CAN questions (was: MS3 pre-1.4 alpha 8 released)

[Alfagta]

Did the PDF document not explain it clearly enough?

James

It's a Little bit confusing because the structure of the Megasquirt Can Protocol is not Standard.
But i'm working on it to implement the Handshake....

[jsmcortina]

Did the PDF document not explain it clearly enough?

James

It's a Little bit confusing because the structure of the Megasquirt Can Protocol is not Standard.

Well, yes, that was the reason for writing the PDF.

James

[Alfagta]

Did the PDF document not explain it clearly enough?

James

It's a Little bit confusing because the structure of the Megasquirt Can Protocol is not Standard.

Well, yes, that was the reason for writing the PDF.

James

It woul'd be helpful ift there were a few Examples of Communication packages...

[Alfagta]

Hello James,

today i've tried CAN VSS.
How does megasquirt expect the CAN VSS data?

[jsmcortina]

Hello James,

today i've tried CAN VSS.
How does megasquirt expect the CAN VSS data?

In what way? Units? Address?

Internally units of ms^-1 * 10 are used.
i.e. 23 units = 2.3 ms^-1

James

[Alfagta]

I mein what Format the MS expect.

And is there a case where the MS pool all VSS data with 1 Frame?
Or will the MS only pool one VSS Data at a time?

[jsmcortina]

Presently there is one request message per VSS channel. I do have some future ideas to make this more efficient.

James

[Alfagta]

Okay,

yes that would be easier.
The MS can poll all 4 with one request.
And when e.g. VSS3 and 4 or what ever isn't active the MS can override these data...
And with 16Bit it would be possible with 1 request.

[Alfagta]

Hello James,

today i've tried CAN VSS.
How does megasquirt expect the CAN VSS data?

In what way? Units? Address?

Internally units of ms^-1 * 10 are used.
i.e. 23 units = 2.3 ms^-1

James

Are you sure James?
When i send 0x17 to the MS i read 83 KPH at the gauge.

And do you have any future idea for a timeout for CAN Poll?
Or any other surveillance for all the CAN receivings?

[jsmcortina]

Ah, you also need to set the scaling factor on the VSS page.

James

[Alfagta]

Ah, you also need to set the scaling factor on the VSS page.

James

Okay, now with 100% scaling it Looks good.
1 Digit ^ 0.36 KPH...
Thanks again James

[jsmcortina]

I added a couple of CAN transmission examples to the protocol PDF.

James

[Alfagta]

I added a couple of CAN transmission examples to the protocol PDF.

James

Hello James,

thanks for that this would new users help to learn more about the can communication.

I think there is a small fault in Point 4.2 outbound request my varblk = 6 is in the doc but i think it should be my varblk = 7...

Best Regards