FM VCO with Arduino (Hagiwo)

[BenForzato]

Hey guys, bloody amateur here…

I am so impressed by the work from all of you! Here are so many genius musicians and DIYers, that i feel a little bit uncormfortable asking you this profane question. But i don’t know anyone else who could help me:

I already made a little set of analog modules that sound quite juicy. However, I just can not wrap my coconut of a head around copying and pasting a damn Arduino Source code and getting this module to work! I don’t understand what is going on, but i seem to kill all of my arduinos in this project.
Sometimes, i can’t even plug in a USB cable without the arduino either not reacting or buzzing and smelling like burnt toe nails. One time, I was finally able to get a message of a succesfull transfer, but after I connected it to the 12V, the same BS happened again… Maybe it touched a part, that it should not or i made a bad Stripboard Layout. So here it is, maybe you find proof for my stupidity.

P.S.: My english lessons in school have been a few years, sorry for that. But i think you’ll understand what i mean;)

[OneLove]

Hey, is your arduino soldered to the board? I watched Sam’s arduino keyboard and sequencer videos this evening and he said something like; ‘the ‘RX’ pin is used by the usb when uploading code so you need to remove it from the circuit to do that’ i think he mentioned it could damage the board also.
Kind regards,

[BenForzato]

Firstly, thanks for answering!
But no, I didn’t solder the RX pin to the board (I didn’t solder the 6-pin thingy at all). I also tried so only solder those points to the board, that are necessary for the cirtuit and partly cut the connection on the board itself, even if it wasn’t even necessary (for safety).

[sentient-machines]

Did you get this working on a breadboard first?

Is there a reason you’re supplying the arduino with 12v instead of 5v? Is your 12v supply putting out exactly 12.0v?

These aren’t rhetorical questions, I’m just brainstorming

[analogoutput]

You can put 7–12 V on the VIN pin, it’s fine. It gets regulated down to 5 V on board. If you want to power a Nano with an external regulated 5 V supply it needs to go to the 5V pin.

[sebastian]

Has anyone compared these two kinds of powering? Like is one of them saving a bit of power? or makes more or less noise?

[klausklaerwerk]

seems you are shorting 5V to GND.
see the encircled bit, goes to GND via the black wire below the Arduino.

[BenForzato]

Thanks! That really helped in the first place! But actually, i seem to have f*****d up somewhere else too. I promise, I didn’t solder that bad!
Could it be, that I used the wrong formular to combine capacitors, because I don’t have one with 4,7uF?

I’ve put them in parallel (right term?)… And I don’t know if this could cause any problems in the circuit, because it’s just part of the output circuitury.

Btw. I did cut the copper traces where I’ve put the stuff right next to the arduino. And after that picture was made, I connected everything important with cables (expecially the output circuitury).

[analogoutput]

General advice for troubleshooting a module and asking for help

(This is a wiki post, please add and correct!) Look and see if others have had the same problem. Use the Discourse search facility to find topics where the module you’re building is discussed. Inspect your work. Verify all components are correct values. Look for solder connections that are rough, irregular, skimpy, dull, or missed completely (we all do that!) and reflow them. Look for solder bridges between pads and remove them. Check your power connection. If it’s a Eurorack style power cabl…

[Spocky007]

Am i right in saying the Mozzi library isn’t part of Hagiwo’s code?

I’m having a go at building this and have started a stripboard layout (my first ever)

How easy is it to add the Mozzi library to the code?

[Dud]

You need to import the library, look here

Installing Libraries | Arduino Documentation

[Spocky007]

Thank you Dud, so once the library is loaded the Hagiwo code will take care of everything?

[Dud]

Yes everything should work

[Spocky007]

Just to clarify on this point for me, are the TL07x op amps suitable? Looking at the data sheat the maximum output voltage swing is ± 12 V. Am i looking at the correct characteristic on the datesheet?

[analogoutput]

See above:

@fredrik

I guess I should have looked at the schematics before posting that comment , because it turns out the opamp is only used to buffer the filtered dual PWM output , so if you have ±12 V you can power the opamp with that and use pretty much anything.

@HAGIWO wanted to use +5 V power so needed something like the NJM2732 to get output swing 0–5 V. But that requirement isn’t relevant if you use ±12 V.

@Spocky007

Looking at the data sheat the maximum output voltage swing is ± 12 V.

That’s with ±15 V power. With ±12 V it’s more like ±10.5 V swing, but all you need is 0 to +5.

[Spocky007]

That all makes sense, thank you!

[cwrigh13]

I just finished building this and can confirm that an LM358 works perfectly fine.

[cwrigh13]

You’ll need to download the Mozzi library and install it in your Arduino IDE. Then copy and paste the code from Hagiwo’s blog into your Arduino IDE (Hagiwo’s sketch won’t work without the Mozzi library). Hope this helps!