16f877 internal eeprom

[Chris_1982]

HI all
I am trying to write to the internal EEPROM memory on my PIC16f877 (at the moment i am only using MPLAB simulator). I can read the data but not write. When i try to run my program the read works fine then the write brings up the program memory window.
Any suggestions as to what i am doing wrong?
I have copied my program below.
Another question i have is can you write/read the 32bit float numbers??

cheers chris


#DEVICE PIC16F877
#include "C:\Program Files\PICC\Chris programs\eeprom.h"


void main() {
int x,ad,y;
float airspeed;
#byte Float_airspeed = airspeed;

setup_adc_ports(NO_ANALOGS);
setup_adc(ADC_CLOCK_DIV_2);
setup_spi(FALSE);
setup_psp(PSP_DISABLED);
setup_counters(RTCC_INTERNAL,RTCC_DIV_2);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
setup_ccp1(CCP_OFF);
setup_ccp2(CCP_OFF);

ad=02;
x=16;
airspeed=28.523;
y=read_eeprom(ad);
write_eeprom(ad,x);
___________________________
This message was ported from CCS's old forum
Original Post ID: 11420

[Rod Ladwig]

:=HI all
:=I am trying to write to the internal EEPROM memory on my PIC16f877 (at the moment i am only using MPLAB simulator). I can read the data but not write. When i try to run my program the read works fine then the write brings up the program memory window.
:=Any suggestions as to what i am doing wrong?
:=I have copied my program below.
:=Another question i have is can you write/read the 32bit float numbers??
:=
:=cheers chris
:=
:=
:=#DEVICE PIC16F877
:=#include "C:\Program Files\PICC\Chris programs\eeprom.h"
:=
:=
:=void main() {
:= int x,ad,y;
:= float airspeed;
:= #byte Float_airspeed = airspeed;
:=
:= setup_adc_ports(NO_ANALOGS);
:= setup_adc(ADC_CLOCK_DIV_2);
:= setup_spi(FALSE);
:= setup_psp(PSP_DISABLED);
:= setup_counters(RTCC_INTERNAL,RTCC_DIV_2);
:= setup_timer_1(T1_DISABLED);
:= setup_timer_2(T2_DISABLED,0,1);
:= setup_ccp1(CCP_OFF);
:= setup_ccp2(CCP_OFF);
:=
:= ad=02;
:= x=16;
:= airspeed=28.523;
:= y=read_eeprom(ad);
:= write_eeprom(ad,x);


/*******************************************************************************/
/* function
/* Read and write 4 bytes to EEProm
/*******************************************************************************/
// n is an offset into the eeprom. For floats
// you must increment it by 4. For example if
// the first float is at 0 the second one should
// be at 4 and the third at 8.

void WRITE_FLOAT_EEPROM(long int n, float data) {
int i;

for (i = 0; i < 4; i++)
write_eeprom(i + n, *(&data + i) ) ;
}

float READ_FLOAT_EEPROM(long int n) {
int i;
float data;

for (i = 0; i < 4; i++)
*(&data + i) = read_eeprom(i + n);

return(data);
}
___________________________
This message was ported from CCS's old forum
Original Post ID: 11422

[Chris_1982]

Thanks for that code Rod thats realy useful I can now read float numbers.
BUT i still can not write values to the memory.
Do you or anyone else out there know whether i should be able to use the MPLAB simulator to run this code and see the results in the EEPROM memory window? (I know that i could when i have produced the equivalent code in assembly )
Thanks again
Chris


