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Using CAN acceptance filter on LPC2129

Using CAN acceptance filter on LPC2129

2005-06-21 by me_mickey_2006

I'm having problems with using acceptance filter, I used examples
BlinkyCAN and FullCAN but I have problems anyways.

1. Does anyone have any material on the matter except poor lpc2129
datasheet?

2. I tried to send CAN message with identifier 0x00000063 in Extended
Frame Format, I used no filtering AFMR = 2, and I inspected received
message and it turns out identifier is now 0x00630000, why is that as
if 29 bit identifier is cut to 11 bit identifier?

Re: Using CAN acceptance filter on LPC2129

2005-06-21 by me_mickey_2006

Please ignore this second question, my fault, the identifier in
standard or extended format is received as 0x00000063
Show quoted textHide quoted text
> 2. I tried to send CAN message with identifier 0x00000063 in Extended
> Frame Format, I used no filtering AFMR = 2, and I inspected received
> message and it turns out identifier is now 0x00630000, why is that as
> if 29 bit identifier is cut to 11 bit identifier?

Re: [lpc2000] Using CAN acceptance filter on LPC2129

2005-06-22 by Steffen Rose

Hi,

On Tuesday 21 June 2005 19:00, me_mickey_2006 wrote:
> I'm having problems with using acceptance filter, I used
> examples BlinkyCAN and FullCAN but I have problems anyways.
>
> 1. Does anyone have any material on the matter except poor
> lpc2129 datasheet?

My problem at the first days I implemented the acceptance filter:
You have to sort all lists, first all sorted ID's from the first 
CAN, than all sorted ID's from the second CAN.. . I think, no 
holes are allowed. The last entry on the list must be a 
disabled/enabled entry for the maximum ID.

-- 
Steffen Rose

Re: Using CAN acceptance filter on LPC2129

2005-06-22 by me_mickey_2006

I have solved the matter, and have to say this:

It is VERY VERY IMPORTANT to look carefully at datasheet as some
details are offten oversighted, so my oversight was not adding bits
(15.-13. for standard identifiers and 31.-29. for extended
identifiers) for controller (channel that receives specified ID).

So Apart from ID 11 or 29 bit you also have 3 bits telling for which
can controller the ID is ment for.

For example:

If you want to receive message from ID = 15 and you want to receive it
on CAN channel (controller) 1 then for standard identifiers you should
write to AFRAM 0x200FF7FF for standard identifiers and 0x2000000F for
extended identifiers.

Re: Using CAN acceptance filter on LPC2129

2006-03-14 by David Mercier

Hi !

I'm trying to use the Accpetance Filter on the LPC2129 and I can't get it to
work... Do you have any code that would help me to make it work ?

Best regards

David Mercier

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