[MinnowBoard] GPIO doesn't working as Input

[Jesus Velazquez]

Hi Van,

I'm runnig my programs with root privileges and this is the
/var/log/messages output:

--
2017-07-12T19:10:32.808475-04:00 blackbox libmraa[4112]: libmraa version
v1.5.1 initialised by user 'root' with EUID 0
2017-07-12T19:10:32.812676-04:00 blackbox libmraa[4112]: libmraa
initialised for platform 'MinnowBoard MAX' of type 4

--

After that, anymore messages is shown

Any other suggerence?


2017-07-12 14:45 GMT-05:00 Van Der Pol, MarkX <markx.van.der.pol at intel.com>:

> Hi Jesus,
>
>
>
> The GPIO pins on the Turbot are functional, so I am surprised you are
> having such issues.
>
>
>
> One thing that comes to mind is that the MRAA libraries are expecting to
> have root privileges, so make sure you either execute you program with a
> ‘sudo’ context ( as in, if your program is called ‘test_gpio’, you execute
> ‘sudo test_gpio’ to elevate the program to run with root permissions), or
> log in as root.
>
>
>
> You can also examine the syslog messages to see what MRAA is reporting
> –certain MRAA error conditions logged there. For instance on Ubuntu ‘cat
> /var/log/syslog’ to see the whole log.
>
>
>
> Hope that helps,
>
> |\/|ark
>
>
>
> *From:* elinux-MinnowBoard [mailto:elinux-minnowboard-
> bounces at lists.elinux.org] *On Behalf Of *Jesus Velazquez
> *Sent:* Thursday, July 6, 2017 2:51 PM
> *To:* MinnowBoard Community Email List <elinux-minnowboard at lists.
> elinux.org>
> *Subject:* Re: [MinnowBoard] GPIO doesn't working as Input
>
>
>
> Hi Van,
>
>
>
> I have Ubuntu 16.04 with kernel version:
>
>
>
> Linux blackbox 4.4.0-81-generic #104-Ubuntu SMP Wed Jun 14 08:17:06 UTC
> 2017 x86_64 x86_64 x86_64 GNU/Linux
>
>
>
> And I has have test with Pulsar Linux 7 with kernel 3.18.x
>
>
>
> My libraries that I use is MRAA Version: v1.7.0-44-gbd3d9d8 ( https://
> iotdk.intel.com/docs/master/mraa/ )
>
>
>
> I have tried with Pins 26, 25, 21, 20 and 14.
>
>
>
> This is my code:
>
>
>
> ---
>
> #include "mraa/gpio.h"
>
>
>
> int main(){
>
>    /* initialize MRAA */
>
>    mraa_init();
>
>
>
>    /* create an MRAA digital context */
>
>    mraa_gpio_context m_gpio = NULL;
>
>
>
>    /* initialize D2 for use as a digital pin */
>
>    m_gpio = mraa_gpio_init(26);
>
>
>
>    /* configure the digital pin as an input */
>
>    mraa_gpio_dir(m_gpio, MRAA_GPIO_IN);
>
>    /* Set Gpio input mode */
>
>    mraa_gpio_input_mode(m_gpio, MRAA_GPIO_ACTIVE_LOW);
>
>
>
>    /* read the value into an integer */
>
>    int value = mraa_gpio_read(m_gpio);
>
>
>
>    /* print the value */
>
>    if (value != 0)
>
>       printf("The button is being pushed %d\n", value);
>
>    else
>
>      printf("The button is not being pushed %d\n", value);
>
>
>
>    /* now release (close) the pin and exit */
>
>    mraa_gpio_close(m_gpio);
>
>    return(0);
>
> }
>
>
>
> ---
>
> Thank you for your help
>
>
>
> Jesus V
>
>
>
>
>
>
>
> 2017-07-06 14:42 GMT-05:00 Van Der Pol, MarkX <markx.van.der.pol at intel.com
> >:
>
> Hi Jesus,
>
> Welcome to the list.
>
>
>
> Please let me know the OS and libraries you are using to access the GPIO
> pin in question, and what program you use to test the GPIO state.
>
>
>
> And is it specifically GPIO 26, or are all GPIO’s behaving this way?
>
>
>
> Thanks,
>
> |\/|ark
>
>
>
> *From:* elinux-MinnowBoard [mailto:elinux-minnowboard-
> bounces at lists.elinux.org] *On Behalf Of *Jesus Velazquez
> *Sent:* Wednesday, July 5, 2017 9:14 AM
> *To:* elinux-minnowboard at lists.elinux.org
> *Subject:* [MinnowBoard] GPIO doesn't working as Input
>
>
>
> Hello list,
>
>
>
> This is my first post in this list and I'm happy for join me to it.
>
>
>
> I have a Minnowboard Turbot and I would like to manage a GPIO as input but
> I can see that my pin (26 for example) always is in HIGH state and the
> interruption never is active.
>
>
>
> If I use the GPIO as output, it works fine and can change the state, but
> as Input not.
>
>
>
> Somebody have the same experience? or can resolve this issue?
>
>
>
> Thanks in advance.
>
>
>
>
>
>
> _______________________________________________
> elinux-MinnowBoard mailing list
> elinux-MinnowBoard at lists.elinux.org
> http://lists.elinux.org/mailman/listinfo/elinux-minnowboard
>
>
>
> _______________________________________________
> elinux-MinnowBoard mailing list
> elinux-MinnowBoard at lists.elinux.org
> http://lists.elinux.org/mailman/listinfo/elinux-minnowboard
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.elinux.org/pipermail/elinux-minnowboard/attachments/20170712/049cd052/attachment-0001.html>