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66 lines
1.5 KiB
66 lines
1.5 KiB
#pragma once
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//
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// Utilities for working with the HC-SR04 ultrasonic sensor
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// Can be easily modified to work with other similar modules
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//
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// It's required that you call the sonar_handle_* functions from your ISRs
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// See example program for more info.
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//
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#include <stdint.h>
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#include <stdbool.h>
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#include "lib/pins.h"
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// Calib constant for the module
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// CM = uS / _DIV_CONST
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#define _SNR_DIV_CONST 58
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// Max module distance in MM
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#define _SNR_MAX_DIST 4000
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// Trigger time in uS
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#define _SNR_TRIG_TIME 10
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// Sonar data object
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typedef struct {
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PORT_P port; // Tx PORT
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uint8_t ntx; // Tx bit number
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PORT_P pin; // Rx PIN
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uint8_t nrx; // Rx bit number
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uint8_t bank; // Rx PCINT bank
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} sonar_t;
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extern volatile bool sonar_busy;
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extern volatile int16_t sonar_result;
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// Create a Sonar port
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// Args: sonar_t* so, Trig pin, Echo pin
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#define sonar_init(so, trig, echo) do { \
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as_output(io_pack(trig)); \
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as_input_pu(io_pack(echo)); \
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_sonar_init_do(so, &io2port(io_pack(trig)), io2n(io_pack(trig)), &io2pin(io_pack(echo)), io2n(io_pack(echo))); \
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} while(0)
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// private, in header because of the macro.
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void _sonar_init_do(sonar_t* so, PORT_P port, uint8_t ntx, PORT_P pin, uint8_t nrx);
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/**
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* Start sonar measurement
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* Interrupts must be enabled
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* TIMER 1 will be used for the async measurement
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*/
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bool sonar_start(sonar_t* so);
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/** Handle TIMER1_OVF (returns true if consumed) */
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bool sonar_handle_t1ovf();
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/** Handle pin change interrupt (returns true if consumed) */
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bool sonar_handle_pci();
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