/*
* srf.h
* defines the functions and constants required for the sonic range finder
*/

#ifndef SRF_H
#define SRF_H

#define  B4TIME_CONFIG 0x4a  
					/*  01001010 value to load into timer B0 mode register
                        ||||||||_  TMOD0,TMOD1: PULSE MEASUREMENT MODE
                        ||||||____ MR0,MR1:     PULSE WIDTH MODE   
			  		    ||||_______MR2:         = 0 FOR PULSE MEASUREMENT
                        |||_______ MR3:         OVERFLOW FLAG (INPUT)     
                        ||________ TCK0,TCK1:   F DIVIDED BY 8 SELECTED */

#define  B1TIME_CONFIG 0x40  
					/*  01000000 value to load into timer B0 mode register
                        ||||||||_  TMOD0,TMOD1: TIMER MODE (00)
                        ||||||____ MR0,MR1:     NA  =0 
			  		    ||||_______MR2:         =0
                        |||_______ MR3:         =0     
                        ||________ TCK0,TCK1:   F DIVIDED BY 8 SELECTED (01)*/

#define TB1_10US 0x0025
// 24000000/8*0.00001 = 30 = 0x1E -> make it 0x25 to give some slack

#define TB1_10MS 0x7600
// 24000000/8*0.01 = 30000 = 0x7530 -> make it 7600

#define TRIGGER_OUTPUT p9_7
#define TRIGGER_OUTPUT_PD pd9_7

#define ECHO_INPUT	p9_4
#define ECHO_INPUT_PD pd9_4

#define  TB4_IPL 0x03   	// TB4  interrupt priority level
#define  TB1_IPL 0x03		// TB1 interrupt priority level

// SRF state machine states, referenced by global int SRF_state
#define SRF_INIT	1
#define SRF_READY	2
#define SRF_TRIGGER	3
#define SRF_TX		4
#define SRF_MEASURE	5



// prototypes
void srf_init(void);
void tb4_irq(void);
void tb1_irq(void);
int get_srf_reading_mm(void);
void srf_trigger(void);
int is_srf_ready(void);
int is_srf_reading_ready(void);
int get_srf_state(void);

//#define DEBUG_SRF


#endif