1,103 → 1,13 |
/* |
SHT25 sensor demo firmware |
*/ |
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#include "main.h" |
#include "SHT25.h" |
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void SHT25_soft_reset() |
{ |
i2c_start(); // Start condition |
i2c_write(0x80); // Device address |
i2c_write(0xFE); // Device command |
i2c_stop(); // Stop condition |
} |
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#define SHT25_HEATER_ON 0x04 |
#define SHT25_HEATER_OFF 0x00 |
#define SHT25_OTP_reload_off 0x02 |
#define SHT25_RH12_T14 0x00 |
#define SHT25_RH8_T12 0x01 |
#define SHT25_RH10_T13 0x80 |
#define SHT25_RH11_T11 0x81 |
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#define SHT25_ADDR 0x80 |
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unsigned int8 SHT25_setup(unsigned int8 setup_reg ) // writes to status register and returns its value |
{ |
unsigned int8 reg; |
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i2c_start(); // Start condition |
i2c_write(SHT25_ADDR); // Device address |
i2c_write(0xE7); // Device command |
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i2c_start(); // Start condition |
i2c_write(SHT25_ADDR+1); // Device address |
reg=i2c_read(0); // Read status actual status register |
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reg = (reg & 0x3A) | setup_reg; |
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i2c_start(); // Start condition |
i2c_write(SHT25_ADDR); // Device address |
i2c_write(0xE7); // Write to status register |
i2c_write(reg); // Device command |
i2c_stop(); // Stop condition |
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return (reg); |
} |
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float SHT25_get_temp() |
{ |
unsigned int8 MSB, LSB, Check; |
unsigned int16 data; |
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i2c_start(); |
I2C_Write(SHT25_ADDR); |
I2C_write(0xE3); |
i2c_stop(); |
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delay_ms(100); |
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i2c_start(); |
I2C_Write(SHT25_ADDR+1); |
MSB=i2c_read(1); |
LSB=i2c_read(1); |
Check=i2c_read(0); |
i2c_stop(); |
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LSB = LSB >> 2; // trow out status bits |
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data = (((unsigned int16) MSB << 8) + (LSB << 4)); |
return(-46.85 + 175.72*((float)data/0xFFFF)); |
} |
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float SHT25_get_hum() |
{ |
unsigned int8 MSB, LSB, Check; |
unsigned int16 data; |
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i2c_start(); //RH |
I2C_Write(SHT25_ADDR); |
I2C_write(0xE5); |
// i2c_stop(); |
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delay_ms(100); |
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i2c_start(); |
I2C_Write(SHT25_ADDR+1); |
MSB=i2c_read(1); |
LSB=i2c_read(1); |
Check=i2c_read(0); |
i2c_stop(); |
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// printf("%X %X %X\r\n",MSB, LSB, Check); |
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LSB = LSB >> 2; // trow out status bits |
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data = (((unsigned int16) MSB << 8) + (LSB << 4) ); |
return( -6.0 + 125.0*((float)data/0xFFFF)); |
} |
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void main() |
{ |
unsigned int8 i=0; |
unsigned int8 i=0, sht_config; |
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setup_adc_ports(NO_ANALOGS|VSS_VDD); |
setup_adc(ADC_CLOCK_DIV_2); |
114,13 → 24,13 |
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while(TRUE) |
{ |
if (i<10) |
printf("setup: %X \r\n",SHT25_setup(SHT25_RH12_T14 | SHT25_HEATER_OFF)); |
if (i<10) sht_config = SHT25_RH12_T14 | SHT25_HEATER_OFF; // loop alters on chip heater on and off to check correct function |
else |
{ |
printf("setup: %X \r\n",SHT25_setup(SHT25_RH12_T14 | SHT25_HEATER_ON)); |
i = 0; |
sht_config = SHT25_RH12_T14 | SHT25_HEATER_ON; |
if (i > 20) i = 0; |
} |
printf("setup: %X %X \r\n",SHT25_setup(sht_config),sht_config); |
delay_ms (500); |
printf("Temp: %f \r\n",SHT25_get_temp()); |
delay_ms (500); |