All functions have been tested and found to work well on Arduino 1.6.x. Please report any issues and I will do my best to fix them. Change log v2.1.1 Fixed bugs that prevented the following functions from working properly powerDown() powerUp() suspendProg() resumeProg() v 2.1.0 Arduino Due compatible - refer to wiki for further details Fixed bug with write/readByteArray Added write/readCharArray Added a proper error checking function that gets called when #ifdef RUNDIAGNOSTIC is uncommented in SPIFlash.cpp. This function returns a verbose error message to the Serial console instead of the terse error codes of the previous version. The following functions have been deleted to enable bug fixes and uniformity in coding style. writeBytes() readBytes() They have been replaced with readByteArray() and writeByteArray(). v 2.0.0 BIG update in terms of speed. Sped up all functions atleast 25x Compatible with ATTiny85 All Read/Write/Erase functions can now take either (page number & offset) or (address) as arguments (Except readPage()) getAddress() can now return either a 32-bit address or a page number & offset - Refer to Readme.md The following functions are deprecated to enable compatibility with other AVR chips. _printPageBytes() printPage() printAllPages() readSerialStr() They can be used by uncommenting them in the SPIFlash.cpp file. However, be warned, this particular block of code has only been tested with the Arduino IDE (1.6.5) and only with 8-bit AVR based Arduino boards and will not be supported any further than v2.0.0 of this library