added flash array declaration macros

library.properties

 name=Nano33BLE-flash
-version=0.2
+version=0.3
 author=Roger De Roo
 maintainer=Roger De Roo
 sentence=Direct flash memory access 

src/Nano33BLEflash.h

@@ -9,6 +9,44 @@
 
 #ifdef NRF52840_XXAA   // this is defined iff Nano 33 BLE is selected
 
+// the lowest flash address
+#define _NANO33BLE_FLASH_BASE (0x0)
+
+// set static unsigned int _flashAddr to one byte after the top of flash
+#define NANO33BLE_FLASH_INIT() \
+_flashAddr = (_NANO33BLE_FLASH_BASE + NRF_FICR->CODESIZE * NRF_FICR->CODEPAGESIZE);
+
+// private macro:  move _flashAddr down by the size of the array being declared
+// cannot be done directly in NANO33BLE_FLASH macro
+#define _NANO33BLE_FLASH_DECR_ADDR(_bytesInArray) \
+_flashAddr -= (_bytesInArray);
+
+// public macro:  declare array in flash at highest flash addresses available
+// first push _arrayAddr down by size of array in bytes,
+// then use array - pointer equivalence to declare a pointer to that address
+#define NANO33BLE_FLASH( _datatype, _arrayName, _numberOfArrayElements ) \
+_NANO33BLE_FLASH_DECR_ADDR((sizeof(_datatype)) * (_numberOfArrayElements)) \
+_datatype *_arrayName = (_datatype *)_flashAddr;
+
+// public macro to be used after all the flash array declarations
+// useful for looping over flash pages to initialize/erase them.  
+#define NANO33BLE_FLASH_LOWEST_PAGE \
+  ((_flashAddr - _NANO33BLE_FLASH_BASE) / NRF_FICR->CODEPAGESIZE)
+
+// test.  result:  don't do sizeof(#_datatype)
+#define NANO33BLE_FLASH_SIZEOF(_datatype) \
+  (sizeof(_datatype))
+/*
+   // these two defines below do work...
+#define NANO33BLE_FLASH_INT(_arrayName) \
+  int *_arrayName = (int *)0x100000;
+
+#define NANO33BLE_FLASH_DECL(TYPE,_arrayName) \
+  TYPE *_arrayName = (TYPE *)0x100000;
+  */
+
+static unsigned int _flashAddr = (_NANO33BLE_FLASH_BASE + NRF_FICR->CODESIZE * NRF_FICR->CODEPAGESIZE);
+
 // Caution:  these enums are the register settings for the given mode.
 enum _flashModeEnum{
   FLASH_READONLY = NVMC_CONFIG_WEN_Ren << NVMC_CONFIG_WEN_Pos, // 0, 
@@ -16,9 +54,9 @@ enum _flashModeEnum{
   FLASH_ERASE    = NVMC_CONFIG_WEN_Een << NVMC_CONFIG_WEN_Pos  // 2
 };
 
-const int flashBytesPerPage  = NRF_FICR->CODEPAGESIZE;  //  4096 bytes
-const int flashBytesPerWord  = 4;
-const int flashNumberOfPages = NRF_FICR->CODESIZE;      //  256 pages
+const unsigned int flashBytesPerPage  = NRF_FICR->CODEPAGESIZE;  //  4096 bytes
+const unsigned int flashBytesPerWord  = 4;
+const unsigned int flashNumberOfPages = NRF_FICR->CODESIZE;      //  256 pages
 
 void flashMode(_flashModeEnum mode);
 int flashErasePage(byte page);