From 0370bec69d8a5051f14fbac1ec71daae5bd57231 Mon Sep 17 00:00:00 2001
From: Felix Rusu <felix@lowpowerlab.com>
Date: Thu, 29 May 2014 14:32:12 -0400
Subject: [PATCH] Add readUniqueId() to get unique 64 bit MAC

Reads 64 bit MAC unique ID
---
 SPIFlash.cpp | 21 +++++++++++++++++++++
 SPIFlash.h   |  6 +++++-
 keywords.txt |  2 ++
 3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/SPIFlash.cpp b/SPIFlash.cpp
index 906a795..a0538da 100644
--- a/SPIFlash.cpp
+++ b/SPIFlash.cpp
@@ -14,6 +14,8 @@
 
 #include <SPIFlash.h>
 
+byte SPIFlash::UNIQUEID[8];
+
 /// IMPORTANT: NAND FLASH memory requires erase before write, because
 ///            it can only transition from 1s to 0s and only the erase command can reset all 0s to 1s
 /// See http://en.wikipedia.org/wiki/Flash_memory
@@ -74,6 +76,25 @@ word SPIFlash::readDeviceId()
   return jedecid;
 }
 
+/// Get the 64 bit unique identifier, stores it in UNIQUEID[8]. Only needs to be called once, ie after initialize
+/// Returns the byte pointer to the UNIQUEID byte array
+/// Read UNIQUEID like this:
+/// flash.readUniqueId(); for (byte i=0;i<8;i++) { Serial.print(flash.UNIQUEID[i], HEX); Serial.print(' '); }
+/// or like this:
+/// flash.readUniqueId(); byte* MAC = flash.readUniqueId(); for (byte i=0;i<8;i++) { Serial.print(MAC[i], HEX); Serial.print(' '); }
+byte* SPIFlash::readUniqueId()
+{
+  command(SPIFLASH_MACREAD);
+  SPI.transfer(0);
+  SPI.transfer(0);
+  SPI.transfer(0);
+  SPI.transfer(0);
+  for (byte i=0;i<8;i++)
+    UNIQUEID[i] = SPI.transfer(0);
+  unselect();
+  return UNIQUEID;
+}
+
 /// read 1 byte from flash memory
 byte SPIFlash::readByte(long addr) {
   command(SPIFLASH_ARRAYREADLOWFREQ);
diff --git a/SPIFlash.h b/SPIFlash.h
index 5432ce3..be049d4 100644
--- a/SPIFlash.h
+++ b/SPIFlash.h
@@ -65,9 +65,11 @@
 #define SPIFLASH_IDREAD           0x9F        // read JEDEC manufacturer and device ID (2 bytes, specific bytes for each manufacturer and device)
                                               // Example for Atmel-Adesto 4Mbit AT25DF041A: 0x1F44 (page 27: http://www.adestotech.com/sites/default/files/datasheets/doc3668.pdf)
                                               // Example for Winbond 4Mbit W25X40CL: 0xEF30 (page 14: http://www.winbond.com/NR/rdonlyres/6E25084C-0BFE-4B25-903D-AE10221A0929/0/W25X40CL.pdf)
-
+#define SPIFLASH_MACREAD          0x4B        // read unique ID number (MAC)
+                                              
 class SPIFlash {
 public:
+  static byte UNIQUEID[8];
   SPIFlash(byte slaveSelectPin, uint16_t jedecID=0);
   boolean initialize();
   void command(byte cmd, boolean isWrite=false);
@@ -81,6 +83,8 @@ public:
   void blockErase4K(long address);
   void blockErase32K(long address);
   word readDeviceId();
+  byte* readUniqueId();
+  
   void sleep();
   void wakeup();
   void end();
diff --git a/keywords.txt b/keywords.txt
index 6c6903c..652da98 100644
--- a/keywords.txt
+++ b/keywords.txt
@@ -11,6 +11,8 @@ chipErase	KEYWORD2
 blockErase4K	KEYWORD2
 blockErase32K	KEYWORD2
 readDeviceId	KEYWORD2
+readUniqueId	KEYWORD2
+UNIQUEID	KEYWORD2
 sleep	KEYWORD2
 wakeup	KEYWORD2
 end	KEYWORD2
\ No newline at end of file