5 years, 6 months ago.

ST Link and custom board(Nucleo STM32L053)

Hi everybody,

I bought Nucleo STM32L053 board and started programming it with mbed. I tested my board with the already uploaded projects(Blinky, Hello World, etc.). Everything was ok. However, I have to carry out some experiments at the temperature above 50°C, which seems to be too much for Nucleo. So, I designed and ordered my own PCB with the same microcontroller and decided to debug my board with STLink(using mbed libraries). I simply looked at the Nucleo scheme and connected SWD signals, Rx and Tx from STLink to the same pins in the microcontroller(which is advised in the Nucleo manual). I removed CN2 jumpers and desoldered SB12 solder bridge. The same with GND and power supply. I left only Boot0 floating(mistake?) and there is no MCO signal on my board.

To load the flash memory, I used STLink Utility and according to command prompt, everything is ok. Utility verifies the software and everything seems to be correct. I could flash binary, 'Nucleo' drive is displayed as a drive in Computer folder and I can drag and drop there binaries. However, I don't get any message over COM port(TeraTerm), which I always had with Nucleo.

I read related topics, which had been posted here: https://developer.mbed.org/questions/3811/Prototype-to-Hardware-with-Nucleo/ http://developer.mbed.org/users/chris/notebook/prototype-to-hardware/ https://developer.mbed.org/forum/electronics/topic/5184/?page=1#comment-25504

Unofortunately, I didn't find any solution to my problem. Is there anyone, who encountered similar problem? Are BOOT0 and MCO necessary?

I'd appreciate any advice,

Greets, Andrzej

For execute code from flash, BOOT0 must be LOW ( < 0.14 * VDD), at least during the reset, when the state of the pin is latched. Simply connect this pin directly to GND (or by a resistor if you plan n.e. program the chip via the internal bootloader using serial port).

On pin MCO will be a particular signal only if properly run functionality in the software(and that's a rather work at a lower level than the mbed API).

I do not know why disconnect an SB12 bridge. It does not interfere that both the MCU is reset. Only it is important CN2. And if you are using a serial channel Nucleo I'd rather disconnected pin TX (SB63) Nucleo's MCU so as not to interfere.

I am also running the external nucleo-like boards and I had no problems with mbed and using Nucleo board as a programmer. Only difference is that I used a separate USB-serial converter( nb through which STM32 chips can be programmed entirely without STLINK or similar equipment).


posted by Nothing Special 11 Dec 2014


thank you for your post. You were right with connecting BOOT0 to GND. However, when I load Blinky project from mbed, it doesn't work, while the Blinky project from Keil works properly. So, it is probably a software problem.

Greets, Andrzej

posted by Andrzej Koziec 13 Dec 2014
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