Reading exhaust temps through can bus from arduino

[Angelo/E30M3-M50B28T-E36+]

Hi guys,

I setup9 temp sensors reading exhaust, gearbox, diff... And i want to send this data to the link ecu through can bus i already got the can bus shield for arduino, also if there any other way to read them in the link ecu and log those values i am welcoming suggestions as wwellanything other then canbus

 

Has anyone done this before that can shed some light on it?

 

Kind regards

[neil brown]

What ecu ? 
 

 

[Angelo/E30M3-M50B28T-E36+]

E36+ PNP

[Adamw]

Assuming it is a G4+, not an older G4 (your post is in the G4 section), then below is the list of inputs that can be received as CAN bus messages.  You will notice there are 8 "CAN TC Cyl%#", these are what you would usually use for the EGTs, there is no gearbox or diff temp in this list but you could use CAN TC Cyl 7 & 8 for these (so they are logged/displayed as "°C"), or you could use the "CAN AN V" channels but these are only displayed with "Volts" units.

Or you have two spare temp inputs on the expansion connector so you could wire the gearbox/diff temp directly to the ECU (would then be labeled more correctly and have correct units).

 

[Angelo/E30M3-M50B28T-E36+]

Hi adam yes i posted to g4 by mistake i am using a e36+ pnp i dont see the can tc in the ecu settings but still the ecu has two can ports and i am trying to send 9 temp values through can bus from an arduino to the ecu how does those can tc have any parameter or specific can adress or id?

[Adamw]

The Link CAN is very flexible, you can use any ID you like, 29bit or 11bit, any common bit rate and the message can be formatted however you like.  

Most commonly with commercially available EGT amps they send each EGT channel as 2 bytes.  This means you can fit 4 channels per CAN frame.  Depending on the resolution you want another option would be to multply the values by 5 and send as a single byte - then you fit 8 channels in one frame.  EGT would then move in steps of 5deg but thats probably as accurate as it needs to be.  

Note the CAN setup in Link uses decimal rather than hex for the ID.  So for instance a device with ID 0x3E8 (hex) would be set up in Link as ID 1000.

 

Below is as example for 4 EGT's coming in on ID1552 (610hex), 2bytes, Intel or LSB:

 

You can then use the EGT's in the ECU however you like.  You can just log them, you can send them to a dash or display on a dash page in PC link, or you can set up a limiter or a fuel trim, ign trim, boost trim, warning light, etc if say any cyl goes above a certain value, you can use them on the axis of almost any table or conditions for auxes etc...

[Angelo/E30M3-M50B28T-E36+]

I got it working yesterday used all 8 can tc on can1 and connected obd2 on can2 but one thing i didn't get is that can tc can only count to 255 after 255 it starts from 0 again how can i make it count to 900 or a 1000?

 

Also tried can digital i put but i have no idea what does the digital input read? Cz i tried to send it true false and high low and 1/0 but couldn't get it to turn on? Any idea what does it read to turn on and off?

[Adamw]

2 hours ago, Angelo/E30M3-M50B28T-E36+ said:

but one thing i didn't get is that can tc can only count to 255 after 255 it starts from 0 again

Sounds like you are either only looking at 1 byte or your endianess is set wrong.  The CAN TC parameter is capable of reading up to 10000°C.

 

2 hours ago, Angelo/E30M3-M50B28T-E36+ said:

Also tried can digital i put but i have no idea what does the digital input read? Cz i tried to send it true false and high low and 1/0 but couldn't get it to turn on? Any idea what does it read to turn on and off?

You can use the test calculator tab of the CAN setup screen to see how any parameter works.  For a CAN DI it is as you assumed, 0 = off, 1 = On.