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PWM on a PIC

If it helps, here is the C18 code to read a Sony remote. If you can program it on a stand alone chip you might be able to work out whats wrong.

Mike.
Code: 
#define IR_in   PORTAbits.RA6       //define as needed
#define IR_tris TRISAbits.TRISA6

unsigned char GetPulse(void){
unsigned char count;
    count=0;
    IR_tris=1;
    while(IR_in==1);            //wait for high
    while(IR_in==0){            //time low period
        count++;
        Delay100TCYx(1);        //50uS assumes 8MHz
    }
    return count;
}

void GetIR(char *cmd,char *dev){
char i;
    *cmd=0;
    *dev=0;
    while(GetPulse()<40);       //wait for start pulse
    for(i=0;i<7;i++){
        *cmd=*cmd>>1;
        if(GetPulse()>18)
            *cmd|=0x40;
    }
    for(i=0;i<5;i++){
        *dev=*dev>>1;
        if(GetPulse()>18)
            *dev|=0x10;
    }
}

//you would call it by doing,

char command,device;
    GetIR(&command,&device);      //note pointers passed

//command and device are now valid.
P.S. have you looked at an actual remote through the camera for comparison.
 
blueroomelectronics said:
Never thought about that, how much lower?
Click to expand...

You normally pulse IR diodes in remote controls at between 1 and 2 amps! - notice that there's a LOT of time spent outputting nothing in the datastream, this allows the diode not to overheat or fail.

Generally the mark/space ratio of the 38KHz itself is 50/50 - I've played with different ratios, and it seems to make very little difference.
 
I think what Pommie was trying to say is a narrow pulse would keep the LED average current lower while allowing a higher peak current. All is well and good but the LED may not like single stepping via a debugger. I also though IR LEDs were closer to 100ma max pulsed.
 
AtomSoft,

Code: 
// 37.7kHZ PWM IR carrier signal
#include <p18f1320.h>
#include <delays.h>
#pragma config WDT = OFF,OSC = INTIO2,LVP = OFF

void Delay10TCYx(PARAM_SCLASS unsigned char);
void Delay100TCYx(PARAM_SCLASS unsigned char);
void Delay1KTCYx(PARAM_SCLASS unsigned char);
void Delay10KTCYx(PARAM_SCLASS unsigned char);
void MyL0(void);
void MyL1(void);

void main(void) {    

  [B]  OSCCON=0x72;[/B] // speed up the clock to 8MHz


Code: 
bit 6-4 IRCF2:IRCF0: Internal Oscillator Frequency Select bits

111 = 8 MHz (8 MHz source drives clock directly)
110 = 4 MHz
101 = 2 MHz
100 = 1 MHz
011 = 500 kHz
010 = 250 kHz
001 = 125 kHz
000 = 31 kHz (INTRC source drives clock directly)


If the people gave you PWM setups for a 8MHz clock you need to change your ckock freq from 4 to 8MHz. I would check but I am running behind.
 
It blinks because one cannot see the individual On/OFF of the 38KHz carrier wave cycle but eye can detect the period between "carrier present" and "no carrier".

Changing the mark/space ratio of 38KHz allows one to use still higher pulse current to the IR emitter.
 
3v0 said:
If the people gave you PWM setups for a 8MHz clock you need to change your ckock freq from 4 to 8MHz. I would check but I am running behind.
Click to expand...
OSCCON=0x72 does give 8MHz. Even if you have the config set to HS and a 20MHz crystal attached.

Mike.
 
Pommie said:
OSCCON=0x72 does give 8MHz. Even if you have the config set to HS and a 20MHz crystal attached.

Mike.
Click to expand...

My bad. very :o

:) May be a good day to stay in bed :)

EDIT:

I would go to radio shack and get an IR detector and see if it can detect the modulated IR. If that works it has to be the data.
 
Last edited:
ok this sucks! lol i can always make my own protocol right?

I wanted to use sony's because i have code to read sonys already but i guess ill have to remake everything which shouldnt be that hard if i make my own code just change some variables around and stuff..

So is it possible to make a custom protocol?

Like

Start Bit = 4ms
Space = 1ms
Logic High = 3ms
Logic Low = 2ms


Something like that.... but about 16bit instead of sony 12bit
 
Last edited:
AtomSoft said:
ok this sucks! lol i can always make my own protocol right?
Click to expand...

