Read Chip Temperature Sensor on nrf52832

[alima]

Hello,

I am trying to read the internal temperature sensor using interrupts (SoftDevice is disabled). This is what I have:

#include "nrf_temp.h"
#include "nrf_nvic.h"

static int32_t g_temp_reading;

void TEMP_IRQHandler()
{
    NRF_TEMP->EVENTS_DATARDY = 0;
    g_temp_reading = (nrf_temp_read() / 4);
    NRF_TEMP->TASKS_STOP = 1;
}

void init()
{
    nrf_temp_init();

    g_temp_reading = 0;

    NRF_TEMP->INTENSET |= TEMP_INTENSET_DATARDY_Enabled;

    sd_nvic_SetPriority(TEMP_IRQn, APP_IRQ_PRIORITY_LOW);
    sd_nvic_EnableIRQ(TEMP_IRQn);
}

void get_temperature()
{
    NRF_TEMP->TASKS_START = 1;
}

For some reason it never gets into "TEMP_IRQHandler()"

Could you please help me understand what I am doing wrong?

Thank you in advance.

[Simonr]

Hi

Are you calling any of these functions in your main(void) function? I suggest you take a look at our temperature example to see how it is done there. It can be found in this path when you have downloaded our SDK: \nRF5_SDK_15.2.0_9412b96\examples\peripheral\temperature

Best regards,

Simon

[alima]

Hello Simonr,

Thanks for your reply.

I have based my implementation on that example. Also, I am calling those functions: first init() and then get_temperature(). I have verified this with GDB. I have set breakpoints for these 3 functions and I see how init() and get_temperature() are called, but TEMP_IRQHandler() is never called.

[Simonr]

Hi Alfonso

It seems you are calling a few SoftDevice functions, but I don't see that you have enabled the SoftDevice. Please see the nrf_sdh_enable_request() function in nrf_sdh.c for how to do this.

Best regards,

Simon

[alima]

Hi Simonr,

That's true, I haven't enabled the SD, but I am actually trying to read this sensor without SD enabled. Do you know how I can do that? I have been looking into the documentation and couldn't find anything.

Thanks in advance.

Best regards,

Alfonso

[Simonr]

The temperature example states: 

/* Busy wait while temperature measurement is not finished, you can skip waiting if you enable interrupt for DATARDY event and read the result in the interrupt. */

You have to enable DATARDY in order to read the temperature by using interrupt.

Best regards,

Simon