AM3358: ADC issue in C program

Hello Alan,

This sounds like a generic Linux question rather than a TI-specific question. (How do I take something I type into the terminal, and put it in a script instead?). We only support TI-specific questions on the forum (e.g., how do I use the ADC driver? did I connect up my ADC wrong? etc). I suggest searching around on Google to find your answer.

Feel free to reply if you disagree and we can continue the discussion.

Regards,

Nick

Hello Alan,

Here is the C code I tested. I used open, read, close commands. There are probably some unneeded includes, I just threw the example together. It works as expected on AM65x ADC, but AM335x has the same ADC so it should work just fine on BeagleBone Black.

Regards,

Nick

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <stdbool.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdbool.h>
#include <poll.h>
#include <inttypes.h>
#include <unistd.h>
#include <errno.h>

/* 4 digits are sufficient to read ADC raw values */
/* chose a bigger number just in case */
#define BUF_SIZE 10
char payload[BUF_SIZE];

int main(int argc, char *argv[])
{
        /* create output file descriptor */
        int output_fd;
        char adcName[] = "/sys/bus/iio/devices/iio\:device0/in_voltage0_raw";
        output_fd = open(adcName, O_RDWR);
        if (output_fd < 0) {
                printf("failed to open ADC");
                exit(EXIT_FAILURE);
        }

        /* read ADC voltage */
        int readResult = read(output_fd, payload, BUF_SIZE);
        printf("ADC output is %s \n",payload);

        close(output_fd);

        return EXIT_SUCCESS;
}