New to 2CAN and Jaguar

[mikets]

Our team has been using Victors for a number of years. We finally want to embrace Jaguar and try CAN bus for this year. We've got 4 Black Jaguars and a 2CAN (not V2 though). I quickly written some simple code to test the Jaguars but it doesn't work. There must be some sample code written somewhere for CANJaguar on 2CAN. Would somebody point me to it? To summarize what my simple code does:

class MyRobot: public SimpleRobot
{
private:
    CANJaguar m_jagLeft;
    CANJaguar m_jagRight;
    Joystick m_leftStick;
    Joystick m_rightStick;
 
public:
    MyRobot():
        m_jagLeft(CANID_LEFT_JAG, CANJaguar::kSpeed),
        m_jagRight(CANID_RIGHT_JAG, CANJaguar::kSpeed),
        m_leftStick(JOYSTICK_LEFT),
        m_rightStick(JOYSTICK_RIGHT)
    {
        m_jagLeft.SetSpeedReference(CANJaguar::kSpeedRef_QuadEncoder);
        m_jagRight.SetSpeedReference(CANJaguar::kSpeedRef_QuadEncoder);
 
        m_jagLeft.SetPositionReference(CANJaguar::kPosRef_QuadEncoder);
        m_jagRight.SetPositionReference(CANJaguar::kPosRef_QuadEncoder);
 
        m_jagLeft.SetPID(DRIVE_KP, DRIVE_KI, DRIVE_KD);
        m_jagRight.SetPID(DRIVE_KP, DRIVE_KI, DRIVE_KD);
 
        m_jagLeft.ConfigEncoderCodesPerRev(DRIVE_ENCODER_CODES_PER_REV);
        m_jagRight.ConfigEncoderCodesPerRev(DRIVE_ENCODER_CODES_PER_REV);
 
        m_jagLeft.EnableControl();
        m_jagRight.EnableControl();
    }
 
    ....
    ....
    ....
   void OperatorControl(void)
   {
        while (IsOperatorControl())
        {
            m_jagLeft.Set(-m_leftStick.GetY());
            m_jagRight.Set(-m_rightStick.GetY());
            Wait(0.005);
        }
    }
};

I printed the joystick values to dsLCD and I got reasonable values when reading the sticks. So it means the m_jagXXXX.Set() is not doing anything. All the jags are assigned correct IDs (2 and 3) and have firmware version 92 on them. The 2CAN has a green light and I can access its web page in my browser on http://10.4.92.10. I even plugged in the serial cable directly to one of the jags and ran bdc-comm-92.exe tool. The tool enumerated saw the jag ID 2 and 3 and I was able to set some values on each of the jags and made them turn. That means the CAN bus is wired properly and the 2CAN interface with the CAN bus successfully (through the web interface). The only thing I am unsure is if the cRIO can communicate with the 2CAN. I assume the cRIO knows how to communicate with the 2CAN since I have imaged the cRIO with "2CAN" selected, so the 2CAN driver should be running. And I am also assuming the cRIO will communicate with the 2CAN using 10.xx.xx.10 as its IP address. What else did I miss?

[linuxboy]

What version image are you running on the cRIO? I don't think the cRIO will talk to Jags with out the latest FRC image for safety reasons. I would check this link. On the side it has BDC-COMM v100, as well as FRC firmware v100. Try flashing that firmware and see if your results change.

Oliver

[mikets]

Thanks for the info. I have flashed all the Jags with firmware version 100 but it is still not working. The NetConsole has a lot of messages about timing out waiting for the Jag.

<Code>-44087 ERROR: status = -44087 (0xFFFF53C9) sendMessage ...in setTransaction() in C:/WindRiver/workspace/WPILib/CANJaguar.cpp at line 406
FRC: JaguarCANDriver timed out waiting to receive a response from a Jaguar.
<Code>-44087 ERROR: status = -44087 (0xFFFF53C9) sendMessage ...in setTransaction() in C:/WindRiver/workspace/WPILib/

What else did I miss?

[Mike Copioli]

Originally Posted by mikets

The only thing I am unsure is if the cRIO can communicate with the 2CAN. I assume the cRIO knows how to communicate with the 2CAN since I have imaged the cRIO with "2CAN" selected, so the 2CAN driver should be running. And I am also assuming the cRIO will communicate with the 2CAN using 10.xx.xx.10 as its IP address. What else did I miss?

The 2CAN acts as a gateway to CAN the cRIO simply passes the CAN frame over UDP, the 2CAN has no other interaction with the CRIO.

What you see in the web dash is the result of interactions between the 2CAN and the JAG's over CAN, this and the green led on the 2CAN means you are successfully communicating with the jaguars over CAN and you are successfully communication with the 2CAN plugin on the cRIO. Your problem is most likely in your code.

I noticed that you are calling the closed loop functions. If you are trying to just control the Jag in voltage control mode you do not need to to do this. Also I do not see where you init the Jaguars.

The functions used in CAN are the same regardless of the gateway used (serial or 2CAN). The only difference is the plugin. Make sure you have the most recent plugin and 2CAN firmware (version 2.18).

