err, do also note that the first part of the example given by the person
who answered the question probably is no longer needed. In fact that
application as is would probably fail on modern beaglebone Debian images.
So omit:
fs.open("/sys/kernel/debug/omap_mux/gpmc_ad4");
fs << "7";
fs.close();
As the above code snippet is no longer required. I'm fairly certain
for that step nothing is required to replace it. As universal IO is
enabled by default on all modern
Debian images, and with shell scripts all I've ever had to do was
export the given GPIO pin, to start manipulating it. But if you have
any problems with the example
code in the link i gave above, I'd be able to help sort it out.
Generally though if you google error messages, you should be able to
figure things out on your own.
On Sun, Mar 12, 2017 at 4:38 PM, William Hermans <[email protected]> wrote:
>
>
> On Sun, Mar 12, 2017 at 5:47 AM, Dror Lugasi <[email protected]>
> wrote:
>
>> Hi guys!
>>
>> I am writing a program with C++ for the BBB that has some serial ports
>> and Ethernet communication, and i want to control the GPIO with it.
>>
>> At this moment i am able to activate / read / write / and choose in or
>> out for the digital GPIO, and also read the analog input.
>> I am doing everything with the function "system" that runs a terminal
>> command.
>>
>> I am doing this only cause all the tutorials i saw about GPIO are from
>> the terminal, sending 'echo' and 'cat' to the GPIO's files in the
>> /sys/class/gpio path's..
>>
>>
>> is this a reasonable way? i don't need the GPIO switching to be lightning
>> fast.
>> I saw that there are some libraries (like BlackLib for example) for
>> controlling the GPIO but my question is: does they do exactly that?
>> or do they reach the hardware from a better/faster way??
>>
>> same goes to all other features like PWM, I2C etc...
>>
>> Thanks for your attention!
>>
>
> You need only learn how to read, and write from / to files using C++. Once
> you have that figured out, you just need to learn what files to read from,
> and write to for the desired effect.
>
> One thing to understand, is that the only real advantage of C++ over C in
> this case. Is that C++ has "real" string objects. Instead of C's character
> arrays. So some may argue that C++ is "safer", which to some extent may be
> true. But most of your code will be C. . . and if you pay attention to
> what you're doing. Either language will work fine.
>
> Anyway, if you search the internet with keywords such as "beaglebone GPIO
> in C", then ignore all the mention of libraries. You'll get a good idea of
> how this is done. But you can view the command "cat" as a read, and "echo"
> as a write to a file. So you could adapt command line examples into C or
> C++ just as easily. If you're familiar with either language.
>
> Here is a real C++ example for GPIO on the beaglebone through, using the
> fs object: http://stackoverflow.com/questions/21198933/how-to-
> control-beaglebone-gpio-pins It's not as clean as I like for C, but it's
> true C++.
>
--
For more options, visit http://beagleboard.org/discuss
---
You received this message because you are subscribed to the Google Groups
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/beagleboard/CALHSORpxiaA7QAWED%2B3mqXdjagW1Np9TrYBZqNHvMJtyAsH0qg%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.
