machine.Flash – Functions to control the 32 Mbit flash IC

The machine.Flash class contains all of the functions to read and write to the flash IC. Import it using

from machine import Flash

To see what’s contained inside the class you can use the help() command

help(Flash)

Functions

Flash.sleep()

• Puts the flash IC into deep sleep for saving power

• The flash IC will automatically be woken up if any of the flash operations below are called

Flash.erase(blockNum)

• Erases a 4kB block from the flash IC

    Flash.erase(0) # Erase block 0
    Flash.erase(5) # Erase block 5
  

• If no block number is given, the chip is fully erased. This can take a while

    Flash.erase() # Full chip erase can take up to 80 seconds
  

Flash.read(pageNum, rxBuffer)

• Reads the flash from the page number provided. Each page is 256 bytes long, therefore up to 256 bytes can be read at a time

    rx = bytearray(256)
    Flash.read(0, rx) # Read 256 bytes from page 0
  
    # Shorter amounts can also be read using a smaller buffer
    rx = bytearray(10)
    Flash.read(4, rx) # Read 10 bytes from page 4
  

Flash.write(pageNum, txBuffer)

• Writes to the flash at the page number provided. Each page is 256 bytes long, therefore up to 256 bytes can be written at a time

    tx = bytearray(256)
  
    for i in range(256):
        tx[i] = i # Populate some test data
      
    Flash.write(0, tx) # Write 256 bytes to page 0
      
    # Again, smaller amounts can also be written