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AdamkT1
Joined: 21 Apr 2007
Posts: 44
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| I2c between 18F452(Master) and 16F877 (Slave) |
 Posted: Sun Aug 05, 2007 6:38 am |
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I have used the code suggested by PCM Programmer in old posts, which is given below:
| Code: | #include "18F452.h"
#fuses XT, NOWDT, PROTECT, BROWNOUT, PUT, NOLVP
#use delay(clock=4000000)
#use i2c(Master, sda=PIN_D0, scl=PIN_D1)
#use fast_io(A)
#use fast_io(B)
#use fast_io(C)
//!#use fast_io(D)
#use fast_io(E)
//====================================
void main()
{
int8 data;
SET_TRIS_A(0);
SET_TRIS_B(0);
SET_TRIS_C(0);
SET_TRIS_E(0);
PORTA=0;
PORTB=0;
PORTC=0xFF;
PORTD=0;
PORTE=0;
delay_ms(500);
// Write the letter 'B' to the slave board.
i2c_start();
i2c_write(0xA0);
i2c_write(0x00);
i2c_write('B');
i2c_stop();
// Read from the slave board and display the data.
i2c_start();
i2c_write(0xA0);
i2c_write(0x00);
i2c_start();
i2c_write(0xA1);
data = i2c_read(0);
i2c_stop();
PORTC='B';
PORTB=data;
while(TRUE);
} |
The slave code is EX_SLAVE.C with the modification for Pins for SDA and SCL as per the master code.
The Pin connections are:
1. Have SDA on the Slave connected to SDA on the master.
2. Have SCL on the Slave connected to SCL on the master.
3. SDA and SCL pulled up.
The problem is that the data shown on PORTC & B are different.
Need help... |
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ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
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| Posted: Sun Aug 05, 2007 7:01 am |
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| Quote: | | The slave code is EX_SLAVE.C with the modification for Pins for SDA and SCL as per the master code. |
Sorry, but I can't follow you here. Your slave is a PIC16F877, right? Than why do you change the pin settings for the slave? ex_slave.c was designed for a PIC16F877, changing the pins means you can't use the hardware I2C unit anymore and the interrupt won't work. I'm confused... |
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AdamkT1
Joined: 21 Apr 2007
Posts: 44
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| Posted: Sun Aug 05, 2007 7:31 am |
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Can I put it like this That:
For I2c to work on 16F877(Slave), the only pins that can be used for communications are PIN_C4(SDA) & PIN_C3(SCL) and these pins cannot be changed.
Thank you. |
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ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
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| Posted: Sun Aug 05, 2007 5:07 pm |
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| AdamkT1 wrote: | Can I put it like this That:
For I2c to work on 16F877(Slave), the only pins that can be used for communications are PIN_C4(SDA) & PIN_C3(SCL) and these pins cannot be changed. |
-- Assuming this is a question. -- In short, yes. Save yourself a lot of troubles and use the mentioned hardware pins for an I2C slave.
An I2C master is relative easy to implement and if you don't want to use the designated hardware than the CCS compiler will generate the code for you.
An I2C slave is a whole different story and a lot more difficult. I don't know if the CCS compiler will generate the code for you, at least it can not use interrupts so the given example code is not going to work. The efficient I2C hardware is there in your chip, why not use it? |
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AdamkT1
Joined: 21 Apr 2007
Posts: 44
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| Posted: Sun Aug 05, 2007 8:28 pm |
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| Thank you |
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AdamkT1
Joined: 21 Apr 2007
Posts: 44
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| Posted: Mon Aug 06, 2007 6:44 am |
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This is an SOS call.
I could'nt make the code to work despite countless tries with the code and the readings of posts in this forum for I2C comm.
As per Ckielstra's suggestion, I have changed the slave code to ex_Slave.c but still no good.
For the master, I have done some minor changes in the code, which are:
1) Put the IO directions statements except for PORTC & Put known values on all PORTS.
