How to enable and use RTC0, RTC1, and RTC2 -- nRF52832

RE: How to enable and use RTC0, RTC1, and RTC2 -- nRF52832

Sami — Fri, 30 Jun 2017 16:43:14 GMT

Thank you Kristin. I now know how to proceed with my nRF52823 application.

RE: How to enable and use RTC0, RTC1, and RTC2 -- nRF52832

FormerMember — Fri, 30 Jun 2017 10:34:58 GMT

It is not possible to have the LFCLK running when in system OFF, from the product specification: "System OFF is the deepest power saving mode the system can enter. In this mode, the system’s core functionality is powered down and all ongoing tasks are terminated."

RE: How to enable and use RTC0, RTC1, and RTC2 -- nRF52832

Sami — Wed, 28 Jun 2017 16:34:39 GMT

I'm not concerned with current consumption. My concern is that the RTC1 clock will stop running when the chip goes into "system OFF" mode. Is there a setting in the chip that can be issued that will allow the LFCLK to perpetually run even when we're in "system OFF" mode? In the past, how are developers creating a real-time clock that runs forever with the nRF52832 when the "system OFF" mode is shutting down the LFCLK?

RE: How to enable and use RTC0, RTC1, and RTC2 -- nRF52832

FormerMember — Wed, 28 Jun 2017 11:02:31 GMT

When setting the chip in SYSTEM ON mode, the RTC will keep running, unless it has been explicitly turned off. This chapter in the Product Specification shows the current consumption when the chip is in system ON, but the RTC is running.

RE: How to enable and use RTC0, RTC1, and RTC2 -- nRF52832

Sami — Tue, 27 Jun 2017 22:58:08 GMT

I'm currently using app_timer as my Real-time clock. However, when the processor goes into sleep mode, won't RTC1 will stop ticking away, thereby haulting my real-time clock? I must ensure that I have an RTC (either RTC1 or RTC2) that never stops ticking, even when the chip sleeps. Is there a register setting in the nRF52832 that I can activate that will by-pass reseting RTC1? Please advise...

RE: How to enable and use RTC0, RTC1, and RTC2 -- nRF52832

FormerMember — Mon, 26 Jun 2017 09:04:13 GMT

According to the product specification, the current consumption should only marginally increase when using multiple instances of the RTC..

With multiple instances of the RTC, different prescaler values used. To do so, you will have to use the RTC driver. If it is not necessary with different prescaler values, you can use app_timer. In that case, which timer you want to use depends on which one that is the best fit, API wise for example, for your application.

RE: How to enable and use RTC0, RTC1, and RTC2 -- nRF52832

Sami — Fri, 23 Jun 2017 17:20:17 GMT

Thank you Kristin. Is it recommended to simply use the Timer Library (based off of RTC1) to spawn as many timers as necessary? Are their advantages to using RTC2 and RTC1 simultaneously? Seems as though RTC2 running alongside RTC1 will increase power consumption.

RE: How to enable and use RTC0, RTC1, and RTC2 -- nRF52832

FormerMember — Thu, 22 Jun 2017 06:54:34 GMT

const nrf_drv_rtc_t rtc = NRF_DRV_RTC_INSTANCE(2); /**< Declaring an instance of nrf_drv_rtc for RTC2. */

RE: How to enable and use RTC0, RTC1, and RTC2 -- nRF52832

Sami — Wed, 21 Jun 2017 20:31:48 GMT

Thank you for your response Kristin. Unfortunately, I cannot find an example of how RTC2 is enabled within the SDK. Can you send a link my way ?

RE: How to enable and use RTC0, RTC1, and RTC2 -- nRF52832

FormerMember — Wed, 21 Jun 2017 09:01:27 GMT

When using the softdevice, RTC0 is blocked blocked by the softdevice, see this chapter in the softdevice specification. So your application is free to use RTC 1 and RTC 2. It should be possible to have three different instances of the RTC running.

For how to use and declare an instance of the RTC, you can have a look at the rtc example in the SDK.