initial upload

examples/osd/arduino-climate3/Adafruit_HTU21DF_Library-master/Adafruit_HTU21DF.cpp

@@ -0,0 +1,100 @@
+/*************************************************** 
+  This is a library for the HTU21DF Humidity & Temp Sensor
+
+  Designed specifically to work with the HTU21DF sensor from Adafruit
+  ----> https://www.adafruit.com/products/1899
+
+  These displays use I2C to communicate, 2 pins are required to  
+  interface
+  Adafruit invests time and resources providing this open source code, 
+  please support Adafruit and open-source hardware by purchasing 
+  products from Adafruit!
+
+  Written by Limor Fried/Ladyada for Adafruit Industries.  
+  BSD license, all text above must be included in any redistribution
+ ****************************************************/
+
+#include "Adafruit_HTU21DF.h"
+#if defined(__AVR__)
+#include <util/delay.h>
+#endif
+
+Adafruit_HTU21DF::Adafruit_HTU21DF() {
+}
+
+
+boolean Adafruit_HTU21DF::begin(void) {
+  Wire.begin();
+  
+  reset();
+
+  Wire.beginTransmission(HTU21DF_I2CADDR);
+  Wire.write(HTU21DF_READREG);
+  Wire.endTransmission();
+  Wire.requestFrom(HTU21DF_I2CADDR, 1);
+  return (Wire.read() == 0x2); // after reset should be 0x2
+}
+
+void Adafruit_HTU21DF::reset(void) {
+  Wire.beginTransmission(HTU21DF_I2CADDR);
+  Wire.write(HTU21DF_RESET);
+  Wire.endTransmission();
+  delay(15);
+}
+
+
+float Adafruit_HTU21DF::readTemperature(void) {
+  
+  // OK lets ready!
+  Wire.beginTransmission(HTU21DF_I2CADDR);
+  Wire.write(HTU21DF_READTEMP);
+  Wire.endTransmission();
+  
+  delay(50); // add delay between request and actual read!
+  
+  Wire.requestFrom(HTU21DF_I2CADDR, 3);
+  while (!Wire.available()) {}
+
+  uint16_t t = Wire.read();
+  t <<= 8;
+  t |= Wire.read();
+
+  uint8_t crc = Wire.read();
+
+  float temp = t;
+  temp *= 175.72;
+  temp /= 65536;
+  temp -= 46.85;
+
+  return temp;
+}
+  
+
+float Adafruit_HTU21DF::readHumidity(void) {
+  // OK lets ready!
+  Wire.beginTransmission(HTU21DF_I2CADDR);
+  Wire.write(HTU21DF_READHUM);
+  Wire.endTransmission();
+  
+  delay(50); // add delay between request and actual read!
+  
+  Wire.requestFrom(HTU21DF_I2CADDR, 3);
+  while (!Wire.available()) {}
+
+  uint16_t h = Wire.read();
+  h <<= 8;
+  h |= Wire.read();
+
+  uint8_t crc = Wire.read();
+
+  float hum = h;
+  hum *= 125;
+  hum /= 65536;
+  hum -= 6;
+
+  return hum;
+}
+
+
+
+/*********************************************************************/