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

[Alfagta]

Hello,

i have a Setting error and don't know how to handle this one...
Can anyone help?

Config error.JPG

[jsmcortina]

Looks like your CAN transceiver is broken.

James

[Alfagta]

How does the MS can check this?
This Error is coming up when i try to send Can data to the MS.

Broadcasting with the MS is working normally.

[jsmcortina]

If the CAN system fails to initialise within a reasonable period of time, the code decides that it must be broken and flags that error.

Code: Select all

    /* wait for synch to bus */
    ix = 0;
    while ((!(CAN0CTL0 & 0x10)) && (ix < 0xfffe)) {
        ix++;
        asm("nop");
        asm("nop");
        asm("nop");
        asm("nop");
    }
    if (ix == 0xfffe) { // normal behaviour ~38
        // CAN broken
        conf_err = 190;
    }

The only times I've seen it are when a customer has damaged the MS3 card and broken the processor. Sometimes the CAN chip gets broken too.

James

[Alfagta]

Ah okay,
I think mine is okay because Broadcasting work without any error.
The only Problem is that i receive strange data.
I'm trying to figure out why i get this Data.I think the Problem is my test System.
However it's not possible for me to send Data to the MS.

[Alfagta]

The setting error only occurs when i send packages with my can device and Switch the MS on while i'm sending continuously packages.

[jsmcortina]

The setting error only occurs when i send packages with my can device and Switch the MS on while i'm sending continuously packages.

That's probably the problem, the CAN module likely needs to see a clear bus to be able to initialise. You'd have to read the Freescale datasheet for the part (MC9S12XEP100) to be sure.

James

[Reverant]

On a microsquirt module, I've also seen the MCP2551 being placed 180* from the factory!

[racingmini_mtl]

On a microsquirt module, I've also seen the MCP2551 being placed 180* from the factory!

That's not good! But it's good to know that this has been seen. However, in this case it can't be the issue since there has been some transmission which would not happen with a reversed chip.

Jean

[Alfagta]

Hello,

the tranmission to the MS is working now.
Now it's time for the receive from the MS.

[Alfagta]

Hello,

can communication works fine now.
But i have another question, in the "Can Receiving" i can choose 24 Can ADC Inputs.
But it is not possible to set 24 Can ADC Inputs because there are only 16 fields.

So why do we have 24 ADC Inputs?

[jsmcortina]

So why do we have 24 ADC Inputs?

You can fetch data into them using the "CAN polling" system.

James

[Alfagta]

You can fetch data into them using the "CAN polling" system.
James

Yes i know but this is the "old" Megasquirt Can Protocol or isn't it?

[jsmcortina]

You can fetch data into them using the "CAN polling" system.
James

Yes i know but this is the "old" Megasquirt Can Protocol or isn't it?

Yes, but you can use them at the same time.

James

[Alfagta]

And if i will use them i had to implement the Original Megasquirt Can Protocol which i don't fully understand right now.
Because the alignment of the Data in the Register's are not the same as standart Can Protocol 2.0A/B

[jsmcortina]

And if i will use them i had to implement the Original Megasquirt Can Protocol which i don't fully understand right now.
Because the alignment of the Data in the Register's are not the same as standart Can Protocol 2.0A/B

If you do want to do that, take a look at the protocol document in http://www.msextra.com/doc/pdf

James

[Alfagta]

I can Request Data from the MS now.
I also can parse an request from the MS.
But i don't relly know how the Response for an MS Request has to Looks like.
For ADC Polling i get the following Message from the MS:
From id:0
To id:5
Var Block:7
Var Offset:2

So how has the Response to be?

[thokes82]

Did you see the Teensy or Arduino posts in the expansion boards section of this forum? They contain both protocols, MS and standard. I suggest to take a look at https://github.com/merkur2k/MSCan_Gauge ... /README.md
that is how I learned it...

[jsmcortina]

Did the PDF document not explain it clearly enough?

James

[Peter Florance]

On a microsquirt module, I've also seen the MCP2551 being placed 180* from the factory!

That would do it...