality 0v, but in practice this is not possible as a 5 octave keyboard probably puts out c1 to c6 with transpose of 1 to 2 octaves either side. So your bottom c might be note 36 which should put out 3v on a midi to CV converter, now you probably don’t want that fir your VCOs, maybe you want 0-5v not 3-8v. So in the code you can generate 0v at c3 and 5v at c8, this gives you another problem in that - transpose no longer works as your dac is already at 0v on bottom c.
In these things it’s always a trade off unless you have a dav that can swing +/-v from 0 and then you can have a true midi to CV converter as your VCOs should be able to cope with +/- CV voltages, but in this design and many others (including my own) you are limited to +ve voltages only, even the pitch bend output is centered around 1v to allow it to swing from 0v to 2v. Not ideal but at least it works, ideally it should centered at 0v and swing +/- 1v.
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Hi Craigyb,
Everything works like a charm now. Sorry for the late response.
Regards
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