Analog Devices / tempsensors

Important changes to repositories hosted on mbed.com

Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.

To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.

It is also possible to export all your personal repositories from the account settings page.

Files at this revision

API Documentation at this revision

Revision 4:d8246c20aed2, committed 2021-07-01

Comitter:
mahphalke
Date:
Thu Jul 01 13:41:18 2021 +0530
Parent:
3:a49cef3daae5
Commit message:
Adding equation to calculate 10K 44031 NTC temperature using Beta value

Changed in this revision

ntc_10k_44031.cpp Show annotated file Show diff for this revision Revisions of this file 
diff -r a49cef3daae5 -r d8246c20aed2 ntc_10k_44031.cpp
--- a/ntc_10k_44031.cpp	Tue May 25 15:28:17 2021 +0530
+++ b/ntc_10k_44031.cpp	Thu Jul 01 13:41:18 2021 +0530
@@ -18,6 +18,15 @@
 #include "thermistor.h"
 #include "ntc_10k_44031.h"
 
+/* Convert the temperature using Beta factor specified for 44031 10K NTC */
+//#define	NTC_10K_44031_CONVERT_USING_BETA_VALUE
+
+#if defined(NTC_10K_44031_CONVERT_USING_BETA_VALUE)
+#define NTC_10K_44031_RESISTANCE_AT_25C		10000	// 10K
+#define NTC_10K_44031_ROOM_TEMP_IN_KELVIN	298.15
+#define NTC_10K_44031_BETA_VALUE			3694
+#endif
+
 #ifdef DEFINE_LOOKUP_TABLES
 /* 10K NTC look-up table. Values are resistance in ohm for temperature
  * range from -10 to 80C with +/-1C tolerance.
@@ -61,13 +70,20 @@
 
 /*!
  * @brief	Convert the thermistor resistance into equivalent temperature using
- *			Steinhart-Hart equation for 10K 44031 NTC
+ *			Steinhart-Hart equation Or Beta value for 10K 44031 NTC
  * @param	resistance[in] - thermistor resistance
- * @return	Thermistor temperature value
+ * @return	Thermistor temperature value in Celcius
  */
 float ntc_10k_44031rc::convert(const float resistance)
 {
+#if defined(NTC_10K_44031_CONVERT_USING_BETA_VALUE)
+	float temperature;
+	temperature = (1 / ((log(resistance / NTC_10K_44031_RESISTANCE_AT_25C) /
+			     NTC_10K_44031_BETA_VALUE) + (1 / NTC_10K_44031_ROOM_TEMP_IN_KELVIN))) - 273.15;
+	return temperature;
+#else
 	return thermistor::convert(resistance, coeff_A, coeff_B, coeff_C);
+#endif
 }