Fixed hang due to consecutive read tempurature

fix the hang issue due to consecutive reads of the temperature register

porting of arduino-libraries/Arduino_MKRENV#6

Author: Rocketct

src/HTS.cpp

@@ -57,7 +57,7 @@ int HTS221Class::begin()
   readHTS221Calibration();
 
   // enable HTS221
-  i2cWrite(HTS221_CTRL1_REG, 0x80);
+  i2cWrite(HTS221_CTRL1_REG, 0x84);
 
   return 1;
 }
@@ -72,6 +72,9 @@ void HTS221Class::end()
 
 float HTS221Class::readTemperature(int units)
 {
+  // Wait for trigger a new read operation
+  while (HTS221_CTRL2_REG) & 0x01);
+
   // trigger one shot
   i2cWrite(HTS221_CTRL2_REG, 0x01);
 
@@ -92,6 +95,9 @@ float HTS221Class::readTemperature(int units)
 
 float HTS221Class::readHumidity()
 {
+  // Wait for trigger a new read operation
+  while (HTS221_CTRL2_REG) & 0x01);
+
   // trigger one shot
   i2cWrite(HTS221_CTRL2_REG, 0x01);
 
@@ -102,8 +108,8 @@ float HTS221Class::readHumidity()
 
   // read value and convert
   int16_t hout = i2cRead16(HTS221_HUMIDITY_OUT_L_REG);
-
-  return (hout * _hts221HumiditySlope + _hts221HumidityZero);
+  float reading = hout * _hts221HumiditySlope + _hts221HumidityZero;
+  return reading;
 }
 
 int HTS221Class::i2cRead(uint8_t reg)