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andys
Joined: 23 Oct 2006
Posts: 175
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| sht71 code problem |
 Posted: Thu Oct 11, 2012 6:21 am |
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I tried to connect sht75 sensor with pic but i get a strange error.
(I use the driver for sht75 which i found from the web) and the dspic30f2010.
The error which I receive is :
*** Error 128 "sht75.c" Line 7(1,13): A #DEVICE required before this line
Is anyone who know how to fix it ?
The code which I use is:
| Code: |
#include <30F2010.h>
//#fuses HS,NOWDT,PUT,NOPROTECT,NOLVP
#fuses HS,NOWDT,NOPROTECT
#use delay(clock=20000000)
#include<lcd.c>
#include<sht75.c>
void main()
{
float restemp, truehumid;
lcd_init();
sht_init();
while(1)
{
sht_rd (restemp, truehumid);
lcd_gotoxy(1,1);
printf(lcd_putc, "Temp : %3.1f %cC ", restemp, 223);
printf(lcd_putc, "\nRH : %3.1f %% ", truehumid);
delay_ms(500); //delay 500 ms between reading to prevent self heating of sensor
}
}
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and the sensor driver:
| Code: |
#define sht_data_pin PIN_C13
#define sht_clk_pin PIN_C14
//***** Function to alert SHT75 *****
void comstart (void)
{
output_float(sht_data_pin); //data high
output_bit(sht_clk_pin, 0); //clk low
delay_us(1);
output_bit(sht_clk_pin, 1); //clk high
delay_us(1);
output_bit(sht_data_pin, 0); //data low
delay_us(1);
output_bit(sht_clk_pin, 0); //clk low
delay_us(2);
output_bit(sht_clk_pin, 1); //clk high
delay_us(1);
output_float(sht_data_pin); //data high
delay_us(1);
output_bit(sht_clk_pin, 0); //clk low
}
//***** Function to write data to SHT75 *****
int1 comwrite (int8 iobyte)
{
int8 i, mask = 0x80;
int1 ack;
//Shift out command
delay_us(4);
for(i=0; i<8; i++)
{
output_bit(sht_clk_pin, 0); //clk low
if((iobyte & mask) > 0) output_float(sht_data_pin); //data high if MSB high
else output_bit(sht_data_pin, 0); //data low if MSB low
delay_us(1);
output_bit(sht_clk_pin, 1); //clk high
delay_us(1);
mask = mask >> 1; //shift to next bit
}
//Shift in ack
output_bit(sht_clk_pin, 0); //clk low
delay_us(1);
ack = input(sht_data_pin); //get ack bit
output_bit(sht_clk_pin, 1); //clk high
delay_us(1);
output_bit(sht_clk_pin, 0); //clk low
return(ack);
}
//***** Function to read data from SHT75 *****
int16 comread (void)
{
int8 i;
int16 iobyte = 0;
const int16 mask0 = 0x0000;
const int16 mask1 = 0x0001;
//shift in MSB data
for(i=0; i<8; i++)
{
iobyte = iobyte << 1;
output_bit(sht_clk_pin, 1); //clk high
delay_us(1);
if (input(sht_data_pin)) iobyte |= mask1; //shift in data bit
else iobyte |= mask0;
output_bit(sht_clk_pin, 0); //clk low
delay_us(1);
}
//send ack 0 bit
output_bit(sht_data_pin, 0); //data low
delay_us(1);
output_bit(sht_clk_pin, 1); //clk high
delay_us(2);
output_bit(sht_clk_pin, 0); //clk low
delay_us(1);
output_float(sht_data_pin); //data high
//shift in LSB data
for(i=0; i<8; i++)
{
iobyte = iobyte << 1;
output_bit(sht_clk_pin, 1); //clk high
delay_us(1);
if (input(sht_data_pin)) iobyte |= mask1; //shift in data bit
else iobyte |= mask0;
output_bit(sht_clk_pin, 0); //clk low
delay_us(1);
}
//send ack 1 bit
output_float(sht_data_pin); //data high
delay_us(1);
output_bit(sht_clk_pin, 1); //clk high
delay_us(2);
output_bit(sht_clk_pin, 0); //clk low
return(iobyte);
}
//***** Function to wait for SHT75 reading *****
void comwait (void)
{
int16 sht_delay;
output_float(sht_data_pin); //data high
output_bit(sht_clk_pin, 0); //clk low
delay_us(1);
for(sht_delay=0; sht_delay<30000; sht_delay++) // wait for max 300ms
{
if (!input(sht_data_pin)) break; //if sht_data_pin low, SHT75 ready
delay_us(10);
}
}
//***** Function to reset SHT75 communication *****
void comreset (void)
{
int8 i;
output_float(sht_data_pin); //data high
output_bit(sht_clk_pin, 0); //clk low
delay_us(2);
for(i=0; i<9; i++)
{
output_bit(sht_clk_pin, 1); //toggle clk 9 times
delay_us(2);
output_bit(sht_clk_pin, 0);
delay_us(2);
}
comstart();
}
