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Lcj100
Joined: 29 Nov 2008
Posts: 3
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| Programming problem |
 Posted: Mon Mar 02, 2009 10:34 am |
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I'm a final year student of BEE engineering. I'm having problems with my C programming. My purpose of this source code is to display the temperature in seven segment display once the temperature sensor LM35 detect the room temperature. I'm using CCS C compiler. Anyone familiar with this compiler? As a results when i burn this source code into PIC16f877. The seven segment will only display number 16 in seven segment display. Can i know what's wrong with this source code?
| Code: | #include<16f877.h>
#device adc=10
#use delay(clock=10000000)
#fuses hs, noprotect, nowdt, nolvp
#byte porta=5
#byte portb=6
#byte portd=8
int i;
int temp;
void main()
{
set_tris_d(0b00000000);
set_tris_b(0b00000000);
setup_port_a(RA0_analog);
setup_adc(adc_clock_internal);
do
{
set_adc_channel(0);
delay_ms(10);
temp=read_adc()/2;
if (temp=16)
{ portb=0b00000110;
portd=0b01111101; }
else if (temp=17)
{ portb=0b00000110;
portd=0b00000111; }
else if (temp=18)
{ portb=0b00000110;
portd=0b01111111; }
else if (temp=19)
{ portb=0b00000110;
portd=0b01101111; }
else if (temp=20)
{ portb=0b01011011;
portd=0b00111111; }
else if (temp=21)
{ portb=0b01011011;
portd=0b00000110; }
else if (temp=22)
{ portb=0b01011011;
portd=0b01011011; }
else if (temp=23)
{ portb=0b01011011;
portd=0b01001111; }
else if (temp=24)
{ portb=0b01011011;
portd=0b01100110; }
else if (temp=25)
{ portb=0b01011011;
portd=0b01101101; }
else if (temp=26)
{ portb=0b01011011;
portd=0b01111101; }
else if (temp=27)
{ portb=0b01011011;
portd=0b00000111; }
else if (temp=28)
{ portb=0b01011011;
portd=0b01111111; }
else if (temp=29)
{ portb=0b01011011;
portd=0b01101111; }
else if (temp=30)
{ portb=0b01001111;
portd=0b00111111; }
delay_ms(2000);
}while(1);
} |
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Ttelmah
Guest
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| Posted: Mon Mar 02, 2009 11:16 am |
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Start, by telling us how the 7segment is wired. At present, we can't tell what route the code is taking, since we don't know what pattern on D, gives '16'...
Correct some obvious errors:
Read the data sheet. Work out why you should not use ADC_CLOCK_INTERNAL.
What is the C command for _testing_equality, rather than setting a value. Are you using this?.
The last one is probably what is causing the problem.....
Best Wishes |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Mon Mar 02, 2009 11:34 am |
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Look at this page about common beginner problems in C:
http://drpaulcarter.com/cs/common-c-errors.php
In CCS, an 'int' is an 8-bit unsigned variable. For a 16-bit unsigned
variable, declare it as 'int16'. |
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Wayne_
Joined: 10 Oct 2007
Posts: 681
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| Posted: Tue Mar 03, 2009 3:12 am |
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You could improve the code no end by storing those bit patterns in an array.
something like
| Code: |
int const num[10] = {
0b00111111, // 0
0b00000110, // 1
0b01001111, // 3
0b01011011, // 2
0b01100110, // 4
0b01101101, // 5
0b01111101, // 6
0b00000111, // 7
0b01111111, // 8
0b01101111}; // 9
portb = num[temp / 10];
portd = num[temp % 10];
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Lcj100
Joined: 29 Nov 2008
Posts: 3
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| Posted: Tue Mar 03, 2009 1:40 pm |
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| Ttelmah wrote: | Start, by telling us how the 7segment is wired. At present, we can't tell what route the code is taking, since we don't know what pattern on D, gives '16'...
Correct some obvious errors:
Read the data sheet. Work out why you should not use ADC_CLOCK_INTERNAL.
What is the C command for _testing_equality, rather than setting a value. Are you using this?.
The last one is probably what is causing the problem.....
Best Wishes |
I'm using two seven segments display. One of the seven segment will be connected to port b0-b6 along with 390 ohm resistor for each port. The other seven segment will be connected to port d0-d6 along with 390 ohm resistor for each port. Both of the seven segments common cathode pin will be grounded. If i want to display 16 in seven segment. The port b pattern will display "1" which is 00000110 means b7b6b5b4b3b2b1b0 while the port d will display "6" which is 01111101 means d7d6d5d4d3d2d1d0. Can i know what do u mean by testing equality in this case? |
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Guest
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| Posted: Tue Mar 03, 2009 2:03 pm |
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oh, good grief  How can you possibly be a "final year student"??
You need to do this:
Instead of this:
Part of being an engineer is NOT expecting to be spoon fed everything....
The CodeWarrior |
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