2) I’ve put the statements inside a while loop.
3) Display the data being sent & received on PORTD & B respectively.
I am pasting both of the codes for help and to ensure that I have not done any mistakes.
In the slave code the changes are:
1) Put the IO directions statements except for PORTC & Put known values on all PORTS.
Master code:
| Code: | #include "18F452.h"
#fuses XT, NOWDT, PROTECT, BROWNOUT, PUT, NOLVP
#use delay(clock=4000000)
#use i2c(Master, sda=PIN_C4, scl=PIN_C3,SLOW)
#use fast_io(A)
#use fast_io(B)
#use fast_io(D)
#use fast_io(E)
//====================================
void main()
{
int8 data;
SET_TRIS_A(0);
SET_TRIS_B(0);
SET_TRIS_D(0);
SET_TRIS_E(0);
PORTA=0;
PORTB=0;
PORTC=0;
PORTD=0;
PORTE=0;
delay_ms(500);
while(TRUE)
{
// Write the letter 'B' to the slave board.
i2c_start();
i2c_write(0xA0); //device address
i2c_write(0); //address of the eeprom byte
i2c_write('B'); //the letter to write
i2c_stop();
DELAY_MS(500);
// Read from the slave board and display the data.
i2c_start();
i2c_write(0xA0);
i2c_write(0x00);
i2c_start();
i2c_write(0xA1);
data = i2c_read(0);
i2c_stop();
DELAY_MS(500);
PORTD='B';
PORTB=data;
delay_ms(100);
PORTA=~PORTA;
}
} |
Slave code:
| Code: | #include "16F877.h"
#use delay(clock=4000000)
#fuses XT,NOWDT
#use i2c(SLAVE,address=0XA0,sda=PIN_C4,scl=PIN_C3,slow)
#use fast_io(A)
#use fast_io(B)
#use fast_io(D)
#use fast_io(E)
BYTE address, buffer[0x10];
#INT_SSP
void ssp_interupt ()
{
BYTE incoming, state;
state = i2c_isr_state();
if(state < 0x80) //Master is sending data
{
incoming = i2c_read();
if(state == 1) //First received byte is address
address = incoming;
if(state == 2) //Second received byte is data
buffer[address] = incoming;
}
if(state == 0x80) //Master is requesting data
{
i2c_write(buffer[address]);
}
}
void main()
{
SET_TRIS_A(0);
SET_TRIS_B(0);
SET_TRIS_D(0);
SET_TRIS_E(0);
PORTA=0;
PORTB=0xFF;
PORTC=0;
PORTD=0;
PORTE=0;
delay_ms(200);
enable_interrupts(GLOBAL);
enable_interrupts(INT_SSP);
WHILE(TRUE)
{
PORTB=Buffer[0];
} //end while
} |
Connection:
I have connected master's SDA & SCL with slave's SDA & SCL respectively and also have pulled them up by 4.7K resistors. |
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ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
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| Posted: Mon Aug 06, 2007 7:30 am |
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- Your code is not complete; where are the definitions for PORTA, PORTB, etc. ?
- What is your compiler version?
- Add NOLVP to your slave code or the PIC will stall with a voltage spike on the LVP input pin.
Try only to implement optimizations when you do have a working program, for example get rid of the FASTIO commands, these might conflict with compiler settings for the I2C ports.
Side note: from a quick glance it looks like your program should be ok, but when things are not working try to stay as close as possible to the original code. You made many more changes than mentioned. Maybe your changes make the code smaller but I don't have the time to compare every line to the original. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Mon Aug 06, 2007 12:43 pm |
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I just did some testing between two 18F452's, with the Ex_Slave.c code
in one, and my Master test code in the other.
The Slave has to run at a minimum of 8 MHz for it to work.
The CCS file, Ex_Slave.c has the slave running at 20 MHz.
