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Message |
cxiong
Joined: 09 Sep 2003
Posts: 52
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| printf a floating # |
 Posted: Thu Sep 02, 2004 2:56 pm |
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I have the PIC Demo 2 Plus and I write the code to measure a ADC channel as voltage and display it on the LCD as floating. I only want to print 2 #s after the decimal point only. I know that in C, if you print 2 #s after the decimal point is to put a . between the % and f. But it does not work for CCS. Its there anything I missing?
Here is my code:
| Code: |
/////////////////////////////////////////////////////////////////////////
//// EX_TC74.C ////
//// I2C serial concept ////
//// This program uses the TC74 TO-220-5 to ////
//// read the temperature for the sensor. ////
//// ////
//// TC74 pin Processor ////
//// 1 n/a NC ////
//// 2 23 RC3 SDA ////
//// 3 n/a gnd ////
//// 4 18 RC3 SCL ////
//// 5 n/a VDD ////
//// ////
/////////////////////////////////////////////////////////////////////////
#include <18f458.h>
#device ADC=10
#fuses XT,NOWDT,NOPROTECT,NOLVP
#use delay(clock=4000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)
#use i2c(Master,fast,sda=PIN_C4, scl=PIN_C3, FORCE_HW)
#include <lcdd.c>
main()
{
byte value,temp;
int16 bat_value;
float batt;
lcd_init();
setup_adc_ports( RA0_ANALOG );
setup_adc( ADC_CLOCK_INTERNAL );
while(1)
{
set_adc_channel( 0 );
delay_us(25);
bat_value = read_adc();
batt = bat_value * (float) 0.00488;
printf(lcd_putc,"\nBattery: %.2f V",batt);
delay_ms(100);
i2c_Start(); // Set a START condition I2C Bus
i2c_Write(0b10011010); // Address and Write Flag
i2c_Write(0x00); // Temperature Register
i2c_Start(); // Set a START condition I2C Bus
i2c_Write(0b10011011); // Address and Read Flag
value = i2c_Read(); // Read Teperature
i2c_stop();
delay_ms(5);
temp = value * 9/5 + 32;
printf("Temp: %d Degree\n\r",temp);
printf(lcd_putc,"\fValue: %d Degree",temp);
if(value < 21)
{
output_high(PIN_B0);
output_low(PIN_B0);
}
else
{
output_high(PIN_B1);
output_low(PIN_B0);
}
}
}
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The error message ( printf format % is invalid).
Please help. |
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dyeatman
Joined: 06 Sep 2003
Posts: 1933
Location: Norman, OK
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| Like Prego, its in there... |
| Posted: Thu Sep 02, 2004 3:15 pm |
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Doesn't ANYONE read the manual any more??
Taken from page 125 for Printf():
The format takes the generic form %wt where w is optional and may be 1-9 to specify how many characters are to be outputted, or 01-09 to indicate leading zeros or 1.1 to 9.9 for floating point. t is the type and may be one of the following:
C Character
S String or character
U Unsigned int
etc... |
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cxiong
Joined: 09 Sep 2003
Posts: 52
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| Posted: Fri Sep 03, 2004 7:25 am |
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I just download the manual from CCS. It does cover the topic I ask for.
Thanks. |
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SherpaDoug
Joined: 07 Sep 2003
Posts: 1640
Location: Cape Cod Mass USA
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| Posted: Fri Sep 03, 2004 7:58 am |
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The CCS manual is fairly small and if you are going to do any serious work it is worth reading cover to cover. You will discover lots of things you never thought to ask for!
_________________
The search for better is endless. Instead simply find very good and get the job done. |
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