Yes, but what's wrong with using Sony's?.

I wanted to use sony's because i have code to read sonys already but i guess ill have to remake everything which shouldnt be that hard if i make my own code just change some variables around and stuff..

So is it possible to make a custom protocol?

Like

Start Bit = 4ms
Space = 1ms
Logic High = 3ms
Logic Low = 2ms


Something like that.... but about 16bit instead of sony 12bit
Click to expand...

Check my tutorials, Sony have three different word lengths, with 12 being the shortest.

Nothing wrong with using the Sony SIRC's system, it's simple and easy, just allocate your own device ID for an interference free system.
 
I'm missing something, why would you have to make your own protocol? 8MHz is uber fast for an IR transmission. Especially if it's done with the PWM.

Here's a suggestion, here's the unmodified TX source from
http://www.sixca.com/eng/articles/remote/index.html
It shouldn't be difficult to make it work on the Junebugs 18F1320 (the code will get smaller) It's only 4MHz and doesn't even use the PWM module. I've got to run but I'll take a look this afternoon to get it running on the Junebug.

Code: 
;------------------------------------------------------
; PROJECT : 3 CHANNEL TX IR REMOTE
; CRYSTAL 4 MHz
; MPLAB : 7.11 , Assembly
; RC5 FORMAT @38KHz , 35% DUTY CYCLE
; ADDRESS = 0X0B  0000 1011 you may change
; CH1  = 0X01
; CH2  = 0X02
; CH3  = 0X03
; NOT USE TOGGLE ALWAY = 0
; WWW.SIXCA.COM
; 4-JULY 2005
; 
; FREE TO USE FOR PERSONAL OR EVEN COMERCIAL PRODUCT
;------------------------------------------------------

    list P=12F629
    #include <P12F629.INC>
    __config _WDT_OFF & _XT_OSC & _CP_ON & _CPD_ON & _BODEN_OFF & _MCLRE_OFF & _PWRTE_ON


#DEFINE CH1    GPIO,0    ; CONNECT WITH TX SWITCH CHANNEL 1
#DEFINE CH2    GPIO,1    ; CONNECT WITH TX SWITCH CHANNEL 2
#DEFINE CH3    GPIO,3    ; CONNECT WITH TX SWITCH CHANNEL 3
#DEFINE IR    GPIO,2    ; CONNECT WITH IR LED WITH TRANSISTOR DRIVES
#DEFINE TOG_BIT TOGGLE,0 ; TOGLE BIT NOT USE FOR THIS PROJECT    
#DEFINE CH1_CMD    0X01    ; CHANNEL 1 COMMAND
#DEFINE CH2_CMD    0X02    ; CHANNEL 2 COMMAND
#DEFINE CH3_CMD    0X03    ; CHANNEL 3 COMMAND


CNT1    EQU    20H
CNT2    EQU    21H
CNT3    EQU    22H
CNT4    EQU    23H
TOGGLE    EQU    24H
CMD    EQU    25H    ; IR COMMAND BUFFER

    ORG    000
    
    BCF    IR
    ;BSF    STATUS,RP0
    ;CALL    0X3FF
    ;MOVWF    OSCCAL
    ;BCF    STATUS,RP0
    CALL    DEBOUNCE
    ;
    MOVLW    0X07
    MOVWF    CMCON    ; MAKE ALL GPIO TO DIGITAL I/O
    BSF    STATUS,RP0
    BCF    OPTION_REG,7    ; ENABLE WEAK PULL-UP
    BCF    WPU,2        ; DISABLE WEAK PULL-UP FOR GPIO2
    MOVLW    B'00001011'    ; GPIO<0,1,3> = INPUT , GPIO 2 = OUTPUT
    MOVWF    TRISIO
    BSF    IOCB,IOCB0
    BSF    IOCB,IOCB1
    BSF    IOCB,IOCB3
    BSF    INTCON,GPIE
    BCF    STATUS,RP0    
    BCF    INTCON,GIE    
    BCF    TOG_BIT
    
;------------------------------------
; MAIN LOOP    
MAIN:    SLEEP    ; GOTO SLEEP MODE(I a sleepy! and need to save my energy)
    BTFSS    CH1
    GOTO    DO_CH1
    BTFSS    CH2
    GOTO    DO_CH2
    BTFSS    CH3
    GOTO    DO_CH3
    GOTO    MAIN    

