Hi,

I am planning a rather ambitious project and just have a question about whether or not what I am planning to do is possible. I apologize if these are basic questions.

Basically, I am working on a Pure Data project, some kind of groovebox with a sequencer.
The part that is still unclear is how to get my Pure Data patch visualized on an OLED screen.

I was considering a combination of a Raspberry Pi and PiSound, or Bela.
So far, I actually prefer Bela, as it already has a good tutorial on how to connect an OLED and communicate with OSC.

Initially, I thought I would be able to display the actual Pure Data interface or GOP (Graph on Parent) on the display, but that doesn't seem to be possible. Even on mobile phones with the Pure Data Android app, it seems to work well.

It looks like the only option is OSC, even though I don't fully understand how it works. From what I understand, it just sends messages and doesn't include graphical elements.

What other options do I have to actually send graphics like dials and sliders to an OLED, rather than just text messages? I have very limited programming skills. Pure Data is fine, and I can figure that out, but C++ is a different story.

Also, is there a way to emulate or test how OSC messages will be received if I were to use an OLED screen?

That's rather ambitious indeed. I don't believe you'll be able to display the actual patch. Even if you want to only display knobs and other widgets, you'll have to code this interface yourself and control Pd, or have Pd control those, by sending values for these widgets via OSC.
If I understand what you describe, you want to create a graphical user interface to control a Pd patch, right? If this is so, then what I wrote about holds.
You could try to find some library (it would probably be Python or C++) that creates widgets for OLED displays, and use that together with OSC, but the API you'll use should support OSC communication.

@impression As I said in your other thread, if you use an OLED which has a frame buffer driver for it you will be fine, you just need to load the driver and it will act like a normal display. Here is one for the pi: https://github.com/foldedtoad/raspberry-pi-oled but if you can find an OLED that uses the same chip or one of the others that driver supports and a normal I2C interface instead of the pi bonnet it will probably work just fine with bela. There are probably others but that is just the first I found, did not dig. Could also make the pi bonnet work withh bela without much work, just would have to connect it with wires/jumpers instead of plugging it right in like you can on the pi.

Why do you only have OSC? Just assuming that based off of the OLED you found or something else?

From what I understand, OSC is basically used for transferring messages from Pure Data to the OLED. That's the only information I could find on the Bela website, and it seems like the only way to communicate with the screen.

My main question is, what options do I have for creating a visual representation of what I'm doing in Pure Data if I am not able to use the actual Pure Data GUI? I would love to avoid Python or C++, but it almost seems like there's no way around it. Even then, I don't fully understand how things connect properly. The reason I am asking, if showing the Pure Data GUI is not the right way to go, then I don't really need to waste time making a nice Pure Data GUI in the first place.

Let’s say I programmed a dial in C++; would it essentially need to receive the OSC message from Pure Data and send it to the screen? And how does I2C come into play?

If I have an OLED with a framebuffer driver, would I be able to show the actual Pure Data GUI? I assume that also would to be communicated somehow? If I run a pure data patch on Bela I am not sure if its meant to show the actual GUI in the first place.

I’m really sorry if these are beginner questions, but your help is greatly appreciated. I'm very new to this, and I don’t quite see the whole picture yet in terms of how everything works together. The screen part seems my biggest question mark so far for my project.

OSC is not used by the screen but by the Bela board which interprets it and communicates to the OLED by the u8g2 Arduino library throw the I2C protocol.

The graphics for each OSC message types are defined here https://github.com/giuliomoro/O2O/blob/main/main.cpp so you can add/modify to your need.

You can also drive the OLED directly from the RPi with the same library, see https://github.com/ribasco/u8g2-rpi-demo.

@impression On Bela it is more difficult to use a frame buffer and those sorts of graphics but it is a BeagleBone running linux so you can do it but they probably will not offer much help in how to do it, they seem to try and keep Bela using just the Bela products, they don't want to have to try and offer support for the massive amount of third party peripherals out there and I don't blame them for that. On a pi if you use an OLED which there is a frame buffer driver for it will act like a normal computer screen once the driver has been loaded, the OS/kernel will handle all the details of how to draw stuff to the screen for you, it will draw your desktop when you startup and when you open pd it will draw pd.

I would recommend just getting one of those cheap pis and using it for a simpler project to get your feet wet and learn and get all your beginner mistakes out of the way before diving into the big ambitious project, it will most likely be quicker in the long run. Get a couple of the adafruit quad rotary encoder boards and some buttons/pads, make yourself a simple 303 style bass synth, use the onboard sound and you can probably manage it for $50 total with most parts (if not all) being able to be reused for your big project when the time comes if you want to save money and are willing to sacrifice your first born.

yea. I thought Bela sounded like the better setup, connecting buttons and encoders seems much easier, plus I wouldn`t have any latency issues.
But I probably follow your advice and try it with the raspberry pi first. Its probably also more flexible overall. pisound might get rid of my latency issues as well.

Thanks so much again for all your help