You've reduce it to 4 MHz. So, I think that's the problem. |
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rnielsen
Joined: 23 Sep 2003
Posts: 852
Location: Utah
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| Posted: Mon Aug 06, 2007 2:45 pm |
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The slave needs a certain amount of time to respond to the I2C bus commands. It's most likely that the master is sending each command faster than the slave can react to them. Try placing delays after each command, in the master code, and see if that gets things talking.
If you have a scope, very helpful in this type of situation, monitor the I2C bus and an unused pin of the slave. Have that pin pulsed while inside of the ISR of the slave. This will let you know how the slave's timing corresponds with the master's commands. I had a similar problem and needed to slow the master down enough for the slave to have time to process the ISR.
Ronald |
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AdamkT1
Joined: 21 Apr 2007
Posts: 44
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| Posted: Tue Aug 07, 2007 2:55 am |
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I appreciate your help and the pains you people have to take for me.
Thank you all.
The conditions are the same here and no change in the output so far.
On PIN_C7 I get two types of pulse trains, I shall try to describe them with respect to SCL :
1)-5V at PIN_C7 at t=40ms (relative to SCL) and remains low for 80ms and the go up at t=120ms
2)-5V at PIN_C7 at t=40ms (relative to SCL) and remains low for 40ms and go up at t=80ms
SCL =-5v at t=0 and remains for 40ms,0v at t=0+40ms,-5v at t=0+40 and remains there until t=0+40ms+40ms,0V at t=0+40ms+40ms,-5v at t=0+40ms+40ms and remains there until t=0+40ms+40ms+40ms and then transitions to 0V.
The Slave Code:
# | Code: | include <18F452.h>
#fuses HS,NOWDT,NOPROTECT,NOLVP
#use delay(clock=8000000)
//!#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)
#use i2c(SLAVE, SDA=PIN_C4, SCL=PIN_C3, address=0xa0)
BYTE address, buffer[0x10];
int8 Flg;
#INT_SSP
void ssp_interupt ()
{
BYTE incoming, state;
state = i2c_isr_state();
if(state < 0x80) //Master is sending data
{
incoming = i2c_read();
if(state == 1) //First received byte is address
address = incoming;
if(state == 2) //Second received byte is data
buffer[address] = incoming;
}
if(state == 0x80) //Master is requesting data
{
i2c_write(buffer[address]);
}
if (Flg==0)
{
output_low(PIN_C7);
}
else
output_high(PIN_C7);
Flg=~Flg;
}
void main ()
{
enable_interrupts(GLOBAL);
enable_interrupts(INT_SSP);
while (TRUE) ;
} |
Master code is:
| Code: | #include "18F452.h"
#fuses XT, NOWDT, PROTECT, BROWNOUT, PUT, NOLVP
#use delay(clock=8000000)
#use i2c(Master, sda=PIN_C4, scl=PIN_C3,slow)
#use fast_io(A)
#use fast_io(B)
//!#use fast_io(C)
#use fast_io(D)
#use fast_io(E)
//====================================
void main()
{
int8 data;
SET_TRIS_A(0);
SET_TRIS_B(0);
SET_TRIS_D(0);
SET_TRIS_E(0);
PORTA=0;
PORTB=0;
PORTC=0;
PORTD=0;
PORTE=0;
delay_ms(500);
while(TRUE)
{
// Write the letter 'B' to the slave board.
i2c_start();
i2c_write(0xA0);
i2c_write(0x00);
i2c_write('B');
i2c_stop();
// Read from the slave board and display the data.