:=:=HI all
:=:=I am trying to write to the internal EEPROM memory on my PIC16f877 (at the moment i am only using MPLAB simulator). I can read the data but not write. When i try to run my program the read works fine then the write brings up the program memory window.
:=:=Any suggestions as to what i am doing wrong?
:=:=I have copied my program below.
:=:=Another question i have is can you write/read the 32bit float numbers??
:=:=
:=:=cheers chris
:=:=
:=:=
:=:=#DEVICE PIC16F877
:=:=#include "C:\Program Files\PICC\Chris programs\eeprom.h"
:=:=
:=:=
:=:=void main() {
:=:= int x,ad,y;
:=:= float airspeed;
:=:= #byte Float_airspeed = airspeed;
:=:=
:=:= setup_adc_ports(NO_ANALOGS);
:=:= setup_adc(ADC_CLOCK_DIV_2);
:=:= setup_spi(FALSE);
:=:= setup_psp(PSP_DISABLED);
:=:= setup_counters(RTCC_INTERNAL,RTCC_DIV_2);
:=:= setup_timer_1(T1_DISABLED);
:=:= setup_timer_2(T2_DISABLED,0,1);
:=:= setup_ccp1(CCP_OFF);
:=:= setup_ccp2(CCP_OFF);
:=:=
:=:= ad=02;
:=:= x=16;
:=:= airspeed=28.523;
:=:= y=read_eeprom(ad);
:=:= write_eeprom(ad,x);
:=
:=
:=/*******************************************************************************/
:=/* function
:=/* Read and write 4 bytes to EEProm
:=/*******************************************************************************/
:=// n is an offset into the eeprom. For floats
:=// you must increment it by 4. For example if
:=// the first float is at 0 the second one should
:=// be at 4 and the third at 8.
:=
:=void WRITE_FLOAT_EEPROM(long int n, float data) {
:= int i;
:=
:= for (i = 0; i < 4; i++)
:= write_eeprom(i + n, *(&data + i) ) ;
:=}
:=
:=float READ_FLOAT_EEPROM(long int n) {
:= int i;
:= float data;
:=
:= for (i = 0; i < 4; i++)
:= *(&data + i) = read_eeprom(i + n);
:=
:= return(data);
:=}
___________________________
This message was ported from CCS's old forum
Original Post ID: 11423

[Shane Rowell]

I am away from my office, but one thing comes to mind. Have you enabled the fuse that allows for EE write?

Shane


:=Thanks for that code Rod thats realy useful I can now read float numbers.
:=BUT i still can not write values to the memory.
:=Do you or anyone else out there know whether i should be able to use the MPLAB simulator to run this code and see the results in the EEPROM memory window? (I know that i could when i have produced the equivalent code in assembly )
:=Thanks again
:=Chris
:=
:=
:=:=:=HI all
:=:=:=I am trying to write to the internal EEPROM memory on my PIC16f877 (at the moment i am only using MPLAB simulator). I can read the data but not write. When i try to run my program the read works fine then the write brings up the program memory window.
:=:=:=Any suggestions as to what i am doing wrong?
:=:=:=I have copied my program below.
:=:=:=Another question i have is can you write/read the 32bit float numbers??
:=:=:=
:=:=:=cheers chris
:=:=:=
:=:=:=
:=:=:=#DEVICE PIC16F877
:=:=:=#include "C:\Program Files\PICC\Chris programs\eeprom.h"
:=:=:=
:=:=:=
:=:=:=void main() {
:=:=:= int x,ad,y;
:=:=:= float airspeed;
:=:=:= #byte Float_airspeed = airspeed;
:=:=:=
:=:=:= setup_adc_ports(NO_ANALOGS);
:=:=:= setup_adc(ADC_CLOCK_DIV_2);
:=:=:= setup_spi(FALSE);
:=:=:= setup_psp(PSP_DISABLED);
:=:=:= setup_counters(RTCC_INTERNAL,RTCC_DIV_2);
:=:=:= setup_timer_1(T1_DISABLED);
:=:=:= setup_timer_2(T2_DISABLED,0,1);
:=:=:= setup_ccp1(CCP_OFF);
:=:=:= setup_ccp2(CCP_OFF);
:=:=:=
:=:=:= ad=02;
:=:=:= x=16;
:=:=:= airspeed=28.523;
:=:=:= y=read_eeprom(ad);
:=:=:= write_eeprom(ad,x);
:=:=
:=:=
:=:=/*******************************************************************************/
:=:=/* function
:=:=/* Read and write 4 bytes to EEProm
:=:=/*******************************************************************************/
:=:=// n is an offset into the eeprom. For floats
:=:=// you must increment it by 4. For example if
:=:=// the first float is at 0 the second one should
:=:=// be at 4 and the third at 8.
:=:=
:=:=void WRITE_FLOAT_EEPROM(long int n, float data) {
:=:= int i;
:=:=
:=:= for (i = 0; i < 4; i++)
:=:= write_eeprom(i + n, *(&data + i) ) ;
:=:=}
:=:=
:=:=float READ_FLOAT_EEPROM(long int n) {
:=:= int i;
:=:= float data;
:=:=
:=:= for (i = 0; i < 4; i++)
:=:= *(&data + i) = read_eeprom(i + n);
:=:=
:=:= return(data);
:=:=}
___________________________
This message was ported from CCS's old forum
Original Post ID: 11432

[chris_1982]

I have now checked the program running on the PIC as well as the sim and niether work!! I have tried both with the statement #FUSES NOCPD.

