Error Message ''Unknown Target Connected''

luis239955 · ‎2012-10-17

Posted on October 17, 2012 at 10:14

Hi Guys,

I have been playing with my STM32F4Discovery board for a few weeks now using the provided programs, but now I wrote one of my own and can not get it to work.

I am using some of the files form the IO_Toogle example, the program is compiling and Linking fine with no errors at the end. I have selected the STM32F407VG as the target.

When I try to load or even erase I get this error message: ''Unknown Target Connected''. same if I try to initiate a debug session.

When I try to run the original IO_Toggle program, it loads and runs perfectly.

I am at a loss here...

Any Help will be much appreciated, as I am pulling my hair out.

Best Regards

Luis

Linda · ‎2014-05-22

Posted on May 22, 2014 at 18:01

It was powered. The board should not be so fragile , right ? But cause the ''''Unknown Target Connected''; It worked well before. the JTAG device chain: TDO 0x0fffffff, under SW device, no cortex_M SW device found.

Thanks

Tesla DeLorean · ‎2014-05-22

Posted on May 22, 2014 at 18:35

The board should not be so fragile, right ?

Well you're operating without a safety net, the pins act as the fuse, if you didn't have the ground connected the potential might be more significant than 3V. There could have been other things going on. But you're not going to be able to push a button or change a software setting to fix it.

You need to get a scope and/or meter, and start looking at the board.

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Linda · ‎2014-05-22

Posted on May 23, 2014 at 02:06

Ok, I have scope and meter now, how to check it?

Thanks

Linda · ‎2014-05-22

Posted on May 23, 2014 at 02:12

I am able to connect the board by STM32 ST-LINK Utility, it says:

20:16:15 : ST-LINK Firmware version : V2J20S0 (Need Update)

20:16:15 : Old ST-LINK firmware detected!

Please upgrade it from ST-LINK->'Firmware update' menu.

20:16:15 : Connected via SWD.

20:16:15 : Connection mode : Connect Under Reset.

20:16:15 : Debug in Low Power mode enabled.

But can not connect it by Keil . On Keil, it can not detect ST-Link.

Thanks