i2c_start();
i2c_write(0xA0);
i2c_write(0x00);
i2c_start();
i2c_write(0xA1);
data = i2c_read(0);
i2c_stop();
PORTD='B';
PORTB=data;
}
} |
The 18F452 header file:
| Code: | #define PIN_A0 31744
#define PIN_A1 31745
#define PIN_A2 31746
#define PIN_A3 31747
#define PIN_A4 31748
#define PIN_A5 31749
#define PIN_A6 31750
#define PIN_B0 31752
#define PIN_B1 31753
#define PIN_B2 31754
#define PIN_B3 31755
#define PIN_B4 31756
#define PIN_B5 31757
#define PIN_B6 31758
#define PIN_B7 31759
#define PIN_C0 31760
#define PIN_C1 31761
#define PIN_C2 31762
#define PIN_C3 31763
#define PIN_C4 31764
#define PIN_C5 31765
#define PIN_C6 31766
#define PIN_C7 31767
#define PIN_D0 31768
#define PIN_D1 31769
#define PIN_D2 31770
#define PIN_D3 31771
#define PIN_D4 31772
#define PIN_D5 31773
#define PIN_D6 31774
#define PIN_D7 31775
#define PIN_E0 31776
#define PIN_E1 31777
#define PIN_E2 31778
////////////////////////////////////////////////////////////////// Useful defines
#define FALSE 0
#define TRUE 1
#define BYTE int
#define BOOLEAN short int
#define getc getch
#define fgetc getch
#define getchar getch
#define putc putchar
#define fputc putchar
#define fgets gets
#define fputs puts
////////////////////////////////////////////////////////////////// Control
// Control Functions: RESET_CPU(), SLEEP(), RESTART_CAUSE()
// Constants returned from RESTART_CAUSE() are:
#define WDT_TIMEOUT 7
#define MCLR_FROM_SLEEP 11
#define MCLR_FROM_RUN 15
#define NORMAL_POWER_UP 12
#define BROWNOUT_RESTART 14
#define WDT_FROM_SLEEP 3
#define RESET_INSTRUCTION 0
////////////////////////////////////////////////////////////////// Timer 0
// Timer 0 (AKA RTCC)Functions: SETUP_COUNTERS() or SETUP_TIMER_0(),
// SET_TIMER0() or SET_RTCC(),
// GET_TIMER0() or GET_RTCC()
// Constants used for SETUP_TIMER_0() are:
#define RTCC_INTERNAL 0
#define RTCC_EXT_L_TO_H 32
#define RTCC_EXT_H_TO_L 48
#define RTCC_DIV_1 8
#define RTCC_DIV_2 0
#define RTCC_DIV_4 1
#define RTCC_DIV_8 2
#define RTCC_DIV_16 3
#define RTCC_DIV_32 4
#define RTCC_DIV_64 5
#define RTCC_DIV_128 6
#define RTCC_DIV_256 7
#define RTCC_OFF 0x80
#define RTCC_8_BIT 0x40
// Constants used for SETUP_COUNTERS() are the above
// constants for the 1st param and the following for
// the 2nd param:
////////////////////////////////////////////////////////////////// WDT
// Watch Dog Timer Functions: SETUP_WDT() or SETUP_COUNTERS() (see above)
// RESTART_WDT()
//
#define WDT_ON 0x100
#define WDT_OFF 0
////////////////////////////////////////////////////////////////// Timer 1
// Timer 1 Functions: SETUP_TIMER_1, GET_TIMER1, SET_TIMER1
// Constants used for SETUP_TIMER_1() are:
// (or (via |) together constants from each group)
#define T1_DISABLED 0
#define T1_INTERNAL 0x85
#define T1_EXTERNAL 0x87
#define T1_EXTERNAL_SYNC 0x83
#define T1_CLK_OUT 8
#define T1_DIV_BY_1 0
#define T1_DIV_BY_2 0x10
#define T1_DIV_BY_4 0x20
