Svenska ElektronikForumet

Kod: Markera allt

/*
* Read HH10D humidity sensor (http://www.sparkfun.com/products/10239)
* It contains a M24C02BN6 Eeprom with calibration values.
* 
* Author: Patrik Hermansson, www.patrikhermansson.se
* Date: 110309
*
* Example calibration values:                          
* Sensitivity: 327
* Offset: 7499
*
* Connections:
* Vss - Gnd
* Vdd - +3.3V
* Fout - D5 (Mega168 pin 11)
* SDA - A4 (pin 27)
* SCL - A5 (pin 28)
*/ 
                  
#include <Wire.h>
#include <FreqCounter.h>	// http://interface.khm.de/index.php/lab/experiments/arduino-frequency-counter-library/

int rv = 0, offset;
float sens;
long int freq;


void setup() {
	Wire.begin();
	Serial.begin(38400);
	Serial.println("Hi!");

	readCalib(81,10);
        sens = rv;
        // Debug, test without I2C connection
        //sens = 327;
	Serial.print("Sensitivity: ");
	Serial.println(sens);
 
	readCalib(81,12);
        offset=rv;
        // Debug, test without I2C connection
        //offset = 7499;	
        Serial.print("Offset: ");
	Serial.println(offset);	
        
	delay(1000);
}

void loop() {
	// Calculate frequency out from HH10D
	FreqCounter::f_comp= 8;             // Set compensation to 12
	FreqCounter::start(1000);            // Start counting with gatetime of 1000ms
	while (FreqCounter::f_ready == 0)         // wait until counter ready 
		freq=FreqCounter::f_freq;            // read result
	
        float RH = (offset-freq)*(sens/4096);
	//int RH = (7499 - freq) * 0.09033203125;
	Serial.print("Sens: ");
	Serial.println(sens);
	Serial.print("offset: ");
	Serial.println(offset);
	Serial.print("Humidity: ");
	Serial.println(RH);	
	Serial.print("Freq: ");
	Serial.println(freq);	
	Serial.print("offset-freq: ");
	Serial.println(offset-freq);	
	Serial.print("sens/4096: ");
	Serial.println(sens/4096);
	Serial.print("offset-freq)*sens/4096: ");
	Serial.println((offset-freq)*sens/4096);

        delay(10000);
}


int readCalib( int deviceaddress, int calibAddress )   // deviceaddress is 1  according to datasheet
{
    // Set address
    Wire.beginTransmission(deviceaddress);
    Wire.write(calibAddress); 
    Wire.endTransmission();

    // Request return value
    Wire.requestFrom(deviceaddress, 2);
    // Collect return value
    for (int c = 0; c < 2; c++ )
      if (Wire.available()) rv = rv * 256 + Wire.read();
    return rv;
  }