stm32 discovery external supply problem

[asecen89]

Posted on May 16, 2013 at 13:51

I would like to program my stm32 discovery board via st-link, to do this i am trying to power my board externally by using 5V pin. However, when i powered the board, ld1 com turns red, but it blinks. In this case, the program loaded in board runs, but i am not able to connect to it via st link; it gives an error that 'no target connected'. Do you have an idea about the problem here? 

#which-discovery-board?

[Tesla DeLorean]

Posted on May 16, 2013 at 14:07

Which Discovery board? ST makes about half a dozen different ones.

If you think it is the supply, use 5V from a bench supply, the USB supply has limited current available. Consider if you need to play with the SB (solder bridges), and the connectivity of RESET to your target device. Consider if the code on your target breaks SWD/JTAG connectivity by changing pin configurations, loops with SWI, or does DMA early in the start up process.

[asecen89]

Posted on May 16, 2013 at 14:26my board is stm32f4 and i am using a bench supply for 5V. I connected to board via usb and erased the chip so that pin configurations do not change.why does ld1 com blinks do you think? shouldn't it be always red? i could not find any information about it.

[asecen89]

Posted on May 16, 2013 at 14:26my board is stm32f4 and i am using a bench supply for 5V. I connected to board via usb and erased the chip so that pin configurations do not change.why does ld1 com blinks do you think? shouldn't it be always red? i could not find any information about it.

[agus_vilis]

Posted on January 30, 2015 at 14:13

Hello I have the same problem and i cant fix it!! there is no info on web. if somebody have any information please tell me. thank you very much!!!

[Tesla DeLorean]

Posted on January 30, 2015 at 15:57

Hello I have the same problem and i cant fix it!! there is no info on web. if somebody have any information please tell me. thank you very much!!!

Ok, but you haven't really contributed any information either. Did the board work at one time? What did you do immediately before the board failed? Have you reviewed the circuit diagram and looked at any voltages/signals on the board? What board do you have, and what have you connected to it?

[philipp23]

Posted on July 06, 2015 at 09:29

Hello,

I have a similar problem with my STM32L053-Discovery Board. If I connect the board via USB with my PC it works fine, but if I power supply the STM32L053 without my PC (battery), the LD1 (COM) starting to blink. I have connected the USB on the USB ST-Link connector. Thanks

[waheed901]

Posted on March 11, 2016 at 02:44Did anyone find the solution for this...I have a similar problem with my STM32F4 Discovery Board. If I connect the board via USB with my PC it works fine, but if I use power supply without my PC (bench supply), the LD1 (COM) start to blink. 

[Tesla DeLorean]

Posted on March 11, 2016 at 04:10

Did anyone find the solution for this...

Well that would require someone with these issues and motivation to actually do some analysis. My guess would be that the ST-LINK firmware blinks the LED because it is powered, but has no USB connectivity. Does this actually have any deleterious effect? If not, who cares? If the ST-LINK does something weird in this condition, disconnect it from the target CPU at the SWD and NRST interfaces.

[waheed901]

Posted on March 11, 2016 at 07:03

Though it is not causing any error and the program executes fine.

I like your comment ''WHO CARES'' .......