#define T1_DIV_BY_8 0x30
////////////////////////////////////////////////////////////////// Timer 2
// Timer 2 Functions: SETUP_TIMER_2, GET_TIMER2, SET_TIMER2
// Constants used for SETUP_TIMER_2() are:
#define T2_DISABLED 0
#define T2_DIV_BY_1 4
#define T2_DIV_BY_4 5
#define T2_DIV_BY_16 6
////////////////////////////////////////////////////////////////// Timer 3
// Timer 3 Functions: SETUP_TIMER_3, GET_TIMER3, SET_TIMER3
// Constants used for SETUP_TIMER_3() are:
// (or (via |) together constants from each group)
#define T3_DISABLED 0
#define T3_INTERNAL 0x85
#define T3_EXTERNAL 0x87
#define T3_EXTERNAL_SYNC 0x83
#define T3_DIV_BY_1 0
#define T3_DIV_BY_2 0x10
#define T3_DIV_BY_4 0x20
#define T3_DIV_BY_8 0x30
////////////////////////////////////////////////////////////////// CCP
// CCP Functions: SETUP_CCPx, SET_PWMx_DUTY
// CCP Variables: CCP_x, CCP_x_LOW, CCP_x_HIGH
// Constants used for SETUP_CCPx() are:
#define CCP_OFF 0
#define CCP_CAPTURE_FE 4
#define CCP_CAPTURE_RE 5
#define CCP_CAPTURE_DIV_4 6
#define CCP_CAPTURE_DIV_16 7
#define CCP_COMPARE_SET_ON_MATCH 8
#define CCP_COMPARE_CLR_ON_MATCH 9
#define CCP_COMPARE_INT 0xA
#define CCP_COMPARE_INT_AND_TOGGLE 0x2
#define CCP_COMPARE_RESET_TIMER 0xB
#define CCP_PWM 0xC
#define CCP_PWM_PLUS_1 0x1c
#define CCP_PWM_PLUS_2 0x2c
#define CCP_PWM_PLUS_3 0x3c
#define CCP_USE_TIMER3 0x100
long CCP_1;
#byte CCP_1 = 0xfbe
#byte CCP_1_LOW= 0xfbe
#byte CCP_1_HIGH= 0xfbf
long CCP_2;
#byte CCP_2 = 0xfbb
#byte CCP_2_LOW= 0xfbb
#byte CCP_2_HIGH= 0xfbc
////////////////////////////////////////////////////////////////// PSP
// PSP Functions: SETUP_PSP, PSP_INPUT_FULL(), PSP_OUTPUT_FULL(),
// PSP_OVERFLOW(), INPUT_D(), OUTPUT_D()
// PSP Variables: PSP_DATA
// Constants used in SETUP_PSP() are:
#define PSP_ENABLED 0x10
#define PSP_DISABLED 0
#byte PSP_DATA= 0xF83
////////////////////////////////////////////////////////////////// SPI
// SPI Functions: SETUP_SPI, SPI_WRITE, SPI_READ, SPI_DATA_IN
// Constants used in SETUP_SPI() are:
#define SPI_MASTER 0x20
#define SPI_SLAVE 0x24
#define SPI_L_TO_H 0
#define SPI_H_TO_L 0x10
#define SPI_CLK_DIV_4 0
#define SPI_CLK_DIV_16 1
#define SPI_CLK_DIV_64 2
#define SPI_CLK_T2 3
#define SPI_SS_DISABLED 1
#define SPI_SAMPLE_AT_END 0x8000
#define SPI_XMIT_L_TO_H 0x4000
////////////////////////////////////////////////////////////////// UART
// Constants used in setup_uart() are:
// FALSE - Turn UART off
// TRUE - Turn UART on
#define UART_ADDRESS 2
#define UART_DATA 4
////////////////////////////////////////////////////////////////// VREF
// Constants used in setup_low_volt_detect() are:
//
#define LVD_LVDIN 0x1F
#define LVD_46 0x1E
#define LVD_43 0x1D
#define LVD_41 0x1C
#define LVD_40 0x1B
#define LVD_37 0x1A
#define LVD_36 0x19
#define LVD_34 0x18
#define LVD_31 0x17
#define LVD_29 0x16
#define LVD_28 0x15
#define LVD_26 0x14
#define LVD_25 0x13
#define LVD_23 0x12
#define LVD_21 0x11
