Noisy Interrupt using CC Channel at 81-83 Hz and 241 - 243 Hz.

RE: Noisy Interrupt using CC Channel at 81-83 Hz and 241 - 243 Hz.

inspiringdev123 — Fri, 07 Jul 2023 16:24:56 GMT

Timer was being stopped right on the overflow value with these frequencies causing it to be one whole timer period higher at times. Just needed to pause and clear the timer on the interrupt to avoid this anomaly.

RE: Noisy Interrupt using CC Channel at 81-83 Hz and 241 - 243 Hz.

Sigurd — Fri, 07 Jul 2023 16:20:03 GMT

Hi,

I haven't tested your implementation, but you might want to have a look at the examples posted in this post here: RE: PPI Configuration to Count Pulses , and compare that to your own implementation.

RE: Noisy Interrupt using CC Channel at 81-83 Hz and 241 - 243 Hz.

inspiringdev123 — Tue, 27 Jun 2023 13:51:52 GMT

It goes through a low pass filter and is going into the nrf in the range from 0-3.3 V DC. Sorry, thought you were referring to the source

RE: Noisy Interrupt using CC Channel at 81-83 Hz and 241 - 243 Hz.

Sigurd — Tue, 27 Jun 2023 13:48:02 GMT

You are inputting this square wave to the nRF52832, right? Are you using some logic level switches? You can't use these voltages directly on the nRF52832. See I/O pin voltage: https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/abs_max_ratings.html?cp=5_2_0_4#abs_max_ratings

RE: Noisy Interrupt using CC Channel at 81-83 Hz and 241 - 243 Hz.

inspiringdev123 — Tue, 27 Jun 2023 13:36:29 GMT

High is 7.5. Low is -2.5.

RE: Noisy Interrupt using CC Channel at 81-83 Hz and 241 - 243 Hz.

Sigurd — Tue, 27 Jun 2023 09:23:03 GMT

[quote user="inspiringdev123"]VDD of the wave is 10 Vpp with a 2.5 V offset.[/quote]

So high= 3.5V , and low is 1.5V?

RE: Noisy Interrupt using CC Channel at 81-83 Hz and 241 - 243 Hz.

inspiringdev123 — Fri, 23 Jun 2023 15:12:10 GMT

VDD is at 3.58 V. I scoped it and the square wave signal is consistent with what it should be. No anomalies detected. VDD of the wave is 10 Vpp with a 2.5 V offset.

RE: Noisy Interrupt using CC Channel at 81-83 Hz and 241 - 243 Hz.

Sigurd — Fri, 23 Jun 2023 09:30:52 GMT

Hi,

That sounds strange. What is VDD(supply voltage) used on the nRF52832 device? Do you have a scope image of the square wave signal for when this is happens? What is VDD of the square wave signal?

RE: Noisy Interrupt using CC Channel at 81-83 Hz and 241 - 243 Hz.

inspiringdev123 — Thu, 22 Jun 2023 13:37:22 GMT

Yeah so I am sending a square wave from a function generator to a GPIO pin to cause an interrupt to stop the timer count and convert it to MPH or RPM depending on certain attributes. It works smoothly with all frequencies except the ones posted. It seems like the interrupt does not trigger as expected during those frequencies.

RE: Noisy Interrupt using CC Channel at 81-83 Hz and 241 - 243 Hz.

Sigurd — Thu, 22 Jun 2023 12:31:59 GMT

Hi,

Could you explain a bit more what you mean by "Noisy Interrupt" ?