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sama

Help with can setup

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Hi everybody, sorry I didn't provide serial number but I don't have the number near, I will edit such information tomorrow. i have just installed a G4+ on a Toyota Celica built for circuit racing and the car has the Bosch Motorsports ABS system which has the ability to share some information via CAN, I need to setup the 4 wheel speed to be able to start playing with the both the boost by speed and at the same time with traction control, I got some help with the people over at Bosch and got this information, I will be trying to set it up tomorrow, but they ask me something that I don't have a clue as this is my first time setting up a Link ecu. 

This is what I got: 

Stream 1 -> single frame only:

            "add parameters" for a total of four parameters:

 

            Parameter = LF Wheel Speed

            Start position = 0

            Width = 16

            Byte order = LS First

            Type = Unsigned

            Multiplier = 45

            Divider = 8

            Offset = 0

 

            Parameter = RF Wheel Speed

            Start position = 16

            width/byte/type/multiplier/divider/offset = same as above

 

            Parameter = LR Wheel Speed

            Start position = 32

            width/byte/type/multiplier/divider/offset = same as above

 

            Parameter = RR Wheel Speed

            Start position = 48

            width/byte/type/multiplier/divider/offset = same as above

 

If you have a problem with the units translating incorrectly, it's most likely because of the multiplier and divider.  I don't know what the Link ECU uses for units - m/s, km/h, km/min, etc...  You might have to check with Link for the unit translation.

 Thanks all for your help!


Sama

 

 

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Hi Sama,

According to the info Bosch sent you the Frame should be set up to look like this:

bosch_streams.thumb.PNG.43aaa6f2cd77a487

You will also need to know which CAN module of the Link ECU you have wired up to the CAN bus, the Bit Rate the bus runs at, the CAN ID Format, and the CAN ID that the Bosch ABS module is sending the data on.

bosch_Mode.thumb.PNG.bb1d9c4c220a9f4b84f

Scott

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Thanks Scott, would this provide a value in kmh? on my G4+ I have just seen CAN2 on the can module window so I assume there should be no issue. 

I had received this info prior to the one I shared before: 

 

The ECU needs to be able to receive information on CAN, and it needs to be programmable to where you can enter the following:

ID: 0x560h or 1376

Length:16 bit

Offset: 0

Factor: 0.015625 m/s per bit

Range: 0..100m/s

Unsigned, Intel / LSB / little endian alignment

 

 

Your ABS unit is 500kbps CAN rate.  Your ECU will need to be configured to match this bus speed.

 

So that should fill everything up correctly

 

 

 

 

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Hi Sama,

Great, that is the info you need. The 'Format' will be normal.

The multiplier and divider settings will control the scaling of the data to the CAN bus number. As the person from Bosch mentioned, these may need some adjustment to make tings read correct in the desired units (km/h?). Here is how the two different devices work:

ABS                         CAN Bus value        ECU

0.000000 m/s            0                             0.0 km/h  (0 m/s)

0.015625 m/s            1                             0.1 km/h  (0.027778 m/s)

0.031250 m/s            2                             0.2 km/h  (0.055556 m/s)

 

So 0.015625 = 0.027778x   ->  x = 0.5625. This is the multiplier you need to convert from the steps the ABS uses to the steps the ECU needs. However the Multiplier and Divider fields in the ECU can only accept whole numbers, so you will need:

Multiplier = 9

Divider = 16

The other settings from above should be the same. 

Scott.

 

Edited by Scott
Mistake in my math

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How did you get on with the traction control sama? I have the Bosch Motorsport ABS also and am looking into feeding the wheel speed sensors into the link over can bus.

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