Merge pull request #235 from UncleRus/extras/ultrasonic

Driver for ultrasonic range meters + example
This commit is contained in:
sheinz 2016-10-13 00:50:55 +03:00 committed by GitHub
commit 0a8c61ffb7
5 changed files with 179 additions and 0 deletions

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PROGRAM = ultrasonic
EXTRA_COMPONENTS = extras/ultrasonic
include ../../common.mk

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/*
* Example of using ultrasonic rnaghe meter like HC-SR04
*
* Part of esp-open-rtos
* Copyright (C) 2016 Ruslan V. Uss <unclerus@gmail.com>
* BSD Licensed as described in the file LICENSE
*/
#include <espressif/esp_common.h>
#include <esp/uart.h>
#include <esp/gpio.h>
#include <ultrasonic/ultrasonic.h>
#define TRIGGER_PIN 5
#define ECHO_PIN 4
#define MAX_DISTANCE_CM 500 // 5m max
void delay_ms(uint32_t ms)
{
for (uint32_t i = 0; i < ms; i ++)
sdk_os_delay_us(1000);
}
void user_init()
{
uart_set_baud(0, 115200);
printf("SDK version : %s\n", sdk_system_get_sdk_version());
ultrasonic_sensor_t sensor = {
.trigger_pin = TRIGGER_PIN,
.echo_pin = ECHO_PIN
};
ultrasoinc_init(&sensor);
while (true)
{
int32_t distance = ultrasoinc_measure_cm(&sensor, MAX_DISTANCE_CM);
if (distance < 0)
{
printf("Error: ");
switch (distance)
{
case ULTRASONIC_ERROR_PING:
printf("Cannot ping (device is in invalid state)\n");
break;
case ULTRASONIC_ERROR_PING_TIMEOUT:
printf("Ping timeout (no device found)\n");
break;
case ULTRASONIC_ERROR_ECHO_TIMEOUT:
printf("Echo timeout (i.e. distance too big)\n");
break;
}
}
else
printf("Distance: %d cm, %.02f m\n", distance, distance / 100.0);
delay_ms(200);
}
}

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# Component makefile for extras/ultrasonic
# expected anyone using this driver includes it as 'ultrasonic/ultrasonic.h'
INC_DIRS += $(ultrasonic_ROOT)..
# args for passing into compile rule generation
ultrasonic_SRC_DIR = $(ultrasonic_ROOT)
$(eval $(call component_compile_rules,ultrasonic))

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/*
* Driver for ultrasonic range meters, e.g. HC-SR04, HY-SRF05 and so on
*
* Part of esp-open-rtos
* Copyright (C) 2016 Ruslan V. Uss <unclerus@gmail.com>
* BSD Licensed as described in the file LICENSE
*/
#include "ultrasonic.h"
#include <esp/gpio.h>
#include <espressif/esp_common.h>
#include <stdio.h>
#define TRIGGER_LOW_DELAY 4
#define TRIGGER_HIGH_DELAY 10
#define PING_TIMEOUT 6000
#define ROUNDTRIP 58
void ultrasoinc_init(const ultrasonic_sensor_t *dev)
{
gpio_enable(dev->trigger_pin, GPIO_OUTPUT);
gpio_enable(dev->echo_pin, GPIO_INPUT);
gpio_write(dev->trigger_pin, false);
}
int32_t ultrasoinc_measure_cm(const ultrasonic_sensor_t *dev, uint32_t max_distance)
{
// Ping: Low for 2..4 us, then high 10 us
gpio_write(dev->trigger_pin, false);
sdk_os_delay_us(TRIGGER_LOW_DELAY);
gpio_write(dev->trigger_pin, true);
sdk_os_delay_us(TRIGGER_HIGH_DELAY);
gpio_write(dev->trigger_pin, false);
// Previous ping isn't ended
if (gpio_read(dev->echo_pin))
return ULTRASONIC_ERROR_PING;
// Wait for echo
uint32_t timeout = sdk_system_get_time() + PING_TIMEOUT;
while (!gpio_read(dev->echo_pin))
{
if (sdk_system_get_time() >= timeout)
return ULTRASONIC_ERROR_PING_TIMEOUT;
}
// got echo, measuring
uint32_t echo_start = sdk_system_get_time();
uint32_t time = echo_start;
timeout = echo_start + max_distance * ROUNDTRIP;
while (gpio_read(dev->echo_pin))
{
time = sdk_system_get_time();
if (time >= timeout)
return ULTRASONIC_ERROR_ECHO_TIMEOUT;
}
return (time - echo_start) / ROUNDTRIP;
}

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/*
* Driver for ultrasonic range meters, e.g. HC-SR04, HY-SRF05 and so on
*
* Part of esp-open-rtos
* Copyright (C) 2016 Ruslan V. Uss <unclerus@gmail.com>
* BSD Licensed as described in the file LICENSE
*/
#ifndef EXTRAS_ULTRASONIC_H_
#define EXTRAS_ULTRASONIC_H_
#include <stdint.h>
#ifdef __cplusplus
extern "C" {
#endif
#define ULTRASONIC_ERROR_PING (-1)
#define ULTRASONIC_ERROR_PING_TIMEOUT (-2)
#define ULTRASONIC_ERROR_ECHO_TIMEOUT (-3)
/**
* Device descriptor
*/
typedef struct
{
uint8_t trigger_pin;
uint8_t echo_pin;
} ultrasonic_sensor_t;
/**
* Init ranging module
* \param dev Pointer to the device descriptor
*/
void ultrasoinc_init(const ultrasonic_sensor_t *dev);
/**
* Measure distance
* \param dev Pointer to the device descriptor
* \param max_distance Maximal distance to measure, centimeters
* \return Distance in centimeters or ULTRASONIC_ERROR_xxx if error occured
*/
int32_t ultrasoinc_measure_cm(const ultrasonic_sensor_t *dev, uint32_t max_distance);
#ifdef __cplusplus
}
#endif
#endif /* EXTRAS_ULTRASONIC_H_ */