Thank you answer .

I have forgotten to write The CPU of STM32 becomes hot.

my program is working before does not work. first does not work program

1. include "mbed.h"

PwmOut k(D15); Serial pc(USBTX, USBRX); DigitalOut myled(LED1); char i; long long a; int j; int main() { pc.printf("START"); k.period_ms (15);

k.pulsewidth_us (1000); wait(3.0);

k.pulsewidth_us (1200); wait(10); a=1000; while(1)

{ i=pc.getc();

if(i=='1'){ a+=1; i=0; pc.printf("up"); }

else if(i=='2') {a=a-1; i=0; pc.printf("down"); } else if(i=='3') {a=1000; i=0; pc.printf("STOP"); } else { pc.printf("no"); } k.pulsewidth_us (a); } }

second, I try easy program. But, don't flash LED.

1. include "mbed.h"

DigitalOut led (LED1); int main() { while(1) { led=1; wait(1.0); led=0; wait(1.0); } }

Hi Clark,

If the blink example doesn't work than that's not a good sign :(

Are you able to program the board with the blinky example? Or are you getting the FAIL.TXT?

Thanks, Brian

Thank you comment, I can program blinky example, But,now I am not getting the FAIL.txt. STM32 is hot now. and the board not connect anything without USBminiB.

Ok, it sounds like your board may be having hardware issues. The last thing I would try to recover would be to reflash the ST-Link firmware, which you can get from here: http://www.st.com/content/st_com/en/products/embedded-software/development-tool-software/stsw-link007.html

But other than that I'm not really sure of the next steps. You could always contact ST about it but it may be easier to just try a different board if you have it.

-Brian

Thank you anser I decide to buy new STM32 board.