;------------------------------------
DO_CH1:    CALL    DEBOUNCE
    BTFSC    CH1
    GOTO    MAIN
    MOVLW    CH1_CMD    ; LOAD COMMANE FOR CHANNEL 1
    MOVWF    CMD
    CALL    SEND_RC5
    ;
    BTFSS    CH1
    GOTO    $-1    ; WAIT FOR SWITCH RELEASED
    ;
    CALL    DEBOUNCE    ; DELAY AFTER SWITCH RELEASED
    GOTO    MAIN

;------------------------------------    
DO_CH2:    CALL    DEBOUNCE
    BTFSC    CH2
    GOTO    MAIN
    MOVLW    CH2_CMD    ; LOAD COMMANE FOR CHANNEL 1
    MOVWF    CMD
    CALL    SEND_RC5
    ;
    BTFSS    CH2
    GOTO    $-1    ; WAIT FOR SWITCH RELEASED
    ;
    CALL    DEBOUNCE    ; DELAY AFTER SWITCH RELEASED
    GOTO    MAIN
    ;
;------------------------------------    
DO_CH3:    CALL    DEBOUNCE
    BTFSC    CH3
    GOTO    MAIN
    MOVLW    CH3_CMD    ; LOAD COMMANE FOR CHANNEL 1
    MOVWF    CMD
    CALL    SEND_RC5
    ;
    BTFSS    CH3
    GOTO    $-1    ; WAIT FOR SWITCH RELEASED
    ;
    CALL    DEBOUNCE    ; DELAY AFTER SWITCH RELEASED
    GOTO    MAIN
    ;    
;======================================
; SEND LOGIC 0
;======================================
LOGIC0:    MOVLW    .32        ; 1
    MOVWF    CNT1        ; 1
    ;
LOG0_1:    BSF    IR        ; 1 MAKE IR HIGH 35% Duty cycle = 9 uS
    GOTO    $+1
    GOTO    $+1
    GOTO    $+1
    GOTO    $+1
    ;
    ;===================================
    BCF    IR        ; 1 MAKE IR LOW 17 uS
    GOTO    $+1
    GOTO    $+1
    GOTO    $+1
    GOTO    $+1
    GOTO    $+1
    GOTO    $+1
    NOP            ; 1
    ;
    DECFSZ    CNT1,F        ; 1/2
    GOTO    LOG0_1        ; 2    26 uS
    ;
    CALL    DELAY_OFF
    RETURN            ; 2
    ;
;======================================
; SEND LOGIC 1
;======================================
LOGIC1:    CALL    DELAY_OFF    ; DELAY 899 uS
    MOVLW    .32        ; 1
    MOVWF    CNT1        ; 1
    ;
LOG1_1:    BSF    IR        ; 1 MAKE IR HIGH 35% Duty cycle = 9 uS
    GOTO    $+1
    GOTO    $+1
    GOTO    $+1
    GOTO    $+1
    ;
    ;===================================
    BCF    IR        ; 1 MAKE IR LOW 17 uS
    GOTO    $+1
    GOTO    $+1
    GOTO    $+1
    GOTO    $+1
    GOTO    $+1
    GOTO    $+1
    NOP            ; 1
    ;
    DECFSZ    CNT1,F        ; 1/2
    GOTO    LOG1_1        ; 2
    ;
    RETURN            ; 2
    ;
;======================================
; DELAY FOR NO CARRAIR
; DELAY ABOUT 835 uS
;======================================
DELAY_OFF:
    MOVLW    5        ; 1
    MOVWF    CNT3        ; 1    
    MOVLW    .54        ; 1
    MOVWF    CNT4        ; 1
    DECFSZ    CNT4,F        ; 1/2
    GOTO    $-1        ; 2    
    DECFSZ    CNT3,F      ; 1/2
    GOTO    $-5        ; 2
    RETURN            ; 2
    
;======================================
; SEND RC5 TO REMOTE
; INPUT : CMD (6 BIT IR COMMAND)
;======================================
SEND_RC5:
    ; SEND 2 START  BIT
    CALL    LOGIC1
    CALL    LOGIC1
    ; SEND TOGGLE BIT
    BTFSS    TOG_BIT
    GOTO    $+3
    CALL    LOGIC1
    GOTO    $+2
    CALL    LOGIC0