What am I doing wrong ????

cheers chris



:=I am away from my office, but one thing comes to mind. Have you enabled the fuse that allows for EE write?
:=
:=Shane
:=
:=
:=:=Thanks for that code Rod thats realy useful I can now read float numbers.
:=:=BUT i still can not write values to the memory.
:=:=Do you or anyone else out there know whether i should be able to use the MPLAB simulator to run this code and see the results in the EEPROM memory window? (I know that i could when i have produced the equivalent code in assembly )
:=:=Thanks again
:=:=Chris
:=:=
:=:=
:=:=:=:=HI all
:=:=:=:=I am trying to write to the internal EEPROM memory on my PIC16f877 (at the moment i am only using MPLAB simulator). I can read the data but not write. When i try to run my program the read works fine then the write brings up the program memory window.
:=:=:=:=Any suggestions as to what i am doing wrong?
:=:=:=:=I have copied my program below.
:=:=:=:=Another question i have is can you write/read the 32bit float numbers??
:=:=:=:=
:=:=:=:=cheers chris
:=:=:=:=
:=:=:=:=
:=:=:=:=#DEVICE PIC16F877
:=:=:=:=#include "C:\Program Files\PICC\Chris programs\eeprom.h"
:=:=:=:=
:=:=:=:=
:=:=:=:=void main() {
:=:=:=:= int x,ad,y;
:=:=:=:= float airspeed;
:=:=:=:= #byte Float_airspeed = airspeed;
:=:=:=:=
:=:=:=:= setup_adc_ports(NO_ANALOGS);
:=:=:=:= setup_adc(ADC_CLOCK_DIV_2);
:=:=:=:= setup_spi(FALSE);
:=:=:=:= setup_psp(PSP_DISABLED);
:=:=:=:= setup_counters(RTCC_INTERNAL,RTCC_DIV_2);
:=:=:=:= setup_timer_1(T1_DISABLED);
:=:=:=:= setup_timer_2(T2_DISABLED,0,1);
:=:=:=:= setup_ccp1(CCP_OFF);
:=:=:=:= setup_ccp2(CCP_OFF);
:=:=:=:=
:=:=:=:= ad=02;
:=:=:=:= x=16;
:=:=:=:= airspeed=28.523;
:=:=:=:= y=read_eeprom(ad);
:=:=:=:= write_eeprom(ad,x);
:=:=:=
:=:=:=
:=:=:=/*******************************************************************************/
:=:=:=/* function
:=:=:=/* Read and write 4 bytes to EEProm
:=:=:=/*******************************************************************************/
:=:=:=// n is an offset into the eeprom. For floats
:=:=:=// you must increment it by 4. For example if
:=:=:=// the first float is at 0 the second one should
:=:=:=// be at 4 and the third at 8.
:=:=:=
:=:=:=void WRITE_FLOAT_EEPROM(long int n, float data) {
:=:=:= int i;
:=:=:=
:=:=:= for (i = 0; i < 4; i++)
:=:=:= write_eeprom(i + n, *(&data + i) ) ;
:=:=:=}
:=:=:=
:=:=:=float READ_FLOAT_EEPROM(long int n) {
:=:=:= int i;
:=:=:= float data;
:=:=:=
:=:=:= for (i = 0; i < 4; i++)
:=:=:= *(&data + i) = read_eeprom(i + n);
:=:=:=
:=:=:= return(data);
:=:=:=}
___________________________
This message was ported from CCS's old forum
Original Post ID: 11470

[Nigel Steed]

Hi Chris,

I have had this too, and contacted CCS. I was using compiler version 2.13 and they said it was very old and not stable. They suggested upgrading to version 3.13 and now all is well.

