some help building a library

simonb

Hi there,

I was hoping to experiment with this I2c device and naively thought I would be able to hack the trill examples. But I have realised I probably need to port the adafruit Arduino library over to Bela... And I don't really know what I am doing.

https://learn.adafruit.com/adafruit-tsc2007-i2c-resistive-touch-screen-controller/arduino

I am planning to get the data into supercollider.

I would probably tackle it alone on an Arduino but on Bela I usually use the lovely web interface and I don't even know where the libraries live, how to create one etc.

I am sure it's trivial for others here so if anyone can point me in the right direction that would be great. I would also be open to paying for someone for help port a library over / or do an online tutorial as this is the sort of thing that will likely confuse me for days.

Many thanks

Simon

simonb

So I watched this from its 4 years ago but it suggests that you can't make your own Bela libraries. Is that still the case

Sorry for the questions.. I am just new to this and used to Teensy, and Arduino where the library code is easy to grab and mess with.

Many thanks
Simon

giuliomoro

it suggests that you can't make your own Bela libraries. Is that still the case

Well, you can. These "libraries" on Bela are reusable classes that you can use in your C++ projects. We don't have a great workflow, but you can indeed write them and add them in. If out of this project came a usable library for this resistive display, I would be very happy to help you integrating it.

Writing Supercollider ugens is kind of complicated and neither Trill nor your display would strictly need one, because you don't need to process audio in these ugens. A better approach that is easier to code and can be used from any programming language can be to have a device-OSC bridge that can run as a stand-alone program on the side of your audio processing program and that you can send or receive OSC from. There are a number of examples doing just this:

OSC to OLED https://github.com/giuliomoro/O2O
OSC to Neopixels https://github.com/giuliomoro/O2L
OSC to/from Trill https://github.com/BelaPlatform/Trill-Linux/tree/master/examples/trill-osc

Once you have such a program, you can run it as a service as explained here https://learn.bela.io/using-bela/bela-techniques/running-a-program-as-a-service/ .

Now, for your specific application, we could have a multi-step approach:

write a standalone program that doesn't do any audio processing but manages to connect to the screen, reads from it and prints to console
have it send OSC
run it as a service

Now for step 1, I was coincidentally planning on doing some work on adding a compatibility layer for Wire and/or the Adafruit I2C library, so I could do it that way (slower) or just make it work (faster). It's going to be fun either way because I don't have the device.

simonb

Hi giuliomoro,

Thanks so much for that detailed reply. Makes total sense. I am happy to send you a display and the adafruit driver display. Honestly I would rather mess around with the supercollider sound making bit. You could mail me on simon@simonblackmore.net and we could take that further. I am also looking at another adafruit driver that outputs serial and that is probably easier for me to implement if I were to go it alone. But they seem to be stopping producing that one.

https://www.adafruit.com/product/1580

Many thanks

Simon

giuliomoro

simonb I am happy to send you a display and the adafruit driver display.

Thanks, hopefully that won't be necessary.

write a standalone program that doesn't do any audio processing but manages to connect to the screen, reads from it and prints to console

This should build as a project on your Bela board (you can download this as a zip archive, drop it on the IDE and use the ensuing dialog to create a project off of it). It expects you to connect the device to the I2C1 bus (the pins highlights as I2C in the pin diagram for your board).

Give it a try and let me know if it displays any results with your sensor.

simonb

Ah ok cool... That sounds doable. I just can't get my head around the IDE at the moments. So if I make a new project I get render .cpp file and a Bela.h file which I can't access.

Don't I need to be able to access the header file and include libraries like...

#include <linux/i2c.h>

Do you mean I just grab something like the "printing to the console" example and add to it until I get data from the I2C bus.. not worry about the header file.

like this.....

#include <Bela.h>
#include <cmath>
#include <linux/i2c.h>

float gInterval = 0.5;
float gSecondsElapsed = 0;
int gCount = 0;

bool setup(BelaContext *context, void *userData)
{
 // Write a command byte to the TSC2007 and read the 2-byte response

// look at how you are handling this stuff in the trill library

    // Print a string
	rt_printf("This Bela example has just started running!\n");
	// after loads of coffee and hacking about
    rt_printf("the data from the screen magically appears and then I work on sending it as osc");

	return true;
}

Thanks again for the help.

giuliomoro

simonb Do you mean I just grab something like the "printing to the console" example and add to it until I get data from the I2C bus.. not worry about the header file.

