Cannot connect to Board anymore

[schellek]

Hi,

i designed a board with a STM32F030 and already flashed and debugged it with success. However i used a Nucleo Board in order to flash it and I cannot connect to the target anymore. I also want to mention that i used the regular ST-LINK V2 as well. I already tried to power the target, while bridging BOOT0 to +3V3 and I also tried to erase the memory with ST-Util. In fact nothing works (OpenOCD, ST-UTIL, texane st-util Command Line Tool...). I already checked some threads with similar problems, however I couldn't find a solution so far. Has anyone else had a problem like this?

[Tesla DeLorean]

Try accessing the system boot loader via the serial port.

What does your code actually do that could break this? Go into low power modes, reconfigure GPIOA pins, disable debug?

[schellek]

Wow, thank you for the quick response. I will try that later. I wonder if the initialization of the HSE is the trigger, since i‘m providing a Clock Signal to GPIOF.

rcc_osc_on(RCC_HSI);

rcc_wait_for_osc_ready(RCC_HSI);

rcc_set_sysclk_source(RCC_HSI);

rcc_set_hpre(RCC_CFGR_HPRE_NODIV);

rcc_set_ppre(RCC_CFGR_PPRE_NODIV);

flash_prefetch_enable(); flash_set_ws(FLASH_ACR_LATENCY_000_024MHZ);

rcc_periph_clock_enable(RCC_GPIOF);

rcc_osc_on(RCC_HSE);

rcc_wait_for_osc_ready(RCC_HSE);

rcc_set_sysclk_source(RCC_HSE);

rcc_ahb_frequency = 16000000;

rcc_apb1_frequency = 16000000;

rcc_apb2_frequency = 16000000;

rcc_periph_clock_enable(RCC_GPIOA);

rcc_periph_clock_enable(RCC_GPIOB);

rcc_periph_clock_enable(RCC_ADC);

rcc_periph_clock_enable(RCC_SYSCFG_COMP);

rcc_periph_clock_enable(RCC_I2C1);

rcc_set_i2c_clock_hsi(I2C1); 

[berendi]

Try connecting with the reset signal active (low) while connecting to the board, then release reset immediately when the debugger connects. Might require a few tries, but it should eventually work.

[schellek]

I tried accessing the bootloader, but without any success.

I bridged BOOT0 to +3V3, then I pressed the Reset Button - Is there a step missing?

However, refering to the bootloader manual, there is a given configuration for the bootloader over USART1 on PA14/PA15 or PA9/PA10. The USART1 of the STM32F030K6 is on PA2/PA3 - https://www.st.com/content/ccc/resource/technical/document/application_note/b9/9b/16/3a/12/1e/40/0c/CD00167594.pdf/files/CD00167594.pdf/jcr:content/translations/en.CD00167594.pdf

I used the Flash Loader Demonstrator or HTerm, in order to send the commands

[oeliks]

Your problem is probabbly hardware related. You dont have 10k resistor nrst-vcc. In this case programming under reset should work - connect reset from st link to nrst.

[schellek]

@oeliks The uC has an Internat Pull up Resistor, however i try it tomorrow, thank you.

[berendi]

USART1 can be mapped to PA2/PA3, PA14/PA15, PA9/PA10, or PB6/PB7. Of these, the bootloader is monitoring only PA10 and PA15 for commands. It doesn't matter which possible mapping is used in the application, because it isn't running at all.