Merge pull request milesburton#13 from gitkomodo/master

Change timeout when blocking till conversion is complete

Author: RobTillaart

DallasTemperature.cpp

@@ -15,10 +15,10 @@ extern "C" {
 
 // OneWire commands
 #define STARTCONVO 0x44 // Tells device to take a temperature reading and put it on the scratchpad
-#define COPYSCRATCH 0x48 // Copy EEPROM
-#define READSCRATCH 0xBE // Read EEPROM
-#define WRITESCRATCH 0x4E // Write to EEPROM
-#define RECALLSCRATCH 0xB8 // Reload from last known
+#define COPYSCRATCH 0x48 // Copy scratchpad to EEPROM
+#define READSCRATCH 0xBE // Read from scratchpad
+#define WRITESCRATCH 0x4E // Write to scratchpad
+#define RECALLSCRATCH 0xB8 // Recall from EEPROM to scratchpad
 #define READPOWERSUPPLY 0xB4 // Determine if device needs parasite power
 #define ALARMSEARCH 0xEC // Query bus for devices with an alarm condition
 
@@ -41,20 +41,15 @@ extern "C" {
 
 #define NO_ALARM_HANDLER ((AlarmHandler *)0)
 
-DallasTemperature::DallasTemperature()
-{
+DallasTemperature::DallasTemperature() {
 #if REQUIRESALARMS
 setAlarmHandler(NO_ALARM_HANDLER);
 #endif
  useExternalPullup = false;
 }
-DallasTemperature::DallasTemperature(OneWire* _oneWire)
-{
+
+DallasTemperature::DallasTemperature(OneWire* _oneWire) : DallasTemperature() {
 setOneWire(_oneWire);
-#if REQUIRESALARMS
-setAlarmHandler(NO_ALARM_HANDLER);
-#endif
- useExternalPullup = false;
 }
 
 bool DallasTemperature::validFamily(const uint8_t* deviceAddress) {
@@ -74,8 +69,8 @@ bool DallasTemperature::validFamily(const uint8_t* deviceAddress) {
  * Constructs DallasTemperature with strong pull-up turned on. Strong pull-up is mandated in DS18B20 datasheet for parasitic
  * power (2 wires) setup. (https://datasheets.maximintegrated.com/en/ds/DS18B20.pdf, p. 7, section 'Powering the DS18B20').
  */
-DallasTemperature::DallasTemperature(OneWire* _oneWire, uint8_t _pullupPin) : DallasTemperature(_oneWire){
-  setPullupPin(_pullupPin);
+DallasTemperature::DallasTemperature(OneWire* _oneWire, uint8_t _pullupPin) : DallasTemperature(_oneWire) {
+ setPullupPin(_pullupPin);
 }
 
 void DallasTemperature::setPullupPin(uint8_t _pullupPin) {
@@ -267,7 +262,7 @@ void DallasTemperature::setResolution(uint8_t newResolution) {
 }
 
 // set resolution of a device to 9, 10, 11, or 12 bits
-// if new resolution is out of range, 9 bits is used.
+// if new resolution is out of range, it is constrained.
 bool DallasTemperature::setResolution(const uint8_t* deviceAddress,
 uint8_t newResolution, bool skipGlobalBitResolutionCalculation) {
 
@@ -428,16 +423,16 @@ bool DallasTemperature::requestTemperaturesByAddress(
 // Continue to check if the IC has responded with a temperature
 void DallasTemperature::blockTillConversionComplete(uint8_t bitResolution) {
 
-unsigned long delms = millisToWaitForConversion(bitResolution);
-if (checkForConversion && !parasite) {
-unsigned long start = millis();
-while (!isConversionComplete() && (millis() - start < delms))
-yield();
-} else {
-  activateExternalPullup();
-delay(delms);
-  deactivateExternalPullup();
-}
+ if (checkForConversion && !parasite) {
+ unsigned long start = millis();
+ while (!isConversionComplete() && (millis() - start < MAX_CONVERSION_TIMEOUT ))
+ yield();
+ } else {
+ unsigned long delms = millisToWaitForConversion(bitResolution);
+ activateExternalPullup();
+ delay(delms);
+ deactivateExternalPullup();
+ }
 
 }
 
@@ -480,11 +475,10 @@ bool DallasTemperature::requestTemperaturesByIndex(uint8_t deviceIndex) {
 // Fetch temperature for device index
 float DallasTemperature::getTempCByIndex(uint8_t deviceIndex) {
 
-DeviceAddress deviceAddress;
+DeviceAddress deviceAddress;
 if (!getAddress(deviceAddress, deviceIndex)) {
 return DEVICE_DISCONNECTED_C;
 }
-
 return getTempC((uint8_t*) deviceAddress);
 
 }

DallasTemperature.h

@@ -37,6 +37,9 @@
 #define DEVICE_DISCONNECTED_F -196.6
 #define DEVICE_DISCONNECTED_RAW -7040
 
+// Other
+#define MAX_CONVERSION_TIMEOUT 750
+
 // For readPowerSupply on oneWire bus
 #ifndef nullptr
 #define nullptr NULL