//***** Function to soft reset SHT75 *****
void sht_soft_reset (void)
{
comreset(); //SHT75 communication reset
comwrite(0x1e); //send SHT75 reset command
delay_ms(15); //pause 15 ms
}
//***** Function to measure SHT75 temperature *****
//int16 measuretemp (void)
int16 measuretemp ()
{
int1 ack;
int16 iobyte;
comstart(); //alert SHT75
ack = comwrite(0x03); //send measure temp command and read ack status
if(ack == 1) return;
comwait(); //wait for SHT75 measurement to complete
iobyte = comread(); //read SHT75 temp data
return(iobyte);
}
//***** Function to measure SHT75 RH *****
int16 measurehumid ()
//int16 measurehumid (void)
{
int1 ack;
int16 iobyte;
comstart(); //alert SHT75
ack = comwrite(0x05); //send measure RH command and read ack status
if(ack == 1) return;
comwait(); //wait for SHT75 measurement to complete
iobyte = comread(); //read SHT75 temp data
return(iobyte);
}
//***** Function to calculate SHT75 temp & RH *****
void calculate_data (int16 temp, int16 humid, float & tc, float & rhlin, float & rhtrue)
{
float truehumid1, rh;
//calculate temperature reading
tc = ((float) temp * 0.01) - 40.0;
//calculate Real RH reading
rh = (float) humid;
rhlin = (rh * 0.0405) - (rh * rh * 0.0000028) - 4.0;
//calculate True RH reading
rhtrue = ((tc - 25.0) * (0.01 + (0.00008 * rh))) + rhlin;
}
//***** Function to measure & calculate SHT75 temp & RH *****
void sht_rd (float & temp, float & truehumid)
{
int16 restemp, reshumid;
float realhumid;
restemp = 0; truehumid = 0;
restemp = measuretemp(); //measure temp
reshumid = measurehumid(); //measure RH
calculate_data (restemp, reshumid, temp, realhumid, truehumid); //calculate temp & RH
}
//***** Function to initialise SHT75 on power-up *****
void sht_init (void)
{
comreset(); //reset SHT75
delay_ms(20); //delay for power-up
}
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andys
Joined: 23 Oct 2006
Posts: 175
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| sht71 code problem |
| Posted: Thu Oct 11, 2012 2:23 pm |
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| No respond yet? |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19515
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| Posted: Fri Oct 12, 2012 12:50 am |
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Are you compiling from CCS, or using MPLAB as a front end?.
If the latter, then it is the old MPLAB problem, that you _must not_ put include files into the 'source files' section of the project. They must be put into the 'header files' section. Otherwise MPLAB tries to compile the files, and (for instance) your sht75 file, won't compile on it's own.
Best Wishes |
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andys
Joined: 23 Oct 2006
Posts: 175
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| sht71 code problem |
| Posted: Fri Oct 12, 2012 5:00 am |
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I used the MPLAB v.8.85.
This is not a new version ? |
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ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
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| Posted: Fri Oct 12, 2012 6:00 am |
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| Ttelmah wrote: | | it is the old MPLAB problem |
| andys wrote: | I used the MPLAB v.8.85.
This is not a new version ? |
It is not a problem about MPLAB being old, but it is a problem that we know is there for a long time. So, 'old problem' as in 'has always been there'.
There is also MPLAB 8.87, but 8.85 is fine.
The problem is not in your version of MPLAB, but in how MPLAB works.
In MPLAB there is a 'Project' screen, open this through menu View/Project.
In this Project screen there is a section called 'Source Files'.
Now, MPLAB will try to compile all *.c files in this list and that is where the CCS compiler fails. Only the file main.c should be in this list, remove all other *.c files like your sht75.c
Good luck. |
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