setCANfilter

[lpettipa]

Can anyone provide a simple example of how to use setCANfilter? Say to read only one particular CAN id only?

[Adli]

Ping - Also Interested.

Right now im achieving this using the logging script provided in the wiki - but im chasing a CAN stream of data that needs to be masked, and this seems like the only way?

I'd like to work this into a specific channel (Say ID 268) and mask 2 bytes (#2,3) with 0FFF...

Cant seem to use Hex, so can i use 1+0?

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setCANfilter(0, 268, 0, 00110000, 0111)

[Adli]

FYI, my code for logging a single CAD ID is below, shown with ID 999, adapted from ASL RCP2 Wiki
https://wiki.autosportlabs.com/CAN_Bus_logger#Script
The key change is

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if id == 999 then

Full Lua Script

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--500K baud. set your baud rate here.
initCAN(0, 500000) 

setTickRate(30)  --onTick() will be called at 30Hz.

--this function drains all pending CAN messages
--and outputs messages to the log
function outputCAN()
	repeat 
		id, ext, data = rxCAN(0, 100)
		if id == 999 then
			print(id ..', ')
			for i = 1,#data do
				print(data[i] ..', ')
			end
			println('')
		end
	until id == nil
end
 
function onTick()
	outputCAN()
end

[lpettipa]

Adli,

I didn't know how to do hex either - but learned today - very easy. So if DEC=1280 (which is hex 500), were you would enter 1280, enter 0x500. Worked for me.

But if you print the can ID, it will still be in DEC. So I used this little function I found on google:

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function DEC_HEX(IN)
    local B,K,OUT,I,D=16,"0123456789ABCDEF","",0
    while IN>0 do
        I=I+1
        IN,D=math.floor(IN/B),math.mod(IN,B)+1
        OUT=string.sub(K,D,D)..OUT
    end
    return OUT
end

just stick this function code in before your looping program.

so your print would look like this:

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println(DEC_HEX(ID))

ID will print in HEX

[lpettipa]

so I'm trying to read values off a really busy CAN bus on a few specific ID's. Using the same method as Adli. Not sure it will help anyone else, but my tick rate was 100, and not much was coming thru - set tick rate to 1000, and now data is flowing.

This is not a solution - I think setCANfilter is the solution, awaiting firmware rev 2.10 to fix this......