    ; SEND ADDRESS 5 BIT FIX AT 01011 (0X0B) IT MAY BE CHANGED BY YOU
    CALL    LOGIC0    ; 0  MSB FIRST BIT 4
    CALL    LOGIC1    ; 1
    CALL    LOGIC0    ; 0
    CALL    LOGIC1    ; 1
    CALL    LOGIC1    ; 1  LSB BIT 0
    ;
    ; SEND COMMAND 6 BIT(00HH LLLL) MSB FIRST
    BCF    STATUS,C
    RLF    CMD,F    ; AFTER FIRST ROTAGE 0HHL LLL0
    RLF    CMD,F    ; AFTER SECOND ROTAGE HHLL LL00
    ;
    MOVLW    6
    MOVWF    CNT2
    ;
    RLF    CMD,F        ; SEND MSB FIRST
    BTFSS    STATUS,C
    GOTO    $+3
    CALL    LOGIC1
    GOTO    $+2
    ;
    CALL    LOGIC0
    DECFSZ    CNT2,F
    GOTO    $-7
    ;
    RETLW    0        
    ;    
    
;======================================
; DEBOUNCE SWITCH
; DELAY 15 mS
;======================================
DEBOUNCE:
    MOVLW    .1        ; 1
    MOVWF    CNT1        ; 1
DEL_1:    MOVLW    .20
    MOVWF    CNT2        ; 1
DEL_2:    CLRF    CNT3        ; 1
DEL_3:    DECFSZ    CNT3,F        ; 1/2
    GOTO    DEL_3        ; 2
    DECFSZ    CNT2,F        ; 1/2
    GOTO    DEL_2        ; 2
    DECFSZ    CNT1,F        ; 1/2
    GOTO    DEL_1        ; 2
    RETLW    0        ; 2
    
    END
 
This finally got to me and I dug out my scope and had a play.

Can you try,
Code: 
#include <p18f1320.h> 
#include "delays.h"

#pragma config WDT = OFF, LVP = OFF, OSC = INTIO2

void sendbyte(char Num,char bits){
char i;
    for(i=0;i<bits;i++){
        CCPR1L = 0x1A;                  // 0
        CCP1CON = 0x1C;                 // 50%
        if(Num&1==1)
            Delay100TCYx(24);           //1.2mS
        else
            Delay100TCYx(12);           //0.6mS
        Num=Num>>1;
        CCPR1L = 0x00; //Space
        CCP1CON = 0x0C ; // 0%
        Delay100TCYx(12);               //0.6mS
    }
}

void main(void) {    
    OSCCON=0x72; // speed up the clock to 8MHz
    ADCON1 = 0; 
    TRISBbits.TRISB3 = 0;
    PR2 = 0b00110100 ;
    T2CON = 0b00000100 ;
    CCPR1L = 0b00011010 ;
    CCP1CON = 0b00011100 ;
    while(1) {
        CCPR1L = 0x1A; // 0
        CCP1CON = 0x1C ; // 50%
        Delay100TCYx(48);               //2.4mS pulse
        CCPR1L = 0x00; //Space
        CCP1CON = 0x0C ; // 0%
        Delay100TCYx(12);               //0.6mS
        sendbyte(18,7);                 //device 18
        sendbyte(1,6);                  //command 1
        Delay1KTCYx(100);
     }    
}

The problem with your original code was you just aren't sending enough bits.

Mike.
 
Last edited:
no go pommie i even tried sending command then device but nothing...

.. also how come i cant open LA anymore. For some reason its greyed out now

EDIT: Also tried to send 5 bits for not 6
 
Last edited:
Well I've just got the code converted yet it's untested. I'm just posting it because I've got work that has to be done before I can play.
Code: 
;------------------------------------------------------
; PROJECT : 3 CHANNEL TX IR REMOTE
; CRYSTAL 4 MHz
; MPLAB : 7.11 , Assembly
; RC5 FORMAT @38KHz , 35% DUTY CYCLE
; ADDRESS = 0X0B  0000 1011 you may change
; CH1  = 0X01
; CH2  = 0X02
; CH3  = 0X03
; NOT USE TOGGLE ALWAY = 0
; WWW.SIXCA.COM
; 4-JULY 2005
; 
; FREE TO USE FOR PERSONAL OR EVEN COMERCIAL PRODUCT
; Modified by William Richardson for use with the
; blueroomelectronics Junebug Tutor
; BETA (not tested...)
;------------------------------------------------------

    list P=18F1320
    #include <P18F1320.INC>
    CONFIG    OSC=INTIO2,WDT=OFF,LVP=OFF

