Initial import

code/lib/EEPROM-1.8.19/examples/eeprom_crc/eeprom_crc.ino

@@ -0,0 +1,52 @@
+/***
+    Written by Christopher Andrews.
+    CRC algorithm generated by pycrc, MIT licence ( https://github.com/tpircher/pycrc ).
+
+	A CRC is a simple way of checking whether data has changed or become corrupted.
+	This example calculates a CRC value directly on the EEPROM values.
+	The purpose of this example is to highlight how the EEPROM object can be used just like an array.
+***/
+
+#include <Arduino.h>
+#include <EEPROM.h>
+
+void setup() {
+
+  //Start serial
+  Serial.begin(9600);
+  while (!Serial) {
+    ; // wait for serial port to connect. Needed for native USB port only
+  }
+
+  //Print length of data to run CRC on.
+  Serial.print("EEPROM length: ");
+  Serial.println(EEPROM.length());
+
+  //Print the result of calling eeprom_crc()
+  Serial.print("CRC32 of EEPROM data: 0x");
+  Serial.println(eeprom_crc(), HEX);
+  Serial.print("\n\nDone!");
+}
+
+void loop() {
+  /* Empty loop */
+}
+
+unsigned long eeprom_crc(void) {
+
+  const unsigned long crc_table[16] = {
+    0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
+    0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
+    0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
+    0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
+  };
+
+  unsigned long crc = ~0L;
+
+  for (int index = 0 ; index < EEPROM.length()  ; ++index) {
+    crc = crc_table[(crc ^ EEPROM[index]) & 0x0f] ^ (crc >> 4);
+    crc = crc_table[(crc ^ (EEPROM[index] >> 4)) & 0x0f] ^ (crc >> 4);
+    crc = ~crc;
+  }
+  return crc;
+}