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#include <pic.h> //obligatory
//Quartz 4Mhz
#define PIC_CLK 4000000
//The delay routines
#include "delay.h"
//I use a chrystal and my code is not protected
__CONFIG(FOSC0|PWRTE |CP);
/**
* RS232 link management at 9600 bauds
*
*/
//This replaces bitfields implementation
#define PORTBIT(adr, bit) ((unsigned)(&adr)*8+(bit))
#define getbit(data,bitno) ((data>>bitno)&0x01)
#define setnbit(data,bitno) (data<<bitno)
#define setbit(data,bitno,value) (data&(~setnbit(1,bitno))|setnbit(value,bitno))
#define togglebit(data) (data^0x01)
//Duration in microsecond (the microcontroler is blind during this duration
if the signal change on its 'IT interruption pin)
#define TirqLatency 60
/******************** IR HP48 **********************************/
//Receiver parameters
//-----------------------
#define Tbit_rx_HP48IR 416 // 1/2400 bauds
#define Duration_HP48IR_rx_pulsehigh 300 // les 52us ont ‚t‚
rallong‚s par le NE555 … 300us
#define Jump_over_HP48IR_rx_startmotif (Tbit_rx_HP48IR-TirqLatency+(Duration_HP48IR_rx_pulsehigh/2))
#define Nb_HP48IR_rx_databits 8
#define Jump_over_HP48IR_rx_datamotif (Tbit_rx_HP48IR-40)
//Emitter parameters
//----------------------
#define Tbit_tx_HP48IR 416 // 1/2400 bauds
#define Duration_HP48IR_tx_highlevel 52
#define Duration_HP48IR_tx_lowlevel (Tbit_tx_HP48IR-Duration_HP48IR_tx_highlevel-50)
#define Nb_HP48IR_tx_databits 8
#define Nb_HP48IR_tx_stopbits 2
#define Duration_HP48IR_tx_stopmotifs (Nb_HP48IR_tx_stopbits*Tbit_tx_HP48IR)
#define ITMask 0B10110000
//---- Pin attributions -------------
static bit HP48IR_IN @ PORTBIT(PORTB,5);
static bit HP48IR_OUT @ PORTBIT(PORTB,6);
//To display voir the char on a 8 leds panel
volatile bit D1 @ PORTBIT(PORTB, 3);
volatile bit D2 @ PORTBIT(PORTB, 2);
volatile bit D3 @ PORTBIT(PORTB, 1);
volatile bit D4 @ PORTBIT(PORTB, 0);
volatile bit D5 @ PORTBIT(PORTA, 3);
volatile bit D6 @ PORTBIT(PORTA, 2);
volatile bit D7 @ PORTBIT(PORTA, 1);
volatile bit D8 @ PORTBIT(PORTA, 0);
//---- Working variables ---------------------------
//used by the delay routines
volatile unsigned int timeout;
//buffer variable
unsigned char Buff;
unsigned char TxBuff; // char to send
unsigned char RxBuff;// char received
//------ Declaration of the HP48IR routines -------------------------------
void HPget(void); /* Receive an IR frame from HP and decode it*/
void HPsend(void); /*Send a char to HP48 by the IR port(SFH405)*/
//-------Panel Leds routines -------------
void WriteParport(void);
void ReadParport(void);
//------ Main program to init ports and allow interrupts---------
main()
{
//Indicate pin direction (INPUT /OUTPUTS)
TRISB = ITMask;
TRISA = 0;
//Set the default pin levels
PORTA = 0;
PORTB = 0b10000000;
HP48IR_OUT=1;
//grant the interrupts on the port B
RBIE=1;
GIE=1;
//infinite loop to disturb
for(;;) {
}
}
//-----Show the Buff content on the 8 leds panel
void WriteParport(void) {
D1=getbit(Buff,0);
D2=getbit(Buff,1);
D3=getbit(Buff,2);
D4=getbit(Buff,3);
D5=getbit(Buff,4);
D6=getbit(Buff,5);
D7=getbit(Buff,6);
D8=getbit(Buff,7);
}
//----Retreive the value of the 8 leds (D1-D8) and store
it into Buff .
void ReadParport(void) {
Buff=setbit(Buff,0,D1);
Buff=setbit(Buff,1,D2);
Buff=setbit(Buff,2,D3);
Buff=setbit(Buff,3,D4);
Buff=setbit(Buff,4,D5);
Buff=setbit(Buff,5,D6);
Buff=setbit(Buff,6,D7);
Buff=setbit(Buff,7,D8);
}
unsigned char prev_portb=0B10000000; //latch the value of B port
// Interruption routine triggered by a signal change (and lasts more
thanTirqLatency!) on any pin:
// RB7, RB6,RB5,RB4 and RB0
interrupt isr()
{
//Try to know which pin change..
if (RBIF)
{
RBIF=0; //Interruption acquittment
if ((prev_portb ^ (PORTB&ITMask)) == 0B00100000){
//C'est la Broche RB5=HP IN which has changed, a char need to be
analyzed.
if ((PORTB & 0B00100000) == 0) //If it is the falling edge of
the start bit then
{
//receive the char behind
HPget();
Buff=RxBuff;
//display its value on the panel leds
WriteParport();
TxBuff=RxBuff;
//and send it for acknowledgment
HPsend(); //la liaison HP est half duplex - attention à la
casse!
//RSsend();
}
}
prev_portb=PORTB&ITMask; //Next char..
}
}
// HP48 IR routines
//-------------------
//Receive a HP48 char by the use of the HSDL1001 infrared interface.
void HPget(void){
unsigned t;
//Jump over the start pattern and select the half pattern
//(D1 has been used for debug.)
//D1=1;
DelayBigUs(Jump_over_HP48IR_rx_startmotif);
//D1=0;
//Read the 8 data patterns
for(t=Nb_HP48IR_rx_databits;t--;) {
//get the value pattern and stores it at the good position in RxBuff
RxBuff=RxBuff | ((HP48IR_IN&0x01)<<(Nb_HP48IR_rx_databits-1));
if(t > 0)
RxBuff=RxBuff >> 1;
DelayBigUs(Jump_over_HP48IR_rx_datamotif);
//D1=0;
}
//Stop patterns ignored..
}
/* Send a char to HP48 by IR
* Pattern 0=Pulse 52us ,Pattern 1=no pulse, Tir=416.7us
**/
void HPsend(void){
unsigned b;
unsigned IR_Data;
//Start pattern
HP48IR_OUT=1;
//D1=1; for debug
DelayUs(Duration_HP48IR_tx_highlevel); //warning : we use DelayUS because
52 <255
HP48IR_OUT=0;
//D1=0;
DelayBigUs(Duration_HP48IR_tx_lowlevel); //416.7-52=364us Low Pulse
//Generates data patttern signal each Tir=416.7us
for(b=Nb_HP48IR_tx_databits;b--;) {
IR_Data=TxBuff&0x01;
if(IR_Data==0)
HP48IR_OUT=1;
//D1=1;
DelayUs(Duration_HP48IR_tx_highlevel);
if(IR_Data==0)
HP48IR_OUT=0;
//D1=0;
if(b>0)
TxBuff=TxBuff>>1;
DelayBigUs(Duration_HP48IR_tx_lowlevel); //416.7-52=364us Pulse bas
; 364 >255 so use DelayBigUs
}
//stop pattern
HP48IR_OUT=0; //optional
DelayBigUs(Duration_HP48IR_tx_stopmotifs); //2*416.7
}
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