#DEFINE CH1    PORTB,0    ; CONNECT WITH TX SWITCH CHANNEL 1
#DEFINE CH2    PORTB,2    ; CONNECT WITH TX SWITCH CHANNEL 2
#DEFINE CH3    PORTB,5    ; CONNECT WITH TX SWITCH CHANNEL 3
#DEFINE IR    LATB,3    ; CONNECT WITH IR LED WITH TRANSISTOR DRIVES
#DEFINE TOG_BIT    TOGGLE,0
#DEFINE CH1_CMD    0X01    ; CHANNEL 1 COMMAND
#DEFINE CH2_CMD    0X02    ; CHANNEL 2 COMMAND
#DEFINE CH3_CMD    0X03    ; CHANNEL 3 COMMAND

    cblock     0x00
    CNT1,CNT2,CNT3,CNT4,TOGGLE,CMD
    endc
    
    ORG    0x00
    movlw    0x62        
    movwf    OSCCON        ; 4MHz clock (1us instruction)
    setf    ADCON1        ; set all I/O to digital
    bcf    INTCON2,RBPU    ; enable PORTB input pullups
    clrf    PORTB        ; zero the output bits        
    MOVLW    B'11110111'    ; IR Output on RB3
    MOVWF    TRISB
    rcall    DEBOUNCE
    BCF    TOG_BIT
    
;------------------------------------
; MAIN LOOP    
MAIN:    
;    SLEEP    ; removed for test GOTO SLEEP MODE(I a sleepy! and need to save my energy)
    BTFSS    CH1
    bra    DO_CH1
    BTFSS    CH2
    bra    DO_CH2
    BTFSS    CH3
    bra    DO_CH3
    bra    MAIN    

;------------------------------------
DO_CH1:    rcall    DEBOUNCE
    BTFSC    CH1
    bra    MAIN
    MOVLW    CH1_CMD        ; LOAD COMMANE FOR CHANNEL 1
    MOVWF    CMD
    rcall    SEND_RC5
    BTFSS    CH1
    bra    $-2        ; WAIT FOR SWITCH RELEASED
    rcall    DEBOUNCE    ; DELAY AFTER SWITCH RELEASED
    bra    MAIN

;------------------------------------    
DO_CH2:    rcall    DEBOUNCE
    BTFSC    CH2
    bra    MAIN
    MOVLW    CH2_CMD        ; LOAD COMMANE FOR CHANNEL 1
    MOVWF    CMD
    rcall    SEND_RC5
    BTFSS    CH2
    bra    $-2        ; WAIT For SWITCH RELEASED
    rcall    DEBOUNCE    ; DELAY AFTER SWITCH RELEASED
    bra    MAIN
    ;
;------------------------------------    
DO_CH3:    rcall    DEBOUNCE
    BTFSC    CH3
    bra    MAIN
    MOVLW    CH3_CMD        ; LOAD COMMAND FOR CHANNEL 1
    MOVWF    CMD
    rcall    SEND_RC5
    BTFSS    CH3
    bra    $-2        ; WAIT FOR SWITCH RELEASED
    rcall    DEBOUNCE    ; DELAY AFTER SWITCH RELEASED
    bra    MAIN
    ;    
;======================================
; SEND LOGIC 0
;======================================
LOGIC0:    MOVLW    .32        ; 1
    MOVWF    CNT1        ; 1
LOG0_1:    BSF    IR        ; 1 MAKE IR HIGH 35% Duty cycle = 9 uS
    bra    $+2
    bra    $+2
    bra    $+2
    bra    $+2
    BCF    IR        ; 1 MAKE IR LOW 17 uS
    bra    $+2
    bra    $+2
    bra    $+2
    bra    $+2
    bra    $+2
    bra    $+2
    nop            ; 1
    DECFSZ    CNT1,F        ; 1/2
    bra    LOG0_1        ; 2    26 uS
    rcall    DELAY_OFF
    RETURN            ; 2
    ;
;======================================
; SEND LOGIC 1
;======================================
LOGIC1:    rcall    DELAY_OFF    ; DELAY 899 uS
    MOVLW    .32        ; 1
    MOVWF    CNT1        ; 1
LOG1_1:    BSF    IR        ; 1 MAKE IR HIGH 35% Duty cycle = 9 uS
    bra    $+2
    bra    $+2
    bra    $+2
    bra    $+2
    BCF    IR        ; 1 MAKE IR LOW 17 uS
    bra    $+2
    bra    $+2
    bra    $+2
    bra    $+2
    bra    $+2
    bra    $+2
    nop            ; 1
    DECFSZ    CNT1,F        ; 1/2
    bra    LOG1_1        ; 2
    RETURN            ; 2
    ;
;======================================
; DELAY FOR NO CARRAIR
; DELAY ABOUT 835 uS
;======================================
DELAY_OFF:
    MOVLW    .5        ; 1
    MOVWF    CNT3        ; 1    
Loop1:    MOVLW    .54        ; 1
    MOVWF    CNT4        ; 1
    decfsz    CNT4,F        ; 1/2
    bra    $-2        ; 2    
    decfsz    CNT3,F      ; 1/2
    bra    Loop1:        ; 2
    return            ; 2
    
