SPI Flash memory cannot be overwritten directly; it must be erased in sectors or blocks first. Sending an Erase command resets the targeted memory bits back to a value of 0xFF . 4. Writing & Verifying
Most SPI Flash chips operate strictly at . Connecting them directly to the 5V digital I/O pins of an Arduino Uno or Nano will permanently destroy the chip. Use one of the following methods to safely drop the voltage: spi flash programmer arduino