Updated CAN Protocol for AIM MXS (with all analogs and Lambda)

K-Series Programmable ECU installation questions / support issues
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thomasn
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Joined: Thu Aug 30, 2018 1:33 am

Updated CAN Protocol for AIM MXS (with all analogs and Lambda)

Post by thomasn » Tue Oct 08, 2019 10:04 am

Hi,

since i got lot of PM/emails asking for my custom AIM MXS CAN protocol for the KPRO V4, here is my version and documentation :

The Kpro can protocol included in the AIM library has some limitations :

- only 2 analog inputs returned, for specific sensors (not documented)
- no lambda value returned

So i developed a custom to read that.

First, you have to set-up the kpro board for the protocol to be used : Motec SDL/ADL
param-kpro.PNG
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Then, you have to set-up the AIM Race studio software, download and install the protocol attached to this message.
HONDATA_KPRO4_DEV_@20190507_092544_009877.xc1.zip
(58.42 KiB) Downloaded 8 times
Then, when you create a new configuration for a MXS, you choose the new protocol, and you have the following channels available :
channels1.PNG
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channels2.PNG
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All the analog channels are returned as raw millivolts values : you need to create a Math channel for each sensor to make it human readable,

for example, for a 0-10bar oil/fuel pressure sensor like this one : https://www.reveltronics.com/en/shop/60 ... -5v-detail

I had to set the following values :
example-math.PNG
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I will not help you to create those math channels or to wire your sensors that requires pull-up resistors, you need to make your own calculations for this.
I you installed a kpro, a AIM dash, then you should be able to do a little maths !


If you do all this steps properly, you should be able to display some very interesting data : i have Lambda, EGT, Oil T°, Oil Pressure, fuel pressure, ... on my dash (when i want to confirm that everything is working as it should on track)
Thanks.

thomasn
Posts: 16
Joined: Thu Aug 30, 2018 1:33 am

Re: Updated CAN Protocol for AIM MXS (with all analogs and Lambda)

Post by thomasn » Tue Oct 08, 2019 10:10 am

Example of display with this protocol :
IMG_1679.PNG
IMG_1679.PNG (3.24 MiB) Viewed 301 times

thomasn
Posts: 16
Joined: Thu Aug 30, 2018 1:33 am

Re: Updated CAN Protocol for AIM MXS (with all analogs and Lambda)

Post by thomasn » Wed Oct 09, 2019 3:21 am

Example of adding a custom temperature sensor on a Kpro, how to wire it, how to create the Kpro custom input, and the math channel for the AIM :

1) EGT sensor :

EGT sensors are for most of them k-type sensors, that requires amplifications to be read. I choose to use a RTD sensor supplied by AEM (AEM 30-2050), that you can read directly.

The data sheet is here : https://www.aemelectronics.com/files/in ... %20Kit.pdf

We need to use a pull-up resistor to wire it to our K-pro (please read the documentation to understand : https://www.hondata.com/help/kmanager/i ... rature.htm

So, you open your favorite spreadsheet application, and you begin your calculations :
Screenshot 2019-10-09 at 12.07.15.png
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First, i typed the data sheet values : Column A = temperature, column B = sensor resistance

Secondly, i choose a resistor value that will allow me to have a good range on the reading, in my case, 680ohm is fine, and is a classical resistor value.

Then, i calculate the Voltage that the kpro will read with the sensor resistance + pull-up resistor for each sensor temperature in the datasheet.

For a temperature of 800°c, the Voltage is :

(5v * 738ohm) / (738ohm + 680ohm) = 2.6022v

Where :

5v is the supply voltage we use (taken on E5 on E connector)
738ohm is the resistance of the sensor at 800°c
680ohm is the resistance of the pull-up resistor

Then, i choose the range of temperature i want to be accurate in : for an EGT, i want to read the 600-1000°C range, no need to be accurate out of this range.

And magic : on this range, the curve is almost flat : our reading is almost linear then.

For the Kpro, we insert the values in the settings of the analog input :
EGT-kpro.PNG
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For the AIM, you need a bit more maths :

Then, you find your Y=AX+B values (remember that math lesson at school).

Y is your voltage read by the Kpro,
X is the actual temperature

A is the multiplier and B the offset.

Be careful for the AIM : the voltage reading is not in volts but millivolts. And you need to reverse Y and X since you want to get the temperature from a voltage and not a voltage from a temperature
egt-zim.PNG
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thomasn
Posts: 16
Joined: Thu Aug 30, 2018 1:33 am

Re: Updated CAN Protocol for AIM MXS (with all analogs and Lambda)

Post by thomasn » Wed Oct 09, 2019 3:24 am

Another example with the AEM 30-2012 sensor :
Screenshot 2019-10-09 at 12.23.05.png
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aem302012.PNG
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thomasn
Posts: 16
Joined: Thu Aug 30, 2018 1:33 am

Re: Updated CAN Protocol for AIM MXS (with all analogs and Lambda)

Post by thomasn » Wed Oct 09, 2019 3:30 am

Also, i got some questions about the fact that the Ethanol content and Fuel temperature is not included in my protocol :

i can add them but i may ask a little contribution on the time spent for this, and if you want more help on how to install other custom sensors if you're not able to calculate the pull-up resistor / values to set in kpro manager / AIM race studio.

If you want, send me a PM and we can discuss pricing (not a lot of course ;) )

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Hondata
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Re: Updated CAN Protocol for AIM MXS (with all analogs and Lambda)

Post by Hondata » Sun Oct 13, 2019 5:39 pm

I'm not sure if your external conversions use Steinhart-Hart for the temps or an approximation.

I don't see a problem adding the ethanol to the AiM output as existing setups will just ignore the extra CAN packet, so I can do that if you would like.
Hondata

thomasn
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Re: Updated CAN Protocol for AIM MXS (with all analogs and Lambda)

Post by thomasn » Tue Oct 22, 2019 9:13 am

I use approximations over a specific range that i choose, no Steinhart-Hart.

Ethanol/Fuel temp is already included in your Motec SDL/ADL protocol that i used (i wanted the 8 analog inputs, and the AIM can protocol has only 4 analogs inputs), but not included in the AIM reading protocol i developed to read the Motec SDL/ADL sent by the kpro.

thomasn
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Re: Updated CAN Protocol for AIM MXS (with all analogs and Lambda)

Post by thomasn » Tue Oct 22, 2019 9:15 am

Is it possible to include "Mil status" in the protocols ?

that would be great since i have only a CAN interface between the dashboard and kpro board

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Hondata
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Re: Updated CAN Protocol for AIM MXS (with all analogs and Lambda)

Post by Hondata » Tue Oct 22, 2019 2:36 pm

Yes, added MIL. Anything else?
Hondata

thomasn
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Re: Updated CAN Protocol for AIM MXS (with all analogs and Lambda)

Post by thomasn » Wed Oct 23, 2019 3:25 am

If possible :

VTEC status,
open/closed loop status

For external datalogging purpose that could be awesome !

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