I see that they arduino nano ble 33 support USB 2.0. Is there a way for us to create a USB mass storage of about 200kb for convenient storage of configuration files and history files? I see example arduino has UsbMassStorage but by default it only creates 1 disk with 512KB capacity. Which 512KB + 200KB bootloader is my chip error. Is there a way to reconfigure the capacity for UsbMassStorage? Thank you so much.

   This example exposes the second half (512KB) of Nano 33 BLE flash
   as a USB disk.
   The user can interact with this disk as a bidirectional communication with the board
   For example, the board could save data in a file to be retrieved later with a drag and drop

#include "PluggableUSBMSD.h"

void setup() {

  // write a file with some data
  // a+ means append, so every time the board is rebooted the file will grow by a new line
  FILE *f = fopen("/fs/data.txt", "a+");
  String hello = "Hello from Nano33BLE Filesystem\n";
  fwrite(hello.c_str(), hello.length(), 1, f);

void loop() {
  • which code are you talking about? ... please add the program listing to your question
    – jsotola
    May 13, 2023 at 16:29


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