canbus communication

[ilkerozturk58]

Dear CCS users ,

i have a problem about canbus communicatiom these problems i want to read some datas from the ecu and i know that coolant temperature at 0x268 in pwm table how can i take datas from this address ? If you have example or you know a way for this application can you share me.

my ecu's can communication datasheets is here; http://www.msextra.com/doc/ms3/can.html


thank you
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[dyeatman]

This looks like to me to have nothing to do with PIC or CCS code unless you
are just wanting to use serial on the PIC via USB to communicate with the
Megasquirt main node.

If that's the case, search for examples on this board of RS232 and put
something together. RS232 to CAN converters typically don't require any
special code.
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[RF_Developer]

That datasheet is about connecting up the CAN bus on the Megasquirt box. It has nothing to do with the data that sent from ECUs and so on on the CAN bus.

CAN is a message passing bus. You need to find out what message sent from the ECU has the data you want, and how you need to find out how to interpret it. Also you *may* need to find out what message you need to send to ask for that data. That datasheet tells us, and you, nothing about that. All the information you need will be in another document somewhere. The Megasquirt box seems to be a generic datalogger/GPIO box with a CAN interface targeted at automotive applications, and so doesn't know anything about what the data it collects means. In other words you get an ADC value from it, and you then have to convert that to temperature. The box itself reads voltages and reports ADC values, not temperatures.

Yes, you can use PICs with CAN peripherals to send and receive those messages, and you can use CCS C to program that PIC, but you are several steps away from that at the moment, and so we can do almost nothing to help you right now.

[ilkerozturk58]

Firstly, I apologize for late answer dear users,
I know there is gpıo board for megasquirt ecu and i dont want using that. In second question if i know that which address is in my data at can line can i use pic series and can module ? I think a way with pic
1) giving ID
2) input data address to my pic for ecu
3) sending data request to ecu
4) wait coming data from ecu
I put a picture for more information, please click to link. I only want explain me taking data from specific address with sample codes.

http://upload.hizliresim.com/upload.php

Best Regards

http://o1307.hizliresim.com/1c/g/q7vxs.jpg
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