simple timer?

RE: simple timer?

mr_creosote — Fri, 31 Mar 2017 15:37:02 GMT

thanks! have a good weekend. regards, mahesh

RE: simple timer?

Kenneth — Thu, 23 Mar 2017 09:25:33 GMT

Hi,

Feel free to comment out the PWRDWN calls, the timer interrupt will fire in any case.

Best regards,

Kenneth

RE: simple timer?

mr_creosote — Wed, 22 Mar 2017 14:11:40 GMT

Hi, I just need a timer -- i don't want the device to go to sleep. Is there a way to do that? Thanks! Mahesh

RE: simple timer?

Kenneth — Wed, 22 Mar 2017 09:21:30 GMT

Hi,

I think you can take a look at this:

http://www.nordicsemi.com/eng/Nordic-FAQ/All/How-to-setup-register-retention-mode-timer-on-on-the-nRF24LE1

The reason there is a "double" PWRDWN call in the while(1)-loop as shown below, is because the system will wakeup 1.5ms prior to the actual RTC wakeup tick. The system does so to startup the 16MHz crystal, to make sure the 16MHz crystal is running by the time the RTC wakeup tick occurs. During this 1.5ms period the CPU can go to standby to save current until the RTC wakeup tick occurs (another approach would be to use a flag in the whiel loop, and wait until the flag has been cleared in the RTC wakeup tick.

// Register retention mode

PWRDWN = 0x04;

// Standby mode (wait for interrupt)

PWRDWN = 0x07;

Best regards,

Kenneth