No, I mean literally just putting that code in a project exactly the way it is. Download it as a zip archive from github, drag the archive on top of the IDE, follow the instructions in the dialog to create the project from it and execute it as it is. As it contains a main() function, it will execute that and not any of the "Bela" stuff that normally happens in the background.

simonb

I mean literally just putting that code in a project exactly the way it is.

Sorry for the confusion.. but what code? the examples you sent?

so make a new project,

download
OSC to/from Trill https://github.com/BelaPlatform/Trill-Linux/tree/master/examples/trill-osc

Drop that in the project

Then edit it until I get some results?

That sets up all the back end stuff I need?

Thanks

simonb

Ok I think I get what you mean...

I read through this...
https://learn.bela.io/using-bela/bela-techniques/using-an-oled-screen/

Downloaded the zip.... (which my Mac seems to automatically unzip so I have to zip it again.)

I drop that into Bela and get access to all the files. and it looks like this. And I can build it from there.

Is that right? What's the best project to clone as a starting point?

Cheers

Simon

giuliomoro

Oh I see why you were confused: I didn't post the link to the rep I worked on.
Here it is: https://github.com/giuliomoro/Adafruit_TSC2007-Linux

simonb

Oh wow magic!.... Did you you just knock that up? amazing. Right that looks like a good start.

Thanks!

simonb

So, dropped it in and it runs which I am seeing as a small victory.

Unfortunately saying...

"Bela: Couldn't find touch controller"

sensor lights are on and 99.9% all connections are good so just checking through.

Thanks again

giuliomoro

Can you show your wiring? Also, that assumes that the device is using its default address of 0x48. Also, with the sensor connected run in the console at the bottom of the IDE:

i2cdetect -y -r 1

and show the result here

simonb

Cool thanks so much. OK two pics. I think it's using the default address.

giuliomoro

ok I amended the repo, get the updated version and try again.

simonb

That works.... Amazing thanks so much. So now I just need to figure out how to send it out via OSC to SC. What's the best approach there?

giuliomoro

OK I updated the repo so that it sends to localhost:1234 an OSC message to address /tsc containing four integers with the values you were previously seeing printed. For prototyping purposes , you may want it to send to the host computer instead, in which case replace "hostAddress = localhost" with "hostAddres = 192.168.7.1" (or 192.168.6.1, depending on what address your computer has on the point-to-point network with Bela), also adjust the port number to taste.

I can receive this with this simple Pd patch, surely it's easy enough to do in Supercollider as well:

If this works as expected, then use the instructions here https://learn.bela.io/using-bela/bela-techniques/running-a-program-as-a-service/ to run it in the background while you run a proper Bela program on the side.

simonb

That's great...thanks.
Something going wrong on my end though.

giuliomoro

can you update the code on your Bela to the latest dev branch and then try again? This is done downloading this archive https://github.com/BelaPlatform/Bela/archive/refs/heads/dev.zip and uploading it on the IDE via the "Update Bela" button in the settings tab as per this image:

simonb

Wow you are amazing... looks like it's working. The running as a service looks well documented so will try that later.

Do you have one of those buy me a coffee type things?

Thanks!!

giuliomoro

simonb Bela’s audio, analog and digital I/Os

these are all handled by a "Bela program" and there can only be one of these running at any time, which will take control over all of those, processing them at audio sampling rate and with low latency. "digital I/O" here refers to the 16 GPIOs handled directly by the Bela core, which are those highlighted in the pin diagram for your board. This does not include devices connected over other digital busses e.g.: I2C, UART, SPI, which can he handled by any program running on the board. You can still access the GPIOs that are not managed by Bela and are not otherwise used by Bela using the Gpio class and integrating it within this same program. See more details here.

simonb I was just think how cool this is and setting it up this project to read a few analog inputs/switches and then just having SuperCollider receiving OSC and making sound.

If you are processing audio via scsynth, you'll have to process all of those also via scsynth, there are dedicated ugens to do that: AnalogIn, DigitalIn, DigitalOut, DigitalIO. You can then use sendReply() if you want to send a snapshot of the input values back to sclang.

simonb Do you have one of those buy me a coffee type things?

No thanks, I don't drink coffee. Just tell all your friends about the good experience you've had here.