CAN Communications.
Moderators: jsmcortina, muythaibxr
Re: CAN Communications.
Im working away on my own dash display too.
At the moment im dumping the can transmissions between the MS3 and the TinyIOx.
Ive worked to how to format the header bytes, but the request data bytes are puzzling me.
An example of my can messages dump:
00->04 = msg_type:MSG_REQ var_blk:07 var_offset:0002 data(hex): 07 40 08
00->04 = msg_type:MSG_REQ var_blk:07 var_offset:0010 data(hex): 07 41 08
04->00 = msg_type:MSG_RSP var_blk:07 var_offset:0512 data(hex): 03 FF 03 FF 03 FF 03 FF
04->00 = msg_type:MSG_RSP var_blk:07 var_offset:0520 data(hex): 03 FF 03 FF 01 2C 01 2A
So, in the first request the data bytes are 07 40 08.
07 = myvarblk
40 08 = somehow is length & offset?
I gather the 8 is length, so that makes 40 0 the offset but shifted left by 1 bit?
IMO, the can_tech doc is too MS internals orientated.
cx_myvarblk, cx_myvaroff, cx_varbyt, etc dont actually specify where that data is located in a normal CAN message (ie, xx bits of the first data byte).
At the moment im dumping the can transmissions between the MS3 and the TinyIOx.
Ive worked to how to format the header bytes, but the request data bytes are puzzling me.
An example of my can messages dump:
00->04 = msg_type:MSG_REQ var_blk:07 var_offset:0002 data(hex): 07 40 08
00->04 = msg_type:MSG_REQ var_blk:07 var_offset:0010 data(hex): 07 41 08
04->00 = msg_type:MSG_RSP var_blk:07 var_offset:0512 data(hex): 03 FF 03 FF 03 FF 03 FF
04->00 = msg_type:MSG_RSP var_blk:07 var_offset:0520 data(hex): 03 FF 03 FF 01 2C 01 2A
So, in the first request the data bytes are 07 40 08.
07 = myvarblk
40 08 = somehow is length & offset?
I gather the 8 is length, so that makes 40 0 the offset but shifted left by 1 bit?
IMO, the can_tech doc is too MS internals orientated.
cx_myvarblk, cx_myvaroff, cx_varbyt, etc dont actually specify where that data is located in a normal CAN message (ie, xx bits of the first data byte).
Toyota Celica GT4/Alltrac with 5S-GTE stroker (2.2L I4 turbo, high CR) on E85 w/FlexFuel.
MS3 + MS3X + KnockBoard + RTC + BT + DIY CAN-IO-Board + DIY CAN Digital Dash.
MS3 + MS3X + KnockBoard + RTC + BT + DIY CAN-IO-Board + DIY CAN Digital Dash.
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Re: CAN Communications.
It does, there's a diagram just under the wordsMWPau wrote:IMO, the can_tech doc is too MS internals orientated.
cx_myvarblk, cx_myvaroff, cx_varbyt, etc dont actually specify where that data is located in a normal CAN message (ie, xx bits of the first data byte).
"The 29 bit CAN message header is divided into blocks across four 8-bit registers"
James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk
My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
Re: CAN Communications.
Yes, there is that nice table for the CAN header.
Something similar would be great for the format of the 3 data bytes of a MSG_REQ packet.
That's what I'm having trouble working out.
Thanks
Something similar would be great for the format of the 3 data bytes of a MSG_REQ packet.
That's what I'm having trouble working out.
Thanks
Toyota Celica GT4/Alltrac with 5S-GTE stroker (2.2L I4 turbo, high CR) on E85 w/FlexFuel.
MS3 + MS3X + KnockBoard + RTC + BT + DIY CAN-IO-Board + DIY CAN Digital Dash.
MS3 + MS3X + KnockBoard + RTC + BT + DIY CAN-IO-Board + DIY CAN Digital Dash.
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Re: CAN Communications.
I updated the http://www.msextra.com/doc/ms3/can_tech.html page with some more information.MWPau wrote:Yes, there is that nice table for the CAN header.
Something similar would be great for the format of the 3 data bytes of a MSG_REQ packet.
That's what I'm having trouble working out.
Thanks
James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk
My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
Re: CAN Communications.
Brilliant.
Thanks very much for that James
Thanks very much for that James
Toyota Celica GT4/Alltrac with 5S-GTE stroker (2.2L I4 turbo, high CR) on E85 w/FlexFuel.
MS3 + MS3X + KnockBoard + RTC + BT + DIY CAN-IO-Board + DIY CAN Digital Dash.
MS3 + MS3X + KnockBoard + RTC + BT + DIY CAN-IO-Board + DIY CAN Digital Dash.
Re: CAN Communications.
http://www.msextra.com/doc/ms3/can_tech.html
Anyone know if this page still exists?
The link is broken
Anyone know if this page still exists?
The link is broken
MS3PU/IOx/CAN-EGT/DBWx2 540ci BBC 325cc int runners (2)innovate LC2 wbo2's, Hilborn ITB injector cnvrtd to EFI, 55LB Inj, d585 coil near plg, 60-2 trg whl & cam ph snsr, Muncie 4spd w/10T VSS, Tilton 7.25" cerametalic cltch 8.5LB flywhl
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Re: CAN Communications.
Yamaha GTS1000 v2 MicroSquirt, B&G 2.891
Yamaha GTS1000 v3 beta MicroSquirt, B&G3.760
Yamaha GTS1000 MSExtra 3.1, Dual VR Board
Yamaha YZF1000 MSExtra 3.1
Yamaha GTS1000 v3 beta MicroSquirt, B&G3.760
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Re: CAN Communications.
Where did you find that ^^ ?
These docs locations changes are frustrating
These docs locations changes are frustrating
Toyota Celica GT4/Alltrac with 5S-GTE stroker (2.2L I4 turbo, high CR) on E85 w/FlexFuel.
MS3 + MS3X + KnockBoard + RTC + BT + DIY CAN-IO-Board + DIY CAN Digital Dash.
MS3 + MS3X + KnockBoard + RTC + BT + DIY CAN-IO-Board + DIY CAN Digital Dash.
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Re: CAN Communications.
Actually, it's quite easy!
Manuals Index link and both CAN updates are at the bottom of the page.
Frustrating maybe, but the files have been updated recently, and I personally think stuff is getting much easier to find and is better organised than before, so I'd bookmark that link.
Mike
Go to the Frustrating maybe, but the files have been updated recently, and I personally think stuff is getting much easier to find and is better organised than before, so I'd bookmark that link.
Mike
Yamaha GTS1000 v2 MicroSquirt, B&G 2.891
Yamaha GTS1000 v3 beta MicroSquirt, B&G3.760
Yamaha GTS1000 MSExtra 3.1, Dual VR Board
Yamaha YZF1000 MSExtra 3.1
Yamaha GTS1000 v3 beta MicroSquirt, B&G3.760
Yamaha GTS1000 MSExtra 3.1, Dual VR Board
Yamaha YZF1000 MSExtra 3.1
Re: CAN Communications.
Ah so it is
I only kept this page bookmarked, so missed it: http://www.msextra.com/manuals/ms3manuals/
I only kept this page bookmarked, so missed it: http://www.msextra.com/manuals/ms3manuals/
Toyota Celica GT4/Alltrac with 5S-GTE stroker (2.2L I4 turbo, high CR) on E85 w/FlexFuel.
MS3 + MS3X + KnockBoard + RTC + BT + DIY CAN-IO-Board + DIY CAN Digital Dash.
MS3 + MS3X + KnockBoard + RTC + BT + DIY CAN-IO-Board + DIY CAN Digital Dash.