You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
67 lines
1.4 KiB
67 lines
1.4 KiB
10 years ago
|
#pragma once
|
||
|
|
|
||
|
|
//
|
||
|
|
// Utilities for working with the HC-SR04 ultrasonic sensor
|
||
|
|
// Can be easily modified to work with other similar modules
|
||
|
|
//
|
||
|
|
// It's required that you call the sonar_handle_* functions from your ISRs
|
||
|
|
// See example program for more info.
|
||
|
|
//
|
||
|
|
|
||
|
|
#include <stdint.h>
|
||
|
|
#include <stdbool.h>
|
||
|
|
|
||
|
|
#include "iopins.h"
|
||
|
|
|
||
|
|
// Calib constant for the module
|
||
|
|
// CM = uS / _DIV_CONST
|
||
|
|
#define _SNR_DIV_CONST 58
|
||
|
|
|
||
|
|
// Max module distance in MM
|
||
|
|
#define _SNR_MAX_DIST 4000
|
||
|
|
|
||
|
|
// Trigger time in uS
|
||
|
|
#define _SNR_TRIG_TIME 10
|
||
|
|
|
||
|
|
|
||
|
|
// Sonar data object
|
||
|
|
typedef struct {
|
||
|
|
PORT_P port; // Tx PORT
|
||
|
|
uint8_t ntx; // Tx bit number
|
||
|
|
PORT_P pin; // Rx PIN
|
||
|
|
uint8_t nrx; // Rx bit number
|
||
|
|
uint8_t bank; // Rx PCINT bank
|
||
|
|
} sonar_t;
|
||
|
|
|
||
|
|
|
||
|
|
extern volatile bool sonar_busy;
|
||
|
|
extern volatile int16_t sonar_result;
|
||
|
|
|
||
|
|
|
||
|
|
// Create a Sonar port
|
||
|
|
// Args: sonar_t* so, Trig pin, Echo pin
|
||
|
|
#define sonar_init(so, trig, echo) do { \
|
||
|
|
as_output(trig); \
|
||
|
|
as_input_pu(echo); \
|
||
|
|
_sonar_init_do(so, &_port(trig), _pn(trig), &_pin(echo), _pn(echo)); \
|
||
|
|
} while(0)
|
||
|
|
|
||
|
|
// private, in header because of the macro.
|
||
|
|
void _sonar_init_do(sonar_t* so, PORT_P port, uint8_t ntx, PORT_P pin, uint8_t nrx);
|
||
|
|
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Start sonar measurement
|
||
|
|
* Interrupts must be enabled
|
||
|
|
* TIMER 1 will be used for the async measurement
|
||
|
|
*/
|
||
|
|
bool sonar_start(sonar_t* so);
|
||
|
|
|
||
|
|
|
||
|
|
/** Handle TIMER1_OVF (returns true if consumed) */
|
||
|
|
bool sonar_handle_t1ovf();
|
||
|
|
|
||
|
|
|
||
|
|
/** Handle pin change interrupt (returns true if consumed) */
|
||
|
|
bool sonar_handle_pci();
|