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KproV4 Analog inputs

Posted: Mon Mar 04, 2024 8:52 am
by sloth4urluv
I have a few questions about the analog inputs on the KproV4.

First question is about the sample rate of the analog inputs.
I have a 30-2130-150 150psi pressure sensor monitoring the oil pressure (teed off of the supercharger oil feed).
At idle it fluctuates around 2psi and when driving at a constant RPM it fluctuates around 20psi.
From the datalogs I have (recorded on laptop using a USB connection) I see they are being recorded at around 20Hz.
My question is how fast are they sampled on the Kpro, and does the Kpro have any analog antialiasing filters with the analog inputs?

Currently I am not applying any digital filtering to the signal as I am wondering if I need to add a restrictor inline with the sensor or add an RC lowpass filter inline with the analog input. From the limited datarate that I can record with the laptop the signal appears to be aliasing as while driving at a fairly constant RPM I see around a 1.1Hz sinewave @2647RPM and 4.1Hz@2711RPM.
If it is aliasing the digital filtering will help some, but it is impossible for it to filter out the higher frequency components in higher Nyquist zones that alias down to lower frequencies.
S2000-Oil_Pressure.png
My second question is about the analog outputs and the Hondata mobile app.
I can obviously see the analog inputs through Kmanager, but even though I can select the analog inputs to be displayed on the mobile app they are greyed out as if they are not being broadcast over bluetooth.
Is there a way to monitor those inputs in the mobile app?

Re: KproV4 Analog inputs

Posted: Tue Mar 05, 2024 9:58 am
by Hondata
The analog inputs are sampled at 100 Hz. They are also stored at 100 Hz for on board datalogging, with USB datalogging the rate is more dependent on the USB so will be less.

There is a smoothing function in KManager which operates on the KPro at time of sample.

The analog values are not broadcast on bluetooth.

The root cause is that the oil pressure has a lot of fluctuation due to the oil pump. Add a length of braided hose between the sample point and sensor often helps a lot.

Re: KproV4 Analog inputs

Posted: Tue Mar 05, 2024 12:29 pm
by sloth4urluv
Thanks for the info.

Any chance the analog inputs could ever be broadcasted over bluetooth in the future?

I'll try adding something like a 45Hz low pass filter to the input or restrictor in series with the sensor to see if it cleans it up.