AIM CAN Channel mapping

Discussions on CAN mapping for ECUs, sensors, PDMs, and more.
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rex-racer
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Joined: Mon Jun 12, 2017 9:35 pm

AIM CAN Channel mapping

Post by rex-racer »

I know this isn't the AIM support forum but I was wondering if anyone has had a chance to use AIMs CAN output feature.

I know there is a LUA script to read the SmartyCam CAN channel but I would prefer to direct Map the can channel. I asked AIM support how to access this on the ECU CAN (as opposed to the SmartyCam CAN) and their reply was why not use the CAN output feature. Unfortunately , there doesn't seem to be any documentation on how to use this feature. It's not clear if you just arbitrarily pick a channel ID and bit and make up your own stuff or does one need to mimic the CAN 1 stream on CAN 2.

Anyone play with this at all? I would like to be able to direct MAP all data and if I can output the ECU data on CAN bus 2 since there's not a lot going on there, this would keep things nice and clean.
A Race Car exists in 2 states: Broken or in the process of becoming that way.

MikeD
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Post by MikeD »

Hi rex-racer,
I wrote a config for a customer by using the AIM CAN output feature...
You do NOT need to mimic any dedicated stream but can choose ID's and position of bytes+bits on your own.
Obviously you have to make sure that you do not choose any ID's that are already being broadcasted or used in whatever way by the CAN network where you output AIM channels.

There was just one parameter out of about 15 that I could not receive correctly by the RCP and that was the gear output from AIM... because I created the whole config remotely away from the car I was not able to nail down the problem until now...
Anyway all the other parameters were streamed and received successfully as intended.
Good luck!

rex-racer
Posts: 18
Joined: Mon Jun 12, 2017 9:35 pm

Post by rex-racer »

Excellent!! That's what I was hoping to hear.

For the ID, where does this typically start? 1000 and then +1 from there for each channel? Does the channel ID need to be in hex or can it be in dec? I have the Izze tire temps sensors and he starts his at 1200. Just not sure how arbitrary this address is or what the typical traditional starting place is.

Thanks
Jay
A Race Car exists in 2 states: Broken or in the process of becoming that way.

MikeD
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Location: Austria
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Post by MikeD »

Within AIM RS3 you define CAN ID's in hex format (this is clearly visible when you look at the software).

Lower CAN ID's have higher priority in case of two different messages being sent at the exact same moment, so the lower IDs will be sent before the higher IDs to avoid collisions on the network... anyway we are talking about a millisecond delay in such cases, so not a problem when you are just looking for datalogging... more important to choose correct IDs for time sensitive/safety critical functions.
I configured most AIM output parameters to use 2 bytes which equals 4 parameters per message.

Will guide you through the rest of the process via mail...

brentp
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Post by brentp »

Thanks for posting, and yes - this is the correct forum for AIM CAN integration - it covers all CAN integration.

The goal for the direct CAN mapping is to move away from needing Lua scripting, and the AIM integration should work especially well. Ultimately we will have direct CAN mapping pre-sets for AIM as well, which will make integration easier.

Thanks MikeD for the help too!
Brent Picasso
CEO and Founder, Autosport Labs
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rex-racer
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Joined: Mon Jun 12, 2017 9:35 pm

Post by rex-racer »

So after reading that bit of info (felt a bit dumb about the address when I opened RS3 and the "hex" is right there...duh). I started playing with the CAN output function and got it to work along with the Izze tire temp sensors through the AIM CAN2 bus as well (had to do a hard power reset for everything to work). The temps take a formula to convert the raw data to actual temp readings but after a while of playing with it I seem to have temps and pressures along with RPM data. The rest of the data seems to pop in pretty nice.

I just re-read the APEX RC data sheet and noticed direct CAN mapping is limited to 30 channels. Those temp sensors chew up channels at a pretty good rate. Is this a hardware or software limitation?
A Race Car exists in 2 states: Broken or in the process of becoming that way.

brentp
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Post by brentp »

Great, thanks for the update.

Good news, you can map up to 100 channels now with the latest firmware: https://www.autosportlabs.com/racecaptu ... -released/
Brent Picasso
CEO and Founder, Autosport Labs
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