RE: nrf_drv_timer_capture not returning correct value

haakonsh — Thu, 17 Sep 2020 10:48:45 GMT

It returns the number of ticks of the timer, not microseconds. Read the implementation of nrf_drv_timer_capture instead of making false assumptions.

RE: nrf_drv_timer_capture not returning correct value

Prayjit — Wed, 16 Sep 2020 16:01:26 GMT

Below are timer settings from sdk_config.h

// <e> NRFX_TIMER_ENABLED - nrfx_timer - TIMER periperal driver
//==========================================================
#ifndef NRFX_TIMER_ENABLED
#define NRFX_TIMER_ENABLED 1
#define TIMER_ENABLED      1
#endif
// <q> NRFX_TIMER0_ENABLED - Enable TIMER0 instance

#ifndef NRFX_TIMER0_ENABLED
#define NRFX_TIMER0_ENABLED 1
#define TIMER0_ENABLED      1
#endif

// <q> NRFX_TIMER1_ENABLED - Enable TIMER1 instance

#ifndef NRFX_TIMER1_ENABLED
#define NRFX_TIMER1_ENABLED 1
#define TIMER1_ENABLED      1
#endif

// <q> NRFX_TIMER2_ENABLED - Enable TIMER2 instance

#ifndef NRFX_TIMER2_ENABLED
#define NRFX_TIMER2_ENABLED 0
#define TIMER2_ENABLED      0
#endif

// <q> NRFX_TIMER3_ENABLED - Enable TIMER3 instance

#ifndef NRFX_TIMER3_ENABLED
#define NRFX_TIMER3_ENABLED 1
#define TIMER3_ENABLED      1
#endif

// <q> NRFX_TIMER4_ENABLED - Enable TIMER4 instance

#ifndef NRFX_TIMER4_ENABLED
#define NRFX_TIMER4_ENABLED 1
#define TIMER4_ENABLED      1
#endif

// <o> NRFX_TIMER_DEFAULT_CONFIG_FREQUENCY - Timer frequency if in Timer mode

// <0=> 16 MHz
// <1=> 8 MHz
// <2=> 4 MHz
// <3=> 2 MHz
// <4=> 1 MHz
// <5=> 500 kHz
// <6=> 250 kHz
// <7=> 125 kHz
// <8=> 62.5 kHz
// <9=> 31.25 kHz

#ifndef NRFX_TIMER_DEFAULT_CONFIG_FREQUENCY
#define NRFX_TIMER_DEFAULT_CONFIG_FREQUENCY 0
#endif

// <o> NRFX_TIMER_DEFAULT_CONFIG_MODE - Timer mode or operation

// <0=> Timer
// <1=> Counter

#ifndef NRFX_TIMER_DEFAULT_CONFIG_MODE
#define NRFX_TIMER_DEFAULT_CONFIG_MODE 0
#endif

// <o> NRFX_TIMER_DEFAULT_CONFIG_BIT_WIDTH - Timer counter bit width

// <0=> 16 bit
// <1=> 8 bit
// <2=> 24 bit
// <3=> 32 bit

#ifndef NRFX_TIMER_DEFAULT_CONFIG_BIT_WIDTH
#define NRFX_TIMER_DEFAULT_CONFIG_BIT_WIDTH 0
#endif

// <o> NRFX_TIMER_DEFAULT_CONFIG_IRQ_PRIORITY - Interrupt priority

// <0=> 0 (highest)
// <1=> 1
// <2=> 2
// <3=> 3
// <4=> 4
// <5=> 5
// <6=> 6
// <7=> 7

#ifndef NRFX_TIMER_DEFAULT_CONFIG_IRQ_PRIORITY
#define NRFX_TIMER_DEFAULT_CONFIG_IRQ_PRIORITY 6
#endif

I am assuming that nrf_drv_timer_capture returns time in mirco seconds ; for example 2-3 sec it returns 55-60 sec

RE: nrf_drv_timer_capture not returning correct value

haakonsh — Wed, 16 Sep 2020 08:33:40 GMT

What are the default TIMER configurations in your sdk_config.h?

What values did you capture and what did you expect to capture?

Can you share more information on how you've set up your experiment?