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STM32F4 Discovery not working without reset

vaibhav23
Associate II
Posted on January 23, 2012 at 18:50

I have an STM32F4 Discovery board; recently I just had uploaded some code pertaining to the PWM example where I made PD12-15 some PWM signal so I could see it working with the LEDs on board.

The program uploaded and now the board is not detected unless I hold the reset button. In Windows the device is said to be unknown. When holding the reset button the device comes up and after uploading the discovery code it does not change the behavior of the board.

Without pressing the reset button the board just acts the same no matter how much I program it.

Any help would be appreciated.

Thanks.

#stm32f4 #user-code-blocking-st-link #pwm-output #stm32f4discovery
3 REPLIES 3
Posted on January 23, 2012 at 19:43

Adjust the BOOT0 connection so that it goes high, the board will no longer run your broken code at reset. Doing this will confirm if the problem is with your code, or one with the board. Absent some code to look at, I'd wager the former.

Fix or address the issues with your code, and then the ST-LINK portion should work properly all the time.

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vaibhav23
Associate II
Posted on January 24, 2012 at 05:22

Hi thanks for the reply...so it looks like I can upload code when I pull up the BOOT0 I managed to put the default discovery binary and it uploaded. But I am still having the same problem, although the discovery code seems to work, for one of LEDs it does not. It is the BLUE LED which is PD15.

Update: I put the audio example now the LD1 is extremely dim when I plug in the USB cable, if I hold the reset button the LED lights up properly.

vaibhav23
Associate II
Posted on January 24, 2012 at 08:23

Ok I think I figured out the problem. It looks like the 3V regulator is toast, the board seems to work correctly if I provide an external 3.3V input.

Thanks for all your help.