A couple questions:

1. What is the state of the Jaguar LED? blinking orange or solid orange.
2. What version of 2CAN firmware and plugin are you running?

The -44087 is a timeout error.

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[mikets]

Originally Posted by Mike Copioli

I noticed that you are calling the closed loop functions. If you are trying to just control the Jag in voltage control mode you do not need to to do this.

What do you mean? The loop is reading the joystick values and programming the Jaguar in speed mode accordingly. If that's not the proper way to program the Jaguar, please show me the proper way.

Originally Posted by Mike Copioli

Also I do not see where you init the Jaguars.

How do you initialize the Jags? Wouldn't the CANJaguar constructor initialize it for me? I looked at the source code for the CANJaguar module and it calls the InitCANJaguar method. In the InitCANJaguar method, it checks the firmware version to make sure it's between 92 and 3329. Then it send a transaction to the Jag to enable the specified operating mode. That should be enough to initialize the Jags, right?

Originally Posted by Mike Copioli

The functions used in CAN are the same regardless of the gateway used (serial or 2CAN). The only difference is the plugin. Make sure you have the most recent plugin and 2CAN firmware (version 2.18).

When I imaged the cRIO, I selected 2CAN. According to documentation, this will automatically add the 2CAN driver to the cRIO plug-in list.

Originally Posted by Mike Copioli

A couple questions:

1. What is the state of the Jaguar LED? blinking orange or solid orange.
2. What version of 2CAN firmware and plugin are you running?

The Jaguar LEDs are blinking either Yellow or Green depending on which angle you are looking at them. According to the Diagnostic page of the 2CAN web dash:

Version: 2.5

Build Date: Mar 13 2011 04:56:34

Is it the latest? If not, please point me to the latest firmware. It's not easy to determine which version I should download. According to the web site:

Downloads for FIRST:

• 2CAN User Manual ver_1.4 (pdf) (Updated 1/10/2011)
• 2CAN Firmware ver_2.18 (crf) (Updated 12/21/2011)
• 2CAN Firmware (2.5) (Updated 3/13/2011)
• 2CAN Firmware (2.1) and Plugin (SVN rev 66) for FRC cRIO (Updated 1/29/2011)
• Wind River Kernel Module Plugin Source (SVN rev 66) for FRC cRIO (Posted 3/12/2011)
• 2CAN Firmware (2.1) and Plugin (SVN rev 64) for FRC cRIO (Updated 1/15/2011)

I picked version 2.5 because the other seems to be for 2CAN V2. So I am not sure if I picked the correct version.

Thanks for your help.

[mikets]

I took a risk and tried flashing the latest date firmware which is v2.18 (12/21/2011). It looks like the old 2CAN can take this firmware as well. After the firmware update, I can still access the 2CAN dashboard and can see the jags and their data. But unfortunately, the cRIO is still timing out waiting for the Jags to respond. I must be missing something simple.

I have attached the whole code since it is highly likely I missed something in the code.

[jhersh]

As long as you are getting a timeout from a send message call, there is something wrong with either your wiring or your configuration. Once you get past that, then you'll need to make sure you are calling all the right methods to enable the closed-loop control. Your first code snippet was much closer than this most recent post.

Calls like this are needed:

speedJag.SetSpeedReference(CANJaguar::kSpeedRef_Qu adEncoder);
speedJag.ConfigEncoderCodesPerRev(360);
speedJag.SetPID(P, I, D);
speedJag.EnableControl();
speedJag.Set(stick.GetAxis(axis) * 150.0);

Try using the jag in speed mode outside of RobotDrive first.

-Joe

[mikets]

Originally Posted by jhersh

As long as you are getting a timeout from a send message call, there is something wrong with either your wiring or your configuration.

Wiring should be fine. I have tested it with the bdc-comm-100.exe tool and was able to see and run all motors. So it means the CAN bus is good. I am also able to see the 2CAN and all the Jags on the network (i.e. can access the 2CAN dashboard on 10.4.92.10 and see the status of all the jags). So it means the ethernet connection to the 2CAN is good. What other wiring could be wrong?

Originally Posted by jhersh

Once you get past that, then you'll need to make sure you are calling all the right methods to enable the closed-loop control. Your first code snippet was much closer than this most recent post.

Yeah, I decided to redo the program with standard template and thinking I don't care about the encoders yet so I skipped the encoder related initialization. So you are saying they are still required?

[jhersh]

Originally Posted by mikets

Wiring should be fine. I have tested it with the bdc-comm-100.exe tool and was able to see and run all motors. So it means the CAN bus is good. I am also able to see the 2CAN and all the Jags on the network (i.e. can access the 2CAN dashboard on 10.4.92.10 and see the status of all the jags). So it means the ethernet connection to the 2CAN is good. What other wiring could be wrong?

Probably nothing. Are you checking for errors or messages on the console being printed by the 2CAN plugin? Have you tried a BlackJag bridge?

Originally Posted by mikets

Yeah, I decided to redo the program with standard template and thinking I don't care about the encoders yet so I skipped the encoder related initialization. So you are saying they are still required?

