9 years, 5 months ago.

F401RE serial port printf doesn't work

I just bought an Nucleo F104RE board and upgraded STLINK firmware to V2.J23.M6. Also upgraded the V2 driver on windows 7.

I can see the Nucleo drive. /media/uploads/mrunmoy/nucleo_drive.png

I built a simple Hello, World code from mbed.org online compiler. /media/uploads/mrunmoy/code.png

Saved the bin file in a directory. Copied the bin file into the Nucleo drive. When I go out of the drive and come back in, the file is gone! This happens everytime.

When I disconnect the USB cable and then reconnect it. I can't see the file.

Whatever code I downloaded into the drive, does not execute.

Although the Nucleo drive shows 512KB of 528KB full and the file I was copying was of 14KB. /media/uploads/mrunmoy/drivesize.png

I deleted all the files and then I pasted the binary. This time it executed the code but no output on the virtual com port. only led blinks. I added a printf("Hello, world!\n"); to the above code though.

Now I uplug the nucleo board from the usb port and plug it back in. I dont see the file any more and I see all the files I deleted back in there!

What am I doing wrong? Doesn't Nucleo work like other mbed platforms? I have a LPC1768 and I just build and copy the bin file into the mbed drive. reset the board and it executes the binary! easy!

A simple code

1. include "mbed.h"

Serial pc(SERIAL_TX, SERIAL_RX);

DigitalOut myled(LED1); int main() { int i = 1; pc.printf("Hello World !\n"); while(1) { wait_ms(1000); pc.printf("This program runs since %d seconds.\n", i++); myled = !myled; } }

doesn't print anything on the serial port, no matter how many times I upgrade the mbed library.

Please help!

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Last updated: 20 Apr 2021

NUCLEO-F401RE

Affordable and flexible platform to ease prototyping using a STM32F401RET6 microcontroller.