Read value on EXT pin thingy 52

RE: Read value on EXT pin thingy 52

Guojun Wang — Mon, 04 May 2020 15:24:30 GMT

You are welcome!

RE: Read value on EXT pin thingy 52

Rilleaa — Mon, 04 May 2020 15:20:04 GMT

Okey thank you very much for the help guwa!

//Rilleaa

RE: Read value on EXT pin thingy 52

Guojun Wang — Mon, 04 May 2020 15:05:55 GMT

I think it is better to enable pin level interrupt with GPIOTE and make use of interrupt handler to sample the ADC.

In this case, the application doesn't have to actively reading pin levels all the time, and the CPU can go to sleep and only wakes up on interrupt.

RE: Read value on EXT pin thingy 52

Rilleaa — Mon, 04 May 2020 14:53:17 GMT

Thank you!

Yes i must have misunderstood the function and when i did as you recomended the while loop work as i intended.

Can i ask you another question?

At the moment i use the function as follows in the code bellow. What i want to do is get data from an adc when new data is ready witch is indicated by pulling the pin low. Would the code bellow be a good way of using the function drv_ext_gpio_pin_read() to wait for that indication that new data is ready or could it be used in a more effict way?

    uint32_t pinvalue;

    while(pinvalue != 0 ){

        //do nothing
    
        drv_ext_gpio_pin_read(SX_IOEXT_1, &pinvalue);

        
    }

//Rilleaa

RE: Read value on EXT pin thingy 52

Guojun Wang — Mon, 04 May 2020 14:08:13 GMT

Hi Rilleaa,

I think you may have misunderstood the usage of this function drv_ext_gpio_pin_read(uint32_t pin_number, uint32_t * const p_pin). The second argument is passed in to store the pin levels.

If pin level is read successfully, drv_ext_gpio_pin_read will return DRV_EXT_GPIO_STATUS_CODE_SUCCESS (0x00), otherwise it will return values other than 0.

Once this function returns SUCCESS, then you check the pin level stored in pointer p_pin.

In case it still does not work, you can debug it by setting input pin with PULL UP and read the level again. It should be 1 in this case.

Hope this will help you!