Frequency Measurement / Signal Measurement

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Akhileswar_B
Level 1
Level 1
First question asked Welcome!

Issue :: Precision of the frequency measured is affected at higher rates of input(example: 2KHz)

I am using a input tick frequency of 62500 in my ICU config. I can use higher rate of tick freq. but in that case I will not be able to measure lower frequency, below are more details with tick frequency info.

62500 - I can measure from 1Hz 

12500 - I can only measure from 2Hz

250000 - I can only measure from 4Hz.

I want to improve my accuracy at higher frequency rates with optimal tick frequency where I will be able to measure 1Hz as well.

Please suggest regarding the same.

Thankyou

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1 Solution
JJack
Level 5
Level 5
Associated Partner - Distributor Rutronik
5 questions asked 25 likes received 100 sign-ins

Hi Akhileswar_B,

from what you write I am making an educated guess:

  • You are actually measuring the period duration of a signal and calculating the frequency from that
  • You are using a counter/timer with 16 bit. This fits to ~65536 ticks are 1s (1 Hz) and so on

My proposal for you is to switch to a 32-bit timer so you can measure longer periods without timer overrun and have a higher tick freq.

Traveo2 has both 16 and 32 bit TCPWM. To find out the timers with 32-bit resolution please check the datasheet, chapter Peripheral I/O-map. Here is an example:

Ralf_0-1641369187920.png

Best regards

Ralf

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2 Replies
Ashish
Moderator
Moderator
Moderator
25 likes received 50 solutions authored 100 replies posted

Hi,

Can you please give a more clear description of the issue, and your setup. Kindly mention which board , MCU are you using, what is the project about, what things (i.e. which peripherals) are being used, possible screenshots of the issue and code snippet to help us understand the issue better?

Thanks,

Ashish

0 Likes
JJack
Level 5
Level 5
Associated Partner - Distributor Rutronik
5 questions asked 25 likes received 100 sign-ins

Hi Akhileswar_B,

from what you write I am making an educated guess:

  • You are actually measuring the period duration of a signal and calculating the frequency from that
  • You are using a counter/timer with 16 bit. This fits to ~65536 ticks are 1s (1 Hz) and so on

My proposal for you is to switch to a 32-bit timer so you can measure longer periods without timer overrun and have a higher tick freq.

Traveo2 has both 16 and 32 bit TCPWM. To find out the timers with 32-bit resolution please check the datasheet, chapter Peripheral I/O-map. Here is an example:

Ralf_0-1641369187920.png

Best regards

Ralf