Hey TFJ,
I did this way and I would be glad of you helped me in this question. I
have installed Libpruio0.0.2, and I wrote a simple code just to read the
ADC value (Value[1]) from the output port P9_14 to see it commute.(I don't
need all that libraries, but they are there for further algorithms). In the
circuit I added a voltage divider with two 10k resistors, to get about 1,7V
to not cross 1,8V.
-----------------------
/*
Test ADC max sample rate
Libpruio 0.0.2
Compile by:
gcc -Wall -o ReadADC ReadADC.c /usr/local/lib/freebasic/fbrt0.o -lpruio
-L"/usr/local/lib/freebasic/" -lfb -lpthread -lprussdrv -ltermcap -lsupc++
*/
#define _GNU_SOURCE 1
#include "stdio.h"
#include <termios.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/time.h>
#include "../c_wrapper/pruio_c_wrapper.h"
#include "../c_wrapper/pruio_pins.h"
#include <stdlib.h>
#include <stdbool.h>
#include <time.h>
#define P1 P9_14
int main(int argc, char **argv)
{
PruIo *io = pruio_new(0, 0x98, 0 ,1);
pruio_config(io, 0, 0x1FE, 0, 4, 0);
if (io->Errr) {
printf("initialisation failed (%s)\n", io->Errr);}
if (pruio_gpio_set(io, P1, PRUIO_OUT1, PRUIO_LOCK_CHECK)) {
printf("failed setting P1 (%s)\n", io->Errr);}
if (pruio_config(io, 0, 0x1FE, 0, 4, 0)) {
printf("config failed (%s)\n", io->Errr);}
while (1)
{
if (io->Value[1] < 25000 )
{
pruio_gpio_out(io, P1, 1);
printf(" %6d ", io->Value[1]);
printf("\n");
}
else
{
pruio_gpio_out(io, P1, 0);
printf(" %6d ", io->Value[1]);
printf("\n");
}
}
pruio_destroy(io);
return 0;
} // end of main
---------------------
The thing is that I'm only getting about 10kHz. It is normal to just get
this sample rate?
<https://lh3.googleusercontent.com/-uO0ixAS_O6Y/VIbijDNYsYI/AAAAAAAAACE/W42721NvvEU/s1600/20141209_111337.jpg>
Thanks in advance.
Luciano.
Terça-feira, 4 de Novembro de 2014 16:57:48 UTC, TJF escreveu:
>
> Hello jleb!
>
> Sorry for the late answer. I did some testing, meanwhile, and it seems
> that you're right. The ADC subsystem is clocked by CLK_M_OSC directly at 24
> MHz. (First, I thought there's an additionaly pre-scaler in the PRCM.)
>
> Find attached a libpruio measurement from four channels, connected to a
> PWM output by different voltage dividers. The PWM frequency and the
> sampling rate are configured that way that a complete period plus two
> pixels get shown in the window. The result is as expected, and even if I
> increase the frequencies, all looks good up to a sampling rate of 200 kHz.
>
>
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