How to use digitalRead() + Examples of Pepper usage on C++

eluke309

I am trying to use Pepper to run some C++ code.

When I try to use digitalWrite(): 15, to use the left button - as specified in https://github.com/BelaPlatform/bela-pepper/wiki/Pin-numbering), I get the following error:

no matching function for call to 'digitalWrite' column: 20, line: 6

this is my code:

#include <Bela.h>

bool setup(BelaContext *context, void *userData)
{
	bool leftButton = digitalWrite(): 14;
	return true;
}

void render(BelaContext *context, void *userData)
{
}

void cleanup(BelaContext *context, void *userData)
{
}

Am I missing something?

Also: I can not find any examples of Pepper code in C++ - I think a few of these could be quite helpful : )

giuliomoro

eluke309 bool leftButton = digitalWrite(): 14;

this is not valid C++ syntax. The arguments need to go inside the parentheses. digitalWrite() or digitalRead() take more arguments than just a pin number. The notation function_name() in the documentation is a convention to indicate that we are talking about a function - as opposed to e.g.: a variable, and it is not to suggest that the function takes no arguments. Full documentation for this class of functions is here.

You probably mean digitalRead() anyhow. Keep in mind that reading / writing from within setup() won't return actual values, you need to do that from within render().

eluke309 Also: I can not find any examples of Pepper code in C++ - I think a few of these could be quite helpful : )

All the non-Pepper examples will also work on Pepper, as long as you use the appropriate pins as per the page you linked and so there is plenty of C++ examples right there. The Pepper examples are ready-to-go Eurorack patches. We have a full C++ course dedicated to Bela which applies just as well to Pepper:

eluke309

Thanks a lot for your reply! I have managed to get analog reads/writes from all I/Os after watching that one video.

I still have one doubt though. After extending the analog scope example to include all inputs (I changed the jumpers in the back to analog), I notice the 4 last inputs (4, 5, 6, 7) do not show a voltage reading unless voltage is plugged in.

The potentiometers do what they are supposed to and attenuate any signal going trough those inputs, but when nothing is plugged, the inputs read 0V.

Does this have anything to do with the jumper wires?

Thank you

eluke309

Instantly after posting I realized I actually had not connected the horizontal jumper wires. Everything is good now, thank you.