File doesn't appear in explorer

09 Apr 2018

Hello, I have a program for my LP1768 wich write in a file:

LocalFileSystem    local("local");
int main() {
  FILE                *fp;
  fp = fopen("/local/data.dat", "w+");
  fprintf(fp,"AXE1 x=%d y=%d z=%d\n\r",MMA1.x,MMA1.y,MMA1.z); //

My problem is that this file (data.dat) is invisible in my files explorer under W10, I can see the MBED drive but my file is not visible. Thanks for your help


21 Apr 2018


the MBED drive you see in windows 10 is from the debugger and not from the µC and you can't write a file from the µC to the debuggers drive. The MBED drive from the debugger is only there to flash the µC. If you want to play with files use a SD-Card, external Flash or an EEPROM.



The mbed NXP LPC1768 is one of a range of mbed Microcontrollers packaged as a small 40-pin DIP, 0.1-inch pitch form-factor making it convenient for prototyping with solderless breadboard, stripboard, and through-hole PCBs. It includes a built-in USB programming interface that is as simple as using a USB Flash Drive. Plug it in, drop on an ARM program binary, and its up and running!

BTW: if you want to write on a file system you need to mount the drive in your code. Search for examples i.e. Mbed-Bootloader. I hope this helps!