what is the principle of converting Ticks in to seconds

[karan]

Hello

I am trying to change the ticks value of Battery measurement interval (ble_app-prox example) but i am not able to understand how the ticks period is measured based on what i understood from the example 1s is equal to 1000ms so totally we are setting it to120s then the ticks period is equal to 120000 if am wrong please correct me and explain me the correct method my aim to see the battery level changing based on the battery -measure_interval any help would be greatly appreciated

thankyou

[Susheel Nuguru]

Assuming you are using nRF51 and using APP_TIMER (RTC1).

You initialize the APP_TIMER using the prescaler. lets say that the prescaler is 0 then your timer generates 32768 ticks per second.

The macro given in app_timer.h converts the milliseconds to number of ticks.

#define APP_TIMER_TICKS(MS, PRESCALER)\
            ((uint32_t)ROUNDED_DIV((MS) * (uint64_t)APP_TIMER_CLOCK_FREQ, ((PRESCALER) + 1) * 1000))

Above you see that if MS = 120000 and prescaler 0, which is 120 seconds then you will get Ticks = ((120000*32768)/(0+1)*1000) rounded up to integer = 3932160 ticks. This is telling you that the timer will put 3932160 (0X3c0000) in RTC compare register and when RTC is started and is running for this many ticks, then it will be 120 seconds.

Does this answer your question?

[Susheel Nuguru]

I have run the SDK10 example and i also see the same thing what you saw. Will look into it now. Edit

I have now run the battery example on SDK 10 with usb and coin cell battery. You are right, the coin cell battery drops to 15% because the voltmeter shows 2.64V and according to battery_level_in_percent() this is 15%. If you want your battery level to behave differently, you need to change this function.