Merge pull request #7 from hasenbanck/BufferedEEPROM

Add an example for the buffered EEPROM access

Author: fpistm

examples/NonReg/BufferedEEPROM/BufferedEEPROM.ino

@@ -0,0 +1,48 @@
+#include "Arduino.h"
+#include <stdint.h>
+
+/**
+ * Most STM32 devices don't have an integrated EEPROM.
+ * To emulate a EEPROM, the STM32 Arduino core emulated
+ * the operation of an EEPROM with the help of the embedded
+ * flash.
+ *
+ * Writing to a flash is very expensive operation, since a
+ * whole flash page needs to be written, even if you only
+ * want to access the flash byte-wise.
+ *
+ * The STM32 Arduino core provides a buffered access API
+ * to the emulated EEPROM. The library has allocated the
+ * buffer even if you don't use the buffered API, so
+ * it's strongly suggested to use the buffered API anyhow.
+ */
+
+#define DATA_LENGTH E2END
+
+void setup() {
+	Serial.begin(115200);
+}
+
+void loop() {
+	// Fill the EEPROM buffer in memory with data
+	for (uint16_t i = 0; i < DATA_LENGTH; i++) {
+		eeprom_buffered_write_byte(i, i % 256);
+	}
+
+	// Copy the data from the buffer to the flash
+	eeprom_buffer_flush();
+
+	// Clear the buffer for demonstration purpose
+	for (uint16_t i = 0; i < DATA_LENGTH; i++) {
+		eeprom_buffered_write_byte(i, 0);
+	}
+
+	// Print the 254th byte of the current buffer (should be 0)
+	Serial.println(eeprom_buffered_read_byte(254));
+
+	// Copy the data from the flash to the buffer
+	eeprom_buffer_fill();
+
+	// Print the 254th byte of the current buffer (should be 254)
+	Serial.println(eeprom_buffered_read_byte(254));
+}