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Associate II
May 16, 2025
Solved

STM32WB09 Nucleo SPI clock problem

  • May 16, 2025
  • 1 reply
  • 405 views

Hello,

I'm having an issue with the SPI clock on the NUCLEO MB2032 board. As you can see in the image, I only have the debugger connected, and the clock signal isn't completely square.

In the code, the only thing I'm running is the following:

const uint8_t EEPROM_RDSR = 0b00000101;

while(1){
      HAL_SPI_Transmit(&hspi3, (uint8_t *)&EEPROM_RDSR, 1, 100);
}

What I'm measuring with the oscilloscope is pin SB14, which, according to the PCB file provided by ST, is directly connected to the SPI clock.

ManuelIgnacio_0-1747415063328.png

 

ManuelIgnacio_1-1747415200222.png



ManuelIgnacio_3-1747415311363.jpeg

ManuelIgnacio_4-1747415355250.png

ManuelIgnacio_5-1747415369456.png

 

 

Best answer by TDK

Ensure pin speed for the SPI pins is set to VERY HIGH FREQUENCY or whatever the highest is for your chip.

1 reply

TDK
TDKBest answer
Super User
May 18, 2025

Ensure pin speed for the SPI pins is set to VERY HIGH FREQUENCY or whatever the highest is for your chip.

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Associate II
May 19, 2025

Thank you very much for your help, TDK. I solved the problem by checking for inconsistencies in the SPI configuration. I set a prescaler of 32 (baud rate = 1000 KBits/s), and it started generating a clean square wave signal.

I tried setting the clock pin to the maximum frequency, but the signal still looked inconsistent (not like a proper square wave).