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Need help configuring AV input please

PostPosted: Mon Feb 05, 2018 1:33 pm
by FoxSTI
hi guys, Its been a while.
I have this video to show what I have done do far maybe someone can tell me if I am on the right track of totally lost.

Basically I want to input 4 different voltage into one analog ping and have the dash display a message depending on the voltage.

Resting voltage is 5v.
V#1 = 0
V#2 = 1.8
V#3 = 3.3

I am using an User channel with a calibration if absolute voltage that looks like:
0 - 0
1.8 - 1.8
3.3 - 3.3
5 - 5

https://photos.app.goo.gl/REa5irnn2dzokURu1

Thank you in advance.

Re: Need help configuring AV input please

PostPosted: Tue Feb 06, 2018 11:21 am
by FoxSTI
Hi folks,
Never mind the video, I got most of it to work.
In display creator used the channel I created from the table. however I need some help to fine tune things.

The physical knob is non latching, meaning it will go back up to 5v as soon I stop actuating it. However the car will retain the last setting. What I want if for my DASH to log this value and display it. Therefore I would like to know if there a way to have the channel value remain either V#1 = 0 V#2 = 1.8, V#3 = 3.3

The problem I am running into is that while I measured the voltages they seem to vary slightly so the display of the channel is not consistent.

Can someone please offer some guidance?
Thank you

Re: Need help configuring AV input please

PostPosted: Tue Feb 06, 2018 1:00 pm
by David Ferguson
It sounds like you have the wrong kind of multi-position switch if it doesn't stay in the last setting.

However, assuming you aren't going to change it... Determining the current position isn't too difficult, you setup a 2D table where a range of voltage produce the same output. I chose a range of +/- 0.2v to create something like this:

2D descrete table.JPG
2D descrete table.JPG (42.31 KiB) Viewed 8124 times


However, this will produce an output of 0 for values not in the table, I think that you would just then create alarms that only display when the value is true for some small period of time (i.e. the condition was "GP 1 > 0 for 0.2 sec"), that should avoid messages while you move the knob to the desired position.

If you log the data, you will always end up with the value being zero (since it returns to 5V), but you should be able to quickly look through the data to find the last valid value. If you had I2 Pro, you could create a math channel that would do that for you, but it's not possible in the C125 dash.

Re: Need help configuring AV input please

PostPosted: Tue Feb 06, 2018 2:07 pm
by FoxSTI
Thanks Dave, yeah the switch in an OEM Switch wired to the car so I cant change it and I am not sure why they made it that way. I ideally I should be tracing the signal coming out of the ECU.

I had thought if your solution, glad you suggested it.
Just to double check, the hysteresis values means essentually + or - / give or take ?

Seems like the C125 is pretty limited when you start to get fancy. I will have to update in the future.

Re: Need help configuring AV input please

PostPosted: Sun Feb 11, 2018 4:04 am
by Scott@FP
Use a 'make before break' style switch so the voltage values don't bounce toward fault areas near 0v and 5v as the contacts go open between switch positions.