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Dario
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| Writing eeprom isn't working for me. |
 Posted: Tue Nov 15, 2005 10:16 pm |
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I am trying to write a data table to eeprom on the 16F873A. I would like the device to perform and A to D (8-bit) on A0, and pull data out of the resultant eeprom address. The data is then output to the ports as a 3 bit decimal number.
This code was working and displaying the A-D conversion.
| Code: | #include <16F873A.h>
#device adc=8
#fuses NOWDT,HS, NOPUT, NOPROTECT, NODEBUG, BROWNOUT, NOLVP, NOCPD, NOWRT
#use delay(clock=4000000)
void main()
{
int value, hunten, hund, tens, ones;
setup_adc_ports(AN0_AN1_VSS_VREF); //VREF = A3
setup_adc(ADC_CLOCK_INTERNAL);
setup_spi(FALSE);
setup_timer_0(RTCC_INTERNAL|RTCC_DIV_1);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
setup_comparator(NC_NC_NC_NC);
setup_vref(FALSE);
set_tris_b(0x00);
set_tris_c(0x00);
set_adc_channel(0);
while ( TRUE )
{
value = read_adc();
hund = value / 100;
value = value % 100;
tens = value / 10;
ones = value % 10;
hunten = 16*hund + tens;
output_b(hunten);
output_c(ones);
delay_ms(2000);
}
}
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I then tried to create the eeprom lookup table and i get only 0's on the output. I know there must be easier ways but i thaught this might work.
| Code: |
#include <16F873A.h>
#device adc=8
#fuses NOWDT,HS, NOPUT, NOPROTECT, NODEBUG, BROWNOUT, NOLVP, NOCPD, NOWRT
#use delay(clock=4000000)
void main()
{
int data, value, hunten, hund, tens, ones;
setup_adc_ports(AN0_AN1_VSS_VREF); //VREF = A3
setup_adc(ADC_CLOCK_INTERNAL);
setup_spi(FALSE);
setup_timer_0(RTCC_INTERNAL|RTCC_DIV_1);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
setup_comparator(NC_NC_NC_NC);
setup_vref(FALSE);
set_tris_b(0x00);
set_tris_c(0x00);
set_adc_channel(0);
//***** WRITE DATA TABLE TO EEPROM******//
write_eeprom( 15 , 112 );
write_eeprom( 16 , 104 );
write_eeprom( 17 , 97 );
write_eeprom( 18 , 90 );
write_eeprom( 19 , 85 );
write_eeprom( 20 , 80 );
write_eeprom( 21 , 75 );
write_eeprom( 22 , 71 );
write_eeprom( 23 , 68 );
write_eeprom( 24 , 64 );
write_eeprom( 25 , 61 );
write_eeprom( 26 , 58 );
write_eeprom( 27 , 56 );
write_eeprom( 28 , 54 );
write_eeprom( 29 , 51 );
write_eeprom( 30 , 49 );
write_eeprom( 31 , 47 );
write_eeprom( 32 , 46 );
write_eeprom( 33 , 44 );
write_eeprom( 34 , 42 );
write_eeprom( 35 , 41 );
write_eeprom( 36 , 40 );
write_eeprom( 37 , 38 );
write_eeprom( 38 , 37 );
write_eeprom( 39 , 36 );
write_eeprom( 40 , 35 );
write_eeprom( 41 , 34 );
write_eeprom( 42 , 33 );
write_eeprom( 43 , 32 );
write_eeprom( 44 , 31 );
write_eeprom( 45 , 30 );
write_eeprom( 46 , 30 );
write_eeprom( 47 , 29 );
write_eeprom( 48 , 28 );
write_eeprom( 49 , 27 );
write_eeprom( 50 , 27 );
write_eeprom( 51 , 26 );
write_eeprom( 52 , 26 );
write_eeprom( 53 , 25 );
write_eeprom( 54 , 24 );
write_eeprom( 55 , 24 );
write_eeprom( 56 , 23 );
write_eeprom( 57 , 23 );
write_eeprom( 58 , 22 );
write_eeprom( 59 , 22 );
write_eeprom( 60 , 22 );
write_eeprom( 61 , 21 );
write_eeprom( 62 , 21 );
write_eeprom( 63 , 20 );
write_eeprom( 64 , 20 );
write_eeprom( 65 , 20 );
write_eeprom( 66 , 19 );
write_eeprom( 67 , 19 );
write_eeprom( 68 , 19 );
write_eeprom( 69 , 18 );
write_eeprom( 70 , 18 );
write_eeprom( 71 , 18 );
write_eeprom( 72 , 17 );
write_eeprom( 73 , 17 );
write_eeprom( 74 , 17 );
write_eeprom( 75 , 16 );
write_eeprom( 76 , 16 );
write_eeprom( 77 , 16 );
write_eeprom( 78 , 16 );
write_eeprom( 79 , 15 );
write_eeprom( 80 , 15 );
write_eeprom( 81 , 15 );
write_eeprom( 82 , 15 );
write_eeprom( 83 , 15 );
write_eeprom( 84 , 14 );
write_eeprom( 85 , 14 );
write_eeprom( 86 , 14 );
write_eeprom( 87 , 14 );
write_eeprom( 88 , 14 );
write_eeprom( 89 , 13 );
write_eeprom( 90 , 13 );
write_eeprom( 91 , 13 );
write_eeprom( 92 , 13 );
write_eeprom( 93 , 13 );
write_eeprom( 94 , 12 );
write_eeprom( 95 , 12 );
write_eeprom( 96 , 12 );
write_eeprom( 97 , 12 );
write_eeprom( 98 , 12 );
write_eeprom( 99 , 12 );