They are required for closed loop mode... without some process variable, the controller does nothing. You may want to try simple PercentVbus mode first. Start simple and all. Verify you can talk to the Jags at all. Make sure your device numbers in the constructors match what you configured.

[mikets]

I changed the program as you suggested (new code attached). Notice that I added the jag.Set(30.0) in there outside of the loop. When running it, I heard the motor noise like it had moved but then stopped. When I looked, nothing happened. Then I noticed my voltage is getting low and the Jags are no longer powered. I think my battery is now exhausted. Unfortunately, the mechanical mentor has the charger. So I guess I am done for tonight. But I am excited, it may mean the motor really moved but then the battery died because of the current drawn. If that's the case, it means the jag.Set() outside of the loop worked. If so, the next step is to find out why the ArcadeDrive inside the loop did not work. Since you suggested "speedJag.Set(stick.GetAxis(axis) * 150.0);", does it mean the full range of the Jag is -150.0 to 150.0? How about the ArcadeDrive call? Would the RobotDrive object do the scaling to 150, or do I need to call SetMaxOutput myself? I can't find anywhere in CANJaguar that it scales the outputValue. If that's the case, that explains why the motors didn't move because the outputValue will be below or equal to 1.0 in a full scale of 150.0. I thought everything in WPILib scaled to 1.0. Why is it that we need to multiply 150.0 in jagSpeed.Set()? If the speed mode is really in the range of -150.0 to 150.0, is there documentation somewhere telling me what range is the motor in which mode?

[mikets]

Wait, I found the scaling code in CANJaguar. It is in packFXP16_16. It means the full range is actually +/- 65536. So like I suspected, the outputValues in jag.Set() should always be in the range of +/- 1.0 and the CANJaguar module will scale it to +/- 65536 and send it to the jags. Then why do we need to multiply 150.0? I am confused.

[Mike Copioli]

Originally Posted by mikets

Is it the latest? If not, please point me to the latest firmware. It's not easy to determine which version I should download.

The latest release is indicated by the most recent release date and the version number. version 2.18 is higher than version 2.5.

2.18 .crf for the 2CAN

http://www.crosstheroadelectronics.c...2_18_FIRST.crf

As for the plugin a new one will be released shortly but the SVN rev 66 should work fine.

http://www.crosstheroadelectronics.c...01-29-2011.zip

The latest version is back wards compatible with version 1 2CAN hardware. The only difference between 2.5 and 2.18 is 2.18 supports the device id for a different version of Ethernet silicon inside the 2CAN. All new versions of 2CAN firmware will support both devices.

One thing to note if the 2CAN has a Green LED your problem is not on the CAN side(wiring, termination) the LED can only be green when at least one Jaguar is present on the BUS and responding to enumeration requests from the 2CAN and the the plugin has successfully loaded. If you had bad termination or faulty wiring you would see a red strobing LED and the Jags would not appear in the web dash. Since you are able to see all of your jags in the web dash and the 2CAN LED is green your problem is not in the CAN wiring or termination. This is a very useful tool that can be used to provide quick diagnostics when setting your robot up on the field. Green is good red is dead.

Follow Joe's advice regarding your code as it seems you already have.

[Mike Copioli]

A couple observations:

It appears that at this point all you want to do is control your Jags using voltage control mode, this is the mode that provides the same functionality as pwm and is the default mode in the CANJaguar constructor.

CANJaguar (UINT8 deviceNumber, ControlMode controlMode=kPercentVbus)
Constructor.

You pass in a throttle value between -1 and 1 into Set(). To simplify things I would remove all but one Jaguar from the CAN bus. Make sure you are only calling Set() for the Jag that is on the CAN bus as this will also cause the
-44087 error to appear. Open the web dash to verify the Jag ID. Using only one JAG eliminates the possibility of having more than one jag on the BUS with the same ID, this will also cause the -44087 error as well.

Make sure the 2CAN LED is green if it is RED power cycle the Jag and the LED should turn Green. (FYI if you remove the CAN cable from the JAG the 2CAN led should turn red, removing the Ethernet cable should cause the LED to turn orange, removing both will cause a red LED.)

If the LED is green and you have the correct ID's and you are not sending requests to any other JAG's that are not on the BUS your code should work.

[mikets]

Thanks for the info. I will try that tonight. One question though, if I run the Jags in Voltage mode (kPercentVbus), it means it doesn't need encoder (as versus Speed mode or Position mode). Can I skip the encoder related initializations just to make it even simpler? For example, SetSpeedReference, SetPositionReference, SetPID and ConfigEncoderCodesPerRev?

[Mike Copioli]

Originally Posted by mikets

Thanks for the info. I will try that tonight. One question though, if I run the Jags in Voltage mode (kPercentVbus), it means it doesn't need encoder (as versus Speed mode or Position mode). Can I skip the encoder related initializations just to make it even simpler? For example, SetSpeedReference, SetPositionReference, SetPID and ConfigEncoderCodesPerRev?

Correct, those function calls are only necessary if you want to use the closed loop modes or request encoder/potentiometer position.