////////////////////////////////////////////////////////////////// INTERNAL RC
// Constants used in setup_oscillator() are:
#define OSC_TIMER1 1
#define OSC_NORMAL 0
////////////////////////////////////////////////////////////////// ADC
// ADC Functions: SETUP_ADC(), SETUP_ADC_PORTS() (aka SETUP_PORT_A),
// SET_ADC_CHANNEL(), READ_ADC()
// Constants used for SETUP_ADC() are:
#define ADC_OFF 0 // ADC Off
#define ADC_CLOCK_DIV_2 0x10000
#define ADC_CLOCK_DIV_4 0x4000
#define ADC_CLOCK_DIV_8 0x0040
#define ADC_CLOCK_DIV_16 0x4040
#define ADC_CLOCK_DIV_32 0x0080
#define ADC_CLOCK_DIV_64 0x4080
#define ADC_CLOCK_INTERNAL 0x00c0 // Internal 2-6us
// Constants used in SETUP_ADC_PORTS() are:
#define NO_ANALOGS 7 // None
#define ALL_ANALOG 0 // A0 A1 A2 A3 A5 E0 E1 E2
#define AN0_AN1_AN2_AN4_AN5_AN6_AN7_VSS_VREF 1 // A0 A1 A2 A5 E0 E1 E2 VRefh=A3
#define AN0_AN1_AN2_AN3_AN4 2 // A0 A1 A2 A3 A5
#define AN0_AN1_AN2_AN4_VSS_VREF 3 // A0 A1 A2 A5 VRefh=A3
#define AN0_AN1_AN3 4 // A0 A1 A3
#define AN0_AN1_VSS_VREF 5 // A0 A1 VRefh=A3
#define AN0_AN1_AN4_AN5_AN6_AN7_VREF_VREF 0x08 // A0 A1 A5 E0 E1 E2 VRefh=A3 VRefl=A2
#define AN0_AN1_AN2_AN3_AN4_AN5 0x09 // A0 A1 A2 A3 A5 E0
#define AN0_AN1_AN2_AN4_AN5_VSS_VREF 0x0A // A0 A1 A2 A5 E0 VRefh=A3
#define AN0_AN1_AN4_AN5_VREF_VREF 0x0B // A0 A1 A5 E0 VRefh=A3 VRefl=A2
#define AN0_AN1_AN4_VREF_VREF 0x0C // A0 A1 A5 VRefh=A3 VRefl=A2
#define AN0_AN1_VREF_VREF 0x0D // A0 A1 VRefh=A3 VRefl=A2
#define AN0 0x0E // A0
#define AN0_VREF_VREF 0x0F // A0 VRefh=A3 VRefl=A2
#define ANALOG_RA3_REF 0x1 //!old only provided for compatibility
#define A_ANALOG 0x2 //!old only provided for compatibility
#define A_ANALOG_RA3_REF 0x3 //!old only provided for compatibility
#define RA0_RA1_RA3_ANALOG 0x4 //!old only provided for compatibility
#define RA0_RA1_ANALOG_RA3_REF 0x5 //!old only provided for compatibility
#define ANALOG_RA3_RA2_REF 0x8 //!old only provided for compatibility
#define ANALOG_NOT_RE1_RE2 0x9 //!old only provided for compatibility
#define ANALOG_NOT_RE1_RE2_REF_RA3 0xA //!old only provided for compatibility
#define ANALOG_NOT_RE1_RE2_REF_RA3_RA2 0xB //!old only provided for compatibility
#define A_ANALOG_RA3_RA2_REF 0xC //!old only provided for compatibility
#define RA0_RA1_ANALOG_RA3_RA2_REF 0xD //!old only provided for compatibility
#define RA0_ANALOG 0xE //!old only provided for compatibility
#define RA0_ANALOG_RA3_RA2_REF 0xF //!old only provided for compatibility
// Constants used in READ_ADC() are:
#define ADC_START_AND_READ 7 // This is the default if nothing is specified
#define ADC_START_ONLY 1
#define ADC_READ_ONLY 6
////////////////////////////////////////////////////////////////// INT
// Interrupt Functions: ENABLE_INTERRUPTS(), DISABLE_INTERRUPTS(),
// EXT_INT_EDGE()
//
// Constants used in EXT_INT_EDGE() are:
#define L_TO_H 0x40
#define H_TO_L 0
// Constants used in ENABLE/DISABLE_INTERRUPTS() are:
