Question about proper wiring and considerations

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Question about proper wiring and considerations

Postby redheadedrod » Sat Jun 03, 2017 3:32 am

At last I will be hooking my CarBerry to my '09 Cadillac CTS. This vehicle has both canbus and swcan.

First of all I plan to setup two ODBII ports, socket to connect to both buses on their respective channel 1, plug to connect to both buses on their respective channel 2. In theory I could connect them together and basically build a loop back test to test that the ports are both working...

In practice I will likely use this device in one of two modes. Either just connect the socket to the car for normal communications stuff or also connect a diagnostic device into the plug so I can look at what is being sent between the diagnostic device and vehicle.

Note that the socket that will plug into the car will have any extra lines to it that are useful...

The Wiki is a little unclear for some of the wiring so I want to post how I want to wire this to see if I am correct.

I will ignore the GP and V I/O lines since I don't plan to use them for this application.
Thought I read the UART lines can be used for another protocol but not sure. If they can I am not sure which pins to go to?
Not sure which pin the LIN goes to on a standard ODB connector?

I mistakenly ordered a spare general wire setup so I plan to permanently solder one in this manner. I won't cut unused wires but will protect them and tie them up in case I want to use in the future.

So please verify that my wiring is correct.
Code: Select all
Pin     Socket (Goes to car)   Plug (Diagnostic device can connect)         
1   -   SWCAN chan 1           SWCAN 2
4   -   Chassis Gnd            Chasis Gnd       (Will combine together so the same ground will go to both)
5   -   Signal Gnd             Signal Gnd        (Will combine together so the same ground will go to both)
6   -   CAN HI chan 1          CAN HI Chan 2
14  -   CAN Lo Chan 1          CAN Lo Chan 2
16  -   +12 volt               Ignition out  - Will only be powered up when CB is online
?   -   LIN                    LIN    (Allows to still monitor but can't bridge)


Ignition - Will be connected to +12 volt with a switch so can be turned on and off manually.
redheadedrod
 
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Joined: Wed May 04, 2016 5:50 pm

Re: Question about proper wiring and considerations

Postby redheadedrod » Sat Jun 03, 2017 3:50 am

The Wiki is lacking in many areas including series connection but I believe this to be a series connection.

If I read the information correctly I should be able to bridge the two canbus channels and also separately bridge the two swcan buses. This would allow communications between channels on each bus to be passed back and forth without modification but allow me to monitor what data is received by which channel on which bus. So in essence in this mode any devices normally connected to the ODB port could be monitored without affecting data sent between the device and the vehicle but could be monitored and/or logged by the CB device.

I am also guessing that I SHOULD be able to inject my own data if desired by sending data directly to a bus and channel , is that disabled when in series mode or does it send to both channels?

If I want to modify the data received from a device before sent to the vehicle or vice versa I would have to connect in parallel mode and do all of the transferring manually?

Thank you!

Rodney
redheadedrod
 
Posts: 19
Joined: Wed May 04, 2016 5:50 pm

Re: Question about proper wiring and considerations

Postby PAOLOPED » Fri Jun 16, 2017 4:38 pm

Hi Rodney,
You can physically connect as you described.
When you activate the SERIES mode, you can only have 1 bridge at a time.
GMLAN1 - GMLAN2
Or
CAN1 - CAN2
In SERIES mode, Carberry attempts to recognize the vehicle profile automatically and it copies the messages from port1 to port2 and vice versa.
Only steering wheel messages can be modified by internal functions, while messages can not be transmitted.
To do what you want, you should activate USER mode and fully manage receiving and transmitting with your program on Raspberry.
However, the messages can be many and very close, so we can not assure you that the speed will be enough.
In any case, as the microcontroller has only 2 CAN ports, you can always do just 1 bridge at a time.
Hoping to have answered your doubts,
Thank you and wish you a good day.
Best regards.
PAOLOPED
 
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