porklib: Simple library for programming Arduino in C
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avr-lib/examples/dht11/lib/sonar.h

66 lines
1.4 KiB

#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();