2 Replies Latest reply on Sep 26, 2014 11:43 AM by ArvindS_76

    [20737S] Wrong GPIO behavior on P27 or P14

    hachc_2137126

      Hi,

      One weird finding on using GPIO pin as LED control.

      The symptom is found at using P27/PWM1 or P14/PWM2 as GPIO function for driving the LED.

      The GPIO pin state won't stay at low (to turn on the LED) statically while we programmed it to be low from API:

       

      #define GPIO_PIN_LED1 14

      #define GPIO_SETTINGS_PIN_LED1 (GPIO_OUTPUT | GPIO_INIT_HIGH | GPIO_LED)

      ....

      gpio_configurePin (GPIO_PIN_LED1 / 16, GPIO_PIN_LED1 % 16, GPIO_OUTPUT_ENABLE, 0);

       

        It behaves as a short-period 'low' then back to high. So the LED will be just a short and dim blinking in every call of API gpio_configurePin (we configure it in every second).

       

        But we don't see this issue while changing the PIN to P13/PWM3.

       

      HW setting:

      VDDIO: 1.8v (also the same voltage level for LED)

      Resistor for LED: 100 ohm

       

        Any comment?