code: def clear_display_buffer(self):
          
          for row in range(0, 8):
              self.firmata.i2c_write(0x70, row * 2, 0, 0)
              self.firmata.i2c_write(0x70, (row * 2) + 1, 0, 0)
  
              for column in range(0, 8):
                  self.display_buffer[row][column] = 0
docs: Set all led's to off.