#define GLOBAL 0xF2C0
#define INT_RTCC 0xF220
#define INT_TIMER0 0xF220
#define INT_TIMER1 0x9D01
#define INT_TIMER2 0x9D02
#define INT_TIMER3 0xA002
#define INT_EXT 0xF210
#define INT_EXT1 0xF008
#define INT_EXT2 0xF010
#define INT_RB 0xFFF208
#define INT_PSP 0x9D80
#define INT_AD 0x9D40
#define INT_RDA 0x9D20
#define INT_TBE 0x9D10
#define INT_SSP 0x9D08
#define INT_CCP1 0x9D04
#define INT_CCP2 0xA001
#define INT_BUSCOL 0xA008
#define INT_LOWVOLT 0xA004
#define INT_EEPROM 0xA010
#byte TMR0 = 0x01
#byte PCL = 0x02
#byte STATUS = 0x03
#byte FSR = 0x04
#byte PORTA = 0xF80
#byte PORTB = 0xF81
#byte PORTC = 0xF82
#byte PORTD = 0xF83
#byte PORTE = 0xF84
#byte PCLATH= 0x0a
#byte INTCON3= 0xFF0
#byte INTCON2= 0xFF1
#byte INTCON = 0xFF2
#byte TRISA = 0xF92
#byte TRISB = 0xF93
#byte TRISC = 0xF94
#byte TRISD = 0xF95
#byte TRISE = 0xF96
#list |
I have tried delays between the write functions but get the same result, that is PORTB remains at 0x00 all the time |
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ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
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| Posted: Tue Aug 07, 2007 6:49 am |
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- Again, what is your compiler version?
- In the master code you have fuse XT for 8MHz. For stable operation change this to the HS fuse.
- One important difference between your code and extee.c is that the example code is testing the slave to be ready before transmitting new commands to the slave. You don't do this test.
- It is bad programming practice to modify the processor include file as supplied with your compiler. In the situation where you ever would upgrade to another compiler version there is a good chance that the include file changes as well, now you are going to miss these changes with undefined behavior as a result. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Tue Aug 07, 2007 1:45 pm |
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1. Are you testing this in hardware, or is this being done in Proteus ?
2. The lines shown in bold below are incorrect for the 18F452.
| Quote: | #byte TMR0 = 0x01
#byte PCL = 0x02
#byte STATUS = 0x03
#byte FSR = 0x04
#byte PORTA = 0xF80
#byte PORTB = 0xF81
#byte PORTC = 0xF82
#byte PORTD = 0xF83
#byte PORTE = 0xF84
#byte PCLATH= 0x0a
#byte INTCON3= 0xFF0
#byte INTCON2= 0xFF1
#byte INTCON = 0xFF2
#byte TRISA = 0xF92
#byte TRISB = 0xF93
#byte TRISC = 0xF94
#byte TRISD = 0xF95
#byte TRISE = 0xF96 |
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AdamkT1
Joined: 21 Apr 2007
Posts: 44
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| Posted: Tue Aug 07, 2007 6:25 pm |
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I am testing it in PROTEUS. I am sorry for not mentioning.
Thank you very much. |
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