;======================================
; SEND RC5 TO REMOTE
; INPUT : CMD (6 BIT IR COMMAND)
;======================================
SEND_RC5:
    rcall    LOGIC1    ; SEND 2 START  BIT
    rcall    LOGIC1
    BTFSS    TOG_BIT    ; SEND TOGGLE BIT
    bra    $+6
    rcall    LOGIC1
    bra    $+4
    rcall    LOGIC0

; SEND ADDRESS 5 BIT FIX AT 01011 (0X0B) IT MAY BE CHANGED BY YOU
    rcall    LOGIC0    ; 0  MSB FIRST BIT 4
    rcall    LOGIC1    ; 1
    rcall    LOGIC0    ; 0
    rcall    LOGIC1    ; 1
    rcall    LOGIC1    ; 1  LSB BIT 0
    
; SEND COMMAND 6 BIT(00HH LLLL) MSB FIRST
    bcf    STATUS,C
    rlcf    CMD,F    ; AFTER FIRST ROTAGE 0HHL LLL0
    rlcf    CMD,F    ; AFTER SECOND ROTAGE HHLL LL00
    MOVLW    .6
    MOVWF    CNT2
    rlcf    CMD,F        ; SEND MSB FIRST
    btfss    STATUS,C
    bra    $+6
    rcall    LOGIC1
    bra    $+4
    rcall    LOGIC0
    decfsz    CNT2,F
    bra    $-14        ; seems wrong..
    retlw    0        
    
;======================================
; DEBOUNCE SWITCH
; DELAY 15 mS
;======================================
DEBOUNCE:
    MOVLW    .1        ; 1
    MOVWF    CNT1        ; 1
DEL_1:    MOVLW    .20
    MOVWF    CNT2        ; 1
DEL_2:    CLRF    CNT3        ; 1
DEL_3:    DECFSZ    CNT3,F        ; 1/2
    bra    DEL_3        ; 2
    DECFSZ    CNT2,F        ; 1/2
    bra    DEL_2        ; 2
    DECFSZ    CNT1,F        ; 1/2
    bra    DEL_1        ; 2
    RETLW    0        ; 2
    END
 
The code I posted above (changed to 5 bits - doh), gives a very clear signal on the scope (and so did your original code) and so I would guess it is your actual transmitter part that is at fault.

Mike.
 
He're an App note on IR Remote control transmitter from Microchip
AN1064
40KHz is the carrier frequency so here are the values for a 4MHz OSC.
Code: 
/*
 * PWM registers configuration
 * Fosc = 4000000 Hz
 * Fpwm = 40000.00 Hz (Requested : 40000 Hz)
 * Duty Cycle = 35 %
 * Resolution is 6 bits
 * Prescaler is 1
 * Ensure that your PWM pin is configured as digital output
 * see more details on http://www.micro-examples.com/
 * this source code is provided 'as is',
 * use it at your own risks
 */
PR2 = 0b00011000 ;
T2CON = 0b00000100 ;
CCPR1L = 0b00001000 ;
CCP1CON = 0b00101100 ;
 

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