Problem in understanding RTC

[adrianwong]

Hi, can anyone explain to me about this example in this link with details : github.com/.../main.c I'm a newbie in nordic and i found it difficult to understand this example. Kindly assist and reply asap. Thanks!

[awneil]

Indeed - it is difficult to assist when it's not clear what assistance you require!

You say you are "a newbie in nordic" - do you have any prior programming experience at all? Do you have any prior experience with microcontrollers?

[adrianwong]

Hi , what i need is can you put details comments beside the every line of the code that i sent. Then from there i can slowly figure out what is actually happen in the code. Thanks. By the way, plus what kind of output can i expect? Currently, the code running and displayed "4, 2 , 1, 1, 1, 1, 1, 1, 1, 1, 1" by checking through serial terminal. Then it stop forever.

[awneil]

The comments in the code look pretty detailed already.

[adrianwong]

From the code itself, how can i change the RTC interval to 1s? THrough my calculation i couldn't get what i want. Kindly assist.

[Ole Bauck]

With prescaler 0, the RTC will run at 32.768 KHz which means 32768 counts per second. This means that the CC[0] needs to be initialized and incremented with 32768 instead of 1000. I suggest that you read the Reference Manual chapter about RTC to get a better understanding of how it works.

[adrianwong]

What you mean is by putting NRF_RTC0->CC[0] = 32768 when NRF_RTC0->PRESCALER = 0 then the IRQ handler will trigger every 1s right? Nope, this is not working.