the built in led of stm32l4r9 discovery kit works plus led attached to other gpios don't work

[kanuz_khan]

i'm using stm32l4r9 discovery kit and the built in led of stm32l4r9 discovery kit works but led attached to other gpios don't work. no mater if i set or rest it.

[SofLit]

You need to have this config for PH4:

GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_LOW;

GPIO_InitStruct.Pin = GPIO_PIN_4;
HAL_GPIO_Init(GPIOH, &GPIO_InitStruct);

[kanuz_khan]

this is for the built in led 

/*Configure GPIO pins : MIC_VDD_Pin DSI_SPI_USART_CS_Pin greenled_Pin */

GPIO_InitStruct.Pin = MIC_VDD_Pin|DSI_SPI_USART_CS_Pin|greenled_Pin;

GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;

GPIO_InitStruct.Pull = GPIO_NOPULL;

GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;

HAL_GPIO_Init(GPIOH, &GPIO_InitStruct);

 and this for the external 

/*Configure GPIO pin : external_led_Pin */

GPIO_InitStruct.Pin = external_led_Pin;

GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;

GPIO_InitStruct.Pull = GPIO_NOPULL;

GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;

HAL_GPIO_Init(external_led_GPIO_Port, &GPIO_InitStruct);

external is pd8 and built in is ph4

[kanuz_khan]

ph4 works perfectly fine its pd8 thats not working. thank you so much for helping out

[SofLit]

Could you please verify if PH4 is set for greenled_Pin in CubeMx?

Did you remove the serial resistor connected to the green LED (I think R5)?

[SofLit]

Next time please be more specific on the issue .. Your problem description is confusing.

Now for PD8:

- Check the connections using continuity between the LED and GPIOD8.

- external_led_Pin: does it correspond to GPIO_PIN_8?

- external_led_GPIO_Port: does it correspond to GPIOD?

- HAL_GPIO_WritePin(external_led_GPIO_Port, external_led_Pin, GPIO_PIN_RESET); try to toggle it instead of writing a value. I suspect that the external LED is pulled down to GND and not pulled up to the VDD like Green LED.

[gbm]

Your code in main() does not toggle PD8. Also, if you give a symbolic name to the pin, use that name and port name while setting it.

[kanuz_khan]

i've checked the continuity its fine but there is no voltage change on d13 even after toggling it every 2 seconds inside the while loop in main the voltage remains same i.e 0.2 volts on the pin

[kanuz_khan · Accepted solution]

On the documentation it states d13 as PB13?
the positive leg of the led is attached to 3.3v and the negative to d13 i just added a resistor equal to r5 on between ground and negative le and its working now