View Single Post
  #18   Spotlight this post!  
Unread 09-11-2010, 20:21
kamocat's Avatar
kamocat kamocat is offline
Test Engineer
AKA: Marshal Horn
FRC #3213 (Thunder Tech)
Team Role: Mentor
 
Join Date: May 2008
Rookie Year: 2008
Location: Tacoma
Posts: 894
kamocat is just really nicekamocat is just really nicekamocat is just really nicekamocat is just really nicekamocat is just really nice
Send a message via AIM to kamocat Send a message via MSN to kamocat
Re: Joystick motion to CAN connected jaguar

Quote:
Originally Posted by Radical Pi View Post
Well if it returns zero during the actual running of the code and the 2CAN can retrieve a version and it doesn't work over Serial but everything works in LabVIEW, then there must be a problem in the CANJaguar.cpp file.

2 parts to this one:

Marshal: In LabVIEW's Get Firmware Version, is 0x80000000 OR'd into the ID?

sam: Go into the function GetFirmwareVersion in CANJaguar.cpp (line 866 for me) and replace this line with a different version:

Code:
ORIGINAL:
	// Set the MSB to tell the 2CAN that this is a remote message.
	getTransaction(0x80000000 | CAN_MSGID_API_FIRMVER, dataBuffer, &dataSize);

REPLACE WITH:
	// REMOVED: Set the MSB to tell the 2CAN that this is a remote message.
	getTransaction(CAN_MSGID_API_FIRMVER, dataBuffer, &dataSize);
That ORing only occurs in the GetFirmwareVersion function and seems to be the only thing that sets it apart from any other message. Also looking back through the revision logs on svn that code was introduced around the same time I started seeing the problem.

EDIT: It appears that Java had the same problem at one point and the firmware check was bypassed as a workaround
No, the OR is not there in the LabVIEW version.
There is just the decimal value 512 ORed with the device number.
In hexadecimal, that should be 0x0b00

What's weird about ORing 0x80000000 is that it makes TRUE the highest bit of the Arbitration ID. The highest 3 bits of the arbitration ID should be reserved.

By all means, take it out, and comment what and why you did.
__________________
-- Marshal Horn
Reply With Quote