I am turning on/off a LED using HAL_GPIO_WritePin() but still one of the LED showing dim even though its being RESET. any idea?

[Peter BENSCH]

Then a small current flows, which may well cause the LED to glow. Unfortunately, you have not included any initialisation code, but I suspect that one of the internal pull resistors is switched on or that current is flowing externally. What does your hardware look like around the LED?

Regards

/Peter

[cjaya.2]

 GPIO_InitStruct.Pin = GPIO_PIN_12|GPIO_PIN_13|GPIO_PIN_14|GPIO_PIN_15
                          |GPIO_PIN_4|GPIO_PIN_8|GPIO_PIN_9;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

The GPIO_PIN_15 connected to the LED is showing dim light on even though is reset.

[Peter BENSCH]

And what about the hardware, i.e. the schematics around the LED?

How is it connected to the voltage?

[Kamil Duljas]

You have NOPULL - It means can pick up noise. Try set GPIO_PULLDOWN for GPIO_InitStruct.Pull

[Bob S]

WHAT??????? That is nonsense. The pin is defined as out push-pull output. It will drive high or drive low. Enabling the internal pull up or pull down will only draw more current.

[Kamil Duljas]

You right . I mistake with open drain. Soooorrrry :)​