write_eeprom( 100 , 12 );
write_eeprom( 101 , 11 );
write_eeprom( 102 , 11 );
write_eeprom( 103 , 11 );
write_eeprom( 104 , 11 );
write_eeprom( 105 , 11 );
write_eeprom( 106 , 11 );
write_eeprom( 107 , 11 );
write_eeprom( 108 , 11 );
write_eeprom( 109 , 10 );
write_eeprom( 110 , 10 );
write_eeprom( 111 , 10 );
write_eeprom( 112 , 10 );
write_eeprom( 113 , 10 );
write_eeprom( 114 , 10 );
write_eeprom( 115 , 10 );
write_eeprom( 116 , 10 );
write_eeprom( 117 , 10 );
write_eeprom( 118 , 9 );
write_eeprom( 119 , 9 );
write_eeprom( 120 , 9 );
write_eeprom( 121 , 9 );
write_eeprom( 122 , 9 );
write_eeprom( 123 , 9 );
write_eeprom( 124 , 9 );
write_eeprom( 125 , 9 );
write_eeprom( 126 , 9 );
write_eeprom( 127 , 9 );
while ( TRUE )
{
data = read_adc();
value = read_eeprom(data);
hund = value / 100;
value = value % 100;
tens = value / 10;
ones = value % 10;
hunten = 16*hund + tens;
output_b(hunten);
output_c(ones);
delay_ms(2000);
}
}
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The compiler tells me out of ROM but the 16F873A has 128 bytes (8-bit) of eeprom. I then tried deleting until it worked. It would compile after everything lower than 80 is deleted and the says 51% full. makes me think it wants a hex address but i have read that decimal should be fine. If anyone has a solution or a way around this to get me reading off some sort of preprogrammed table with every A-D conversion the help would be great.
Thanks. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Tue Nov 15, 2005 11:19 pm |
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| Quote: | | The compiler tells me out of ROM but the 16F873A has 128 bytes (8-bit) of eeprom. |
ROM does not mean eeprom. It means the main program memory.
I compiled your program with PCM vs. 3.239 and it only used 190 words
of ROM and 14 bytes of RAM. I don't see how you can be running
out of ROM.
There are a few problems with your program. You're reading an 8-bit
value from the A/D, which can range from 0 to 255. Then you're
using that value as an index into eeprom which only exists at addresses
from 0 to 127. Also, you haven't initialized addresses 0 to 14 in the
eeprom.
You have enabled Vref on pin RA3. Are you applying a reference
voltage to that pin ?
If you want to have a lookup table, it would be a lot easier if you
put it in program memory instead of data eeprom. Then you can
initialize the table at compile-time, instead of at run-time as you are
doing. Example:
| Code: | #include <16F873A.H>
#fuses XT, NOWDT, NOPROTECT, BROWNOUT, PUT, NOLVP
#use delay(clock = 4000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7, ERRORS)
int8 const lookup_table[] =
{
0,1,2,3,4,5,6,7,8,9
10,11,12,13,14,15,16,17,18,19,
20,21,22,23,24,25,26,27,28,29,
30,31,32,33,34,35,36,37,38,39,
40,41,42,43,44,45,46,47,48,49,
50,51,52,53,54,55,56,57,58,59,
60,61,62,63,64,65,66,67,68,69,
70,71,72,73,74,75,76,77,78,79,
80,81,82,83,84,85,86,87,88,89,
90,91,92,93,94,95,96,97,98,99,
100,101,102,103,104,105,106,107,108,109,
110,111,112,113,114,115,116,117,118,119,
120,121,122,123,124,125,126,127
};
//======================================
void main()
{
int8 i;
// Display the lookup table.
for(i = 0; i < sizeof(lookup_table); i++)
printf("%u \n\r", lookup_table[i]);
while(1);
} |
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kender
Joined: 09 Aug 2004
Posts: 768
Location: Silicon Valley
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| Posted: Tue Nov 15, 2005 11:48 pm |
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Wow, it's the first time I see the lookup table in the EEPROM. It could be a neat trick for creating dynamic lookup table. I know I should probably read the datasheet for this (and I will), but how does the read time compare for the on-chip EEPROM, ROM and RAM?
Sincerely,
~K |
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Guest
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| Posted: Wed Nov 16, 2005 1:04 am |
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| Thanks I'll give the data table a go how you've suggested |
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