Fix #158: add API to get configured clock rate

src/CatenaBase.h

@@ -91,7 +91,7 @@ Revision history:
 #define CATENA_ARDUINO_PLATFORM_VERSION_CALC(major, minor, patch, local)	\
 	(((major) << 24u) | ((minor) << 16u) | ((patch) << 8u) | (local))
 
-#define	CATENA_ARDUINO_PLATFORM_VERSION	CATENA_ARDUINO_PLATFORM_VERSION_CALC(0, 14, 0, 61)	/* v0.14.0.61 */
+#define	CATENA_ARDUINO_PLATFORM_VERSION	CATENA_ARDUINO_PLATFORM_VERSION_CALC(0, 14, 0, 62)	/* v0.14.0.62 */
 
 #define	CATENA_ARDUINO_PLATFORM_VERSION_GET_MAJOR(v)	\
 	(((v) >> 24u) & 0xFFu)
@@ -264,6 +264,10 @@ class CatenaBase
 
 	inline uint32_t GetPlatformFlags(void);
 
+	// get system clock rate in Hz; must be overridden
+	virtual uint64_t GetSystemClockRate(void) const = 0;
+
+	// start the Catena framework.
         virtual bool begin(void);
 
 	virtual const char *CatenaName(void) const = 0; // requires that an override be provided.

src/CatenaFeatherM0.h

@@ -81,6 +81,12 @@ class CatenaFeatherM0 : public CatenaSamd21
 		PIN_STATUS_LED = 13,
 		};
 
+	// get system clock rate in Hz. Always fixed for Feathers.
+	virtual uint64_t GetSystemClockRate(void) const override
+		{
+		return 48 * 1000 * 1000;
+		}
+
 	// methods
 	virtual bool begin() override;
 

src/CatenaStm32L0.h

@@ -93,6 +93,9 @@ class CatenaStm32L0 : public CatenaStm32
 			uint32_t Multiplier = 1
 			) const;
 
+	// get system clock rate in Hz; must be overridden
+	virtual uint64_t GetSystemClockRate(void) const override;
+
 	// read the current battery voltage, in engineering units
 	virtual float ReadVbat(void) const = 0;
 	virtual float ReadVbus(void) const = 0;

src/lib/stm32/stm32l0/CatenaStm32L0_GetSystemClockRate.cpp

@@ -0,0 +1,90 @@
+/*
+
+Module:  CatenaStm32L0_GetSystemClockRate.cpp
+
+Function:
+	CatenaStm32L0::GetSystemClockRate()
+
+Copyright notice:
+	See accompanying license
+
+Author:
+	Terry Moore, MCCI Corporation	April 2019
+
+*/
+
+#ifdef ARDUINO_ARCH_STM32
+
+#include "CatenaStm32L0.h"
+
+#include <Arduino.h>
+
+using namespace McciCatena;
+
+/****************************************************************************\
+|
+|	Manifest constants & typedefs.
+|
+\****************************************************************************/
+
+
+/****************************************************************************\
+|
+|	Read-only data.
+|
+\****************************************************************************/
+
+
+
+/****************************************************************************\
+|
+|	Variables.
+|
+\****************************************************************************/
+
+
+/*
+
+Name:	CatenaStm32L0::GetSystemCLockRate
+
+Function:
+	Return the system clock rate
+
+Definition:
+	virtual uint64_t CatenaStm32L0::GetSystemClockRate(
+		void
+		) const override;
+
+Description:
+	The clock rate returned is the value set at compile time
+	by CATENA_CFG_SYSCLK. The value we return is the correct
+	nominal value, in Hz.
+
+Returns:
+	Analog value
+
+*/
+
+uint64_t CatenaStm32L0::GetSystemClockRate(
+	void
+	) const
+	{
+	switch (CATENA_CFG_SYSCLK)
+		{
+	case 2:
+		return 2097 * 1000;
+	case 4:
+		return 4194 * 1000;
+	case 16:
+		return 16 * 1000 * 1000;
+	case 24:
+		return 24 * 1000 * 1000;
+	default:
+	case 32:
+		return 32 * 1000 * 1000;
+		}
+	}
+
+#endif // ARDUINO_ARCH_STM32
+
+/**** end of CatenaStm32L0_GetSystemClockRate.cpp ****/