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@ric96 ric96/main.c
Created Dec 3, 2017

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hcsr04 sample code for zephyr on 96b_carbon
#include <zephyr.h>
#include <misc/printk.h>
#include <device.h>
#include <gpio.h>
#include <sys_clock.h>
#include <misc/util.h>
#include <limits.h>
#define GPIO_OUT_PIN 1
#define GPIO_INT_PIN 3
#define PORT "GPIOA"
void main(void)
{
uint32_t cycles_spent;
uint32_t nanseconds_spent;
uint32_t val;
uint32_t cm;
uint32_t stop_time;
uint32_t start_time;
struct device *dev;
dev = device_get_binding(PORT);
gpio_pin_configure(dev, GPIO_OUT_PIN, GPIO_DIR_OUT);
gpio_pin_configure(dev, GPIO_INT_PIN, (GPIO_DIR_IN | GPIO_INT_EDGE| GPIO_INT_ACTIVE_HIGH | GPIO_INT_DEBOUNCE));
while (1) {
gpio_pin_write(dev, GPIO_OUT_PIN, 1);
k_sleep(K_MSEC(10));
gpio_pin_write(dev, GPIO_OUT_PIN, 0);
do {
gpio_pin_read(dev, GPIO_INT_PIN, &val);
} while (val == 0);
start_time = k_cycle_get_32();
do {
gpio_pin_read(dev, GPIO_INT_PIN, &val);
stop_time = k_cycle_get_32();
cycles_spent = stop_time - start_time;
if (cycles_spent > 1266720) //260cm for 84MHz (((MAX_RANGE * 58000) / 1000000000) * (CLOCK * 1000000))
{
break;
}
} while (val == 1);
nanseconds_spent = SYS_CLOCK_HW_CYCLES_TO_NS(cycles_spent);
cm = nanseconds_spent / 58000;
printk("%d\n", cm);
k_sleep(100);
}
}
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