Interrupt based temperature sensor on nrf52840 using SDK v15.0.0

RE: Interrupt based temperature sensor on nrf52840 using SDK v15.0.0

Vidar Berg — Wed, 23 May 2018 12:35:18 GMT

Hi,

yes, you can divide temp by 4 to get decimal points:

int temp;
float temp_float;
(void)sd_temp_get(&temp);

temp_float = temp * 0.25f;

NRF_LOG_INFO("Temperature: " NRF_LOG_FLOAT_MARKER , NRF_LOG_FLOAT(temp_float));

Note that the resolution is 0.25C and the accuracy (offset) is +- 5C, so you may want to consider using an external temperature sensor if you plan on measuring ambient temperature. http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52840.ps/temp.html?cp=2_0_0_5_27_1_0#unique_2060644509

RE: Interrupt based temperature sensor on nrf52840 using SDK v15.0.0

Sridhar Jonnavittula — Wed, 23 May 2018 06:05:39 GMT

Hi,

I have used sd_temp_get() and it is working. My another concern is : Is there any way to get temperature value in two decimal points like (25.46 instead of only 25)?

Thanks

RE: Interrupt based temperature sensor on nrf52840 using SDK v15.0.0

AmbystomaLabs — Tue, 22 May 2018 14:52:41 GMT

If you are running the SD the easiest way to get the temp is via the API.

static int32_t temp;

err_code = sd_temp_get(&temp);
APP_ERROR_CHECK(err_code);

Though if you want precise timing driven temp measurements using an interrupt then the HTS example apparently does this using the registers and sends the data on BLE.