[ESDave]

Thought i would put this up here for anyone interested, also if there is anything i could have done better or other features i don't know about keen to find out!!

The speeduino does not use all the analog inputs on the Arduino. On the MX5 PNP A8 is extra handy as it is already connected to the clamping protection IC:



I want to add a coolant pressure sensor to log in my car. Have purchased a few of these sensors:

https://www.ebay.com/itm/Pressure-trans ... SwxBdZgiGA

3 wire sensor - so needs a 5V supply and has the following transfer curve:



So a small mod to the PCB to get 5V - a series 2.2k resistor for the signal and ground. I added a new connector at the back, just prefer not to try and stuff new lines into the OEM connectors.



Then in tuner studio "Accessories" -> "Local Auxillary Input Channel Configuration" set the source appropriately:



Then in "Tools" -> "Custom Channel Editor" add details for the sensor:



Then add a datalog variable:



And voila - you now have a sensor input you can log with correct scale and units!!!

Testing the sensor on a fixture:





So good!!!

[dazq]

Fantastic work !
Maybe you would consider writing a how to that we can add into the wiki?
If you don't have wiki access just post the files and txt here and one of us will add it to the appropriate section.

[noisymime]

Great write up!

Just as a further piece of advice, if you add a cap or two on the signal line, you'll really smooth the signal out a little. I usually use a 0.1uF and 0.22uF cap on all the analog inputs.

[Mr_Hypnotic]

Wow! Thank you ESDave! That is a great write up.

[ESDave]

Thanks for the feedback on the decoupling / filter capacitor - should definitely be included!

Happy to make a write up for the wiki - how do i get access? I have some other things that might be helpful to add like an MX5 fuel pump wiring schematic that shows how the speeduino works within the factory wiring etc...

[dazq]

ESdave just ask noisymime , he can set you up with access to the wiki.

[Black Knight]

One more for well done.

This is what we all need.

I have a new knock sensor controller working now and just got the axillary input working but it seemed a bit unresponsive. Slow and delay.
I think your write up gave me the answer.

I did not know about the custom channel editor page. That is what I was missing.
Setting limits and inc file control.

I have a good clean square wave signal of 4.5 vdc square for every knock signal as my input for knock. I can hear and see a pin drop if I want to as well as set it to see only see onset knock.

Sorry for introducing what I am doing on your thread but I may need some help setting it up as I am square wave and may need advice as how to get a setup that has as little delay as possible.

This new info here for custom channel wizard should be the part that makes this knock sensor controller work as it should.

I can't wait to try the wizard out.

Thanks again to all for this input.

Black Knight

[pazi88]

The aux in channels are only read in 4Hz pace. So really slow for any kind of knock detection. To actually detect that at the moment it happens, you need to have the knock signal to be detected with interrupt.

Good news, is that the whole knock control is already there in speeduino. You can enable it in TS by removing the ; from this line in speeduino.ini:

Code: Select all

  ;subMenu = knockSettings,          "Knock Settings"

Bad news is that I have no idea if any of that works. It's commented out for a reason and I don't know what is the reason.

knock.png (37.62 KiB) Viewed 11536 times

[Black Knight]

The aux in channels are only read in 4Hz pace. So really slow for any kind of knock detection. To actually detect that at the moment it happens, you need to have the knock signal to be detected with interrupt.

Good news, is that the whole knock control is already there in speeduino. You can enable it in TS by removing the ; from this line in speeduino.ini:

Code: Select all

  ;subMenu = knockSettings,          "Knock Settings"

Bad news is that I have no idea if any of that works. It's commented out for a reason and I don't know what is the reason.
knock.png

Thanks for that.

I knew it was there but now I need to learn how to use it for my set up.
I think it is not set up yet as it will need a circuit controller to work with it.
Mine might work??????

I have it working now with only my controller and aux input set up.
No firmware is part of it for now.
I do have a signal lag of about 25 ms. on the TS logger. I was at 250ms delay before.
Progress and more to come.
Small changes to my controller and inc file are helping here and that is due to finding aux input and the help here.
Got sharp clean fast signals today. I could even see/hear a pencil eraser with my bench test setup.
I can then dial out these signals and see/hear only onset knock.

I have only been learning aux in for two days, so I have more to learn.
It work so well.

I have been working on this knock sensor set up for 5 weeks as a hobby and it is working quite well.

I hope to be posting the out come soon and the try the knock control window posted above.

Very cool.

Thanks again.

Black Knight

[Black Knight]

The aux in channels are only read in 4Hz pace. So really slow for any kind of knock detection. To actually detect that at the moment it happens, you need to have the knock signal to be detected with interrupt.

Good news, is that the whole knock control is already there in speeduino. You can enable it in TS by removing the ; from this line in speeduino.ini:

Code: Select all

  ;subMenu = knockSettings,          "Knock Settings"

Bad news is that I have no idea if any of that works. It's commented out for a reason and I don't know what is the reason.
knock.png

Pazi88

I am having good progress with all of this but have a question.

In regards to the 4hz limit.

Can you tell me how it is limited to 4hz.

Arduino is using 10hz.
I worked with TS and they say TS is not limiting the hz.
That leaves only the firmware regulating it or my controller.

If it is the firmware, is there a way to change the limits of aux input?

I ran a dual signal from my knock controller. One to TPS and one to aux input and found them to be similar for response time. Mine is a tapered square wave on TS logging and TPS is saw tooth.
There is some minor differences but mostly the same. I also did this with IAT and got similar results.
I also ran the signal in to the crank signal input, and yes, that was very good. The best.

It has not been easy to get the aux input to work this fast but it is getting very close with controller settings and calibration set up.

I do not mean to challenge your input, I only wish to understand it more.

I am new to this aux input so forgive my limited use of some terms.

Thanks again for your help.

Black Knight