Measuring 1hz to 1Mhz Input frequency on up to 6 GPIOs with maximum possible high accuracy.

RE: Measuring 1hz to 1Mhz Input frequency on up to 6 GPIOs with maximum possible high accuracy.

frogrammer — Thu, 23 Jan 2025 02:54:55 GMT

Also, i have checked the code with PWM input which works fine and stable. That PWM code i have found from one of your GitHub links. https://github.com/sigurdnev/ncs-playground/blob/master/samples/pulse_detector/src/main.c

I just had to adjust NRF_P0 instead of NRF_GPIO. Finally, i checked with different Frequency Generation to Detection.

Another question is, can I just make 6 instances of this code with different DPPI channels, Timers CC? Sigurd

Will all these instances affect BLE or I2C?

RE: Measuring 1hz to 1Mhz Input frequency on up to 6 GPIOs with maximum possible high accuracy.

frogrammer — Wed, 22 Jan 2025 16:57:48 GMT

I do not have a logic analyser.

right now my input frequency is coming from a Schmitt trigger output so I will try to check with a PWM input from another nrf microcontroller.

RE: Measuring 1hz to 1Mhz Input frequency on up to 6 GPIOs with maximum possible high accuracy.

Sigurd — Wed, 22 Jan 2025 16:41:19 GMT

Hi!

Do you have a logic analyzer to check what the frequency deviation actually is? e.g. a saleae logic analyzer.

RE: Measuring 1hz to 1Mhz Input frequency on up to 6 GPIOs with maximum possible high accuracy.

frogrammer — Tue, 21 Jan 2025 23:01:08 GMT

Thank you so much for the code. I appreciate your time. However, I have tested this frequency measurement based on Counting pulse at 100ms and it varies +- 150 at only 105KHz.

Average freq: 105420 [Hz]
C: 10542
Average freq: 105440 [Hz]
C: 10544
Average freq: 105430 [Hz]
C: 10543
Average freq: 105440 [Hz]
C: 10544
Average freq: 105420 [Hz]
C: 10542
Average freq: 105410 [Hz]
C: 10541
Average freq: 105390 [Hz]
C: 10539
Average freq: 105380 [Hz]
C: 10538
Average freq: 105390 [Hz]
C: 10539
Average freq: 105370 [Hz]
C: 10537
Average freq: 105330 [Hz]
C: 10533
Average freq: 105350 [Hz]
C: 10535
Average freq: 105370 [Hz]
C: 10537
Average freq: 105330 [Hz]
C: 10533
Average freq: 105320 [Hz]
C: 10532
Average freq: 105330 [Hz]
C: 10533

The variations are quite rough. Is it the highest limit of an nRF5340?

Although, I didn't provide the pin 28 a stable known frequency but my current setup did result stable frequency measurement on an Arduino Uno mini like this :-

 1. 13:58:25.443 -> 110344.83
 2. 13:58:25.803 -> 110344.83
 3. 13:58:26.079 -> 110344.83
 4. 13:58:26.423 -> 110344.83
 5. 13:58:26.716 -> 110344.83

RE: Measuring 1hz to 1Mhz Input frequency on up to 6 GPIOs with maximum possible high accuracy.

Sigurd — Tue, 21 Jan 2025 22:23:59 GMT

Hi!

Try this:

devzone.nordicsemi.com/.../pulse_5F00_counter.rar

Connect a jumper-wire between P0.05 and P0.28 to test.

RE: Measuring 1hz to 1Mhz Input frequency on up to 6 GPIOs with maximum possible high accuracy.

frogrammer — Tue, 21 Jan 2025 14:15:20 GMT

I have tried your program,

It didn't run properly on NCS 2.6.1 , it showed :

error: NRFX_GPIOTE (defined at C:/ncs/v2.6.1/zephyr/modules/hal_nordic\nrfx/Kconfig:70,
modules\hal_nordic\nrfx/Kconfig:70) is assigned in a configuration file, but is not directly user-
configurable (has no prompt). It gets its value indirectly from other symbols. See
http://docs.zephyrproject.org/latest/kconfig.html#CONFIG_NRFX_GPIOTE and/or look up NRFX_GPIOTE in
the menuconfig/guiconfig interface. The Application Development Primer, Setting Configuration
Values, and Kconfig - Tips and Best Practices sections of the manual might be helpful too.
Parsing C:/ncs/v2.6.1/zephyr/Kconfig
Loaded configuration 'C:/ncs/v2.6.1/zephyr/boards/arm/nrf5340dk_nrf5340/nrf5340dk_nrf5340_cpuapp_defconfig'
Merged configuration 'C:/ncs/test/count_pulse/prj.conf'

Also, It couldn't find

#include <drivers/gpio.h>
#include <zephyr.h>
#include <logging/log.h>

So, I have changed header files to

#include <zephyr/kernel.h>
#include <zephyr/device.h>
#include <zephyr/logging/log.h>
#include <zephyr/drivers/gpio.h>

Would you mind checking it?

RE: Measuring 1hz to 1Mhz Input frequency on up to 6 GPIOs with maximum possible high accuracy.

Sigurd — Tue, 21 Jan 2025 13:27:23 GMT

Hi!

I made an example here some years ago:

https://github.com/sigurdnev/ncs-playground/blob/master/samples/pulse_detector/src/main.c