# Wheel speed sensors on the CANBUS?



## remy_martian (Feb 4, 2019)

You could just use your phone to show speed using GPS


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## Scotty274 (Jul 1, 2020)

remy_martian said:


> You could just use your phone to show speed using GPS


Unfortunately I can't if I want it road legal


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## oudevolvo (Mar 10, 2015)

My guess would be that the hub sensors just output some kind of frequency signal and that there is a controller that reads these and sends them onto the CAN-bus.
CAN-bus sensors are possible but I think these would be relatively expensive.
Is there a wiring diagram available for the eNV200?

I’m working on a “Mechanical Speedo Driver” that can take it’s onboard GPS, a pulse or CAN message as input for driving a speedo cable.

__
http://instagr.am/p/CGzHK14o_4M/
Would that help?


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## kennybobby (Aug 10, 2012)

CAN buss messages are sent with ID fields and data fields--it is not likely that the direct sensor signal is put on the CAN buss. Not sure where you got that idea?


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## Dala (Jan 10, 2018)

I have decoded most of the passive LEAF CAN communication, results can be found here: dalathegreat/leaf_can_bus_messages

To answer your question, No, you wont be getting wheelspeed that way. The ABS module handles the conversion, and spits out a 0x284 message containing the pulses.

I suggest you mount a tablet, and run Leafspy on 50% of the screen, and a GPS speedometer on the other 50% of the screen. This will make it roadlegal (atleast in Finland)

EDIT: I just saw your other thread that you couldn't do GPS based speed. Then I suggest using the motor RPM, which is available on CAN. And scale this information to km/h .


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## Scotty274 (Jul 1, 2020)

kennybobby said:


> CAN buss messages are sent with ID fields and data fields--it is not likely that the direct sensor signal is put on the CAN buss. Not sure where you got that idea?


Nissan dealer was the one that told me that, said that's why the hubs are so expensive was because of CANBUS sensors in them.


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## Scotty274 (Jul 1, 2020)

Dala said:


> I have decoded most of the passive LEAF CAN communication, results can be found here: dalathegreat/leaf_can_bus_messages
> 
> To answer your question, No, you wont be getting wheelspeed that way. The ABS module handles the conversion, and spits out a 0x284 message containing the pulses.
> 
> ...


Do you think the ABS module would be easy to bring across? Or is that reliant on a heap of other stuff as well?


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## brian_ (Feb 7, 2017)

Scotty274 said:


> Nissan dealer was the one that told me that, said that's why the hubs are so expensive was because of CANBUS sensors in them.


Unfortunately, this confirms that automotive dealerships are essentially useless as a source of technical information. Service departments mostly read codes and swap components, with little understanding of what is inside those components.


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## brian_ (Feb 7, 2017)

Scotty274 said:


> ... Now from what I can gather they just plop their readouts onto the CANBUS and leave it there. Whatever needs it, grabs it and reads it.
> ...
> So to me, if it's just reading what's on the CANBUS, just dumping the Wheel Speed sensors into the CANBUS, then that should give me speed readouts? Yes?





kennybobby said:


> CAN buss messages are sent with ID fields and data fields--it is not likely that the direct sensor signal is put on the CAN buss.


Yes, of course CAN messages are structures with ID and data fields, but LeafSpy handles that. I think the question was really whether the CAN messages from the sensors were all that is needed, and the answer appears to be that the CAN messages are generated by the ABS controller (not directly by the wheel speed sensors), but yes, with that controller any suitaby configurable CAN device can read those and scale them to a value for display as speed.

I'm not surprised that the ABS controller gets raw pulses from the wheel speed sensors rather than using CAN communication, since it needs rapid response and this way it doesn't need to wait for the data publishing cycle.

I agree that the motor speed is a more suitable source, since anything will need scaling.


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