sshahryiar
Joined: 05 May 2010
Posts: 94
Location: Dhaka, Bangladesh
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| HSM-20S Relative Humidity Temperature Sensor Demo |
 Posted: Sun Nov 23, 2014 10:10 am |
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| Code: |
#include <16F877A.h>
#device *= 16
#device ADC = 10
#fuses NOWDT, PROTECT, CPD, NOLVP, HS
#fuses NOBROWNOUT, NODEBUG, NOWRT, PUT
#use delay (clock = 10MHz)
#include "lcd.c"
const unsigned char symbol[8] = {0x00 ,0x0E, 0x0A ,0x0E, 0x00, 0x00, 0x00, 0x00};
void setup();
void lcd_symbols();
void get_parameters(float *relative_humidity, float *temperature);
void main()
{
float t = 0;
float rh = 0;
setup();
while(TRUE)
{
get_parameters(&rh, &t);
lcd_gotoxy(9, 1);
printf(lcd_putc, "%3.2g ", rh);
lcd_gotoxy(9, 2);
printf(lcd_putc, "%3.2g ", t);
};
}
void setup()
{
disable_interrupts(global);
setup_timer_0(T0_internal);
setup_timer_1(T1_disabled);
setup_timer_2(T2_disabled, 255, 1);
set_timer0(0);
set_timer1(0);
set_timer2(0);
setup_CCP1(CCP_off);
setup_CCP2(CCP_off);
setup_psp(PSP_disabled);
setup_comparator(NC_NC_NC_NC);
setup_SPI(SPI_disabled);
port_B_pullups(FALSE);
setup_ADC(ADC_clock_internal);
set_analog_pins(AN0_AN1_AN3);
lcd_init();
lcd_symbols();
lcd_putc("\f");
lcd_gotoxy(3, 1);
lcd_putc("RH/%:");
lcd_gotoxy(3, 2);
lcd_putc("T/ C:");
lcd_gotoxy(5, 2);
lcd_putc(0);
}
void lcd_symbols()
{
unsigned char s = 0;
lcd_send_byte(0, 0x40);
for(s = 0; s < 8; s++)
{
lcd_send_byte(1, symbol[s]);
}
lcd_send_byte(0, 0x80);
}
void get_parameters(float *relative_humidity, float *temperature)
{
unsigned long samples = 256;
register unsigned long long avg_rh = 0;
register unsigned long long avg_t = 0;
while(samples > 0)
{
set_ADC_channel(0);
delay_ms(1);
read_adc(adc_start_only);
while(adc_done() == 0);
avg_rh += read_adc(adc_read_only);
set_ADC_channel(1);
delay_ms(1);
read_adc(adc_start_only);
while(adc_done() == 0);
avg_t += read_adc(adc_read_only);
samples--;
};
avg_rh >>= 8;
avg_t >>= 8;
*relative_humidity = ((0.1507 * avg_rh) - 11.4378);
*temperature = ((-0.0002 * avg_t * avg_t) + (avg_t * 0.2268) - 11.4945);
}
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SShahryiar |
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