Best Wishes

Nigel
___________________________
This message was ported from CCS's old forum
Original Post ID: 11474

[Nigel Steed]

Hi Chris,

I had the same thing, and contacted CCS about it. They said I was using an old compiler version ( 2.13 ) and they suggested upgrading to the latest version. This has now cured the problem.

Hope this helps

Best Regards

Nigel

:=I have now checked the program running on the PIC as well as the sim and niether work!! I have tried both with the statement #FUSES NOCPD.
:=
:=What am I doing wrong ????
:=
:=cheers chris
:=
:=
:=
:=:=I am away from my office, but one thing comes to mind. Have you enabled the fuse that allows for EE write?
:=:=
:=:=Shane
:=:=
:=:=
:=:=:=Thanks for that code Rod thats realy useful I can now read float numbers.
:=:=:=BUT i still can not write values to the memory.
:=:=:=Do you or anyone else out there know whether i should be able to use the MPLAB simulator to run this code and see the results in the EEPROM memory window? (I know that i could when i have produced the equivalent code in assembly )
:=:=:=Thanks again
:=:=:=Chris
:=:=:=
:=:=:=
:=:=:=:=:=HI all
:=:=:=:=:=I am trying to write to the internal EEPROM memory on my PIC16f877 (at the moment i am only using MPLAB simulator). I can read the data but not write. When i try to run my program the read works fine then the write brings up the program memory window.
:=:=:=:=:=Any suggestions as to what i am doing wrong?
:=:=:=:=:=I have copied my program below.
:=:=:=:=:=Another question i have is can you write/read the 32bit float numbers??
:=:=:=:=:=
:=:=:=:=:=cheers chris
:=:=:=:=:=
:=:=:=:=:=
:=:=:=:=:=#DEVICE PIC16F877
:=:=:=:=:=#include "C:\Program Files\PICC\Chris programs\eeprom.h"
:=:=:=:=:=
:=:=:=:=:=
:=:=:=:=:=void main() {
:=:=:=:=:= int x,ad,y;
:=:=:=:=:= float airspeed;
:=:=:=:=:= #byte Float_airspeed = airspeed;
:=:=:=:=:=
:=:=:=:=:= setup_adc_ports(NO_ANALOGS);
:=:=:=:=:= setup_adc(ADC_CLOCK_DIV_2);
:=:=:=:=:= setup_spi(FALSE);
:=:=:=:=:= setup_psp(PSP_DISABLED);
:=:=:=:=:= setup_counters(RTCC_INTERNAL,RTCC_DIV_2);
:=:=:=:=:= setup_timer_1(T1_DISABLED);
:=:=:=:=:= setup_timer_2(T2_DISABLED,0,1);
:=:=:=:=:= setup_ccp1(CCP_OFF);
:=:=:=:=:= setup_ccp2(CCP_OFF);
:=:=:=:=:=
:=:=:=:=:= ad=02;
:=:=:=:=:= x=16;
:=:=:=:=:= airspeed=28.523;
:=:=:=:=:= y=read_eeprom(ad);
:=:=:=:=:= write_eeprom(ad,x);
:=:=:=:=
:=:=:=:=
:=:=:=:=/*******************************************************************************/
:=:=:=:=/* function
:=:=:=:=/* Read and write 4 bytes to EEProm
:=:=:=:=/*******************************************************************************/
:=:=:=:=// n is an offset into the eeprom. For floats
:=:=:=:=// you must increment it by 4. For example if
:=:=:=:=// the first float is at 0 the second one should
:=:=:=:=// be at 4 and the third at 8.
:=:=:=:=
:=:=:=:=void WRITE_FLOAT_EEPROM(long int n, float data) {
:=:=:=:= int i;
:=:=:=:=
:=:=:=:= for (i = 0; i < 4; i++)
:=:=:=:= write_eeprom(i + n, *(&data + i) ) ;
:=:=:=:=}
:=:=:=:=
:=:=:=:=float READ_FLOAT_EEPROM(long int n) {
:=:=:=:= int i;
:=:=:=:= float data;
:=:=:=:=
:=:=:=:= for (i = 0; i < 4; i++)
:=:=:=:= *(&data + i) = read_eeprom(i + n);
:=:=:=:=
:=:=:=:= return(data);
:=:=:=:=}
___________________________
This message was ported from CCS's old forum
Original Post ID: 11522