Serial to CAN Gateway in new Black Jaguars?

[Paul Copioli]

Trusted mode and untrusted mode are no longer necessary. The current Jaguar firmware expects a "token" when sent a throttle request via CAN. This token is generated by the cRIO. If the CAN frame setting throttle does not contain the token the Jaguar sets its output to 0. This latest implementation allows teams to create there own CAN nodes without having to use PWM cables and allows teams to generate CAN frames over Ethernet.

-Mike Copioli

[imac256]

Originally Posted by ajlapp

I previously recall someone mentioning that both pwm an CAN cables had to be connected to a jaguar for a heartbeat message. It sounds to me like this isn't the case.

My interpretation of that is that the Jaguars can only receive signals over one medium or the other (CAN or PWM). I believe that this means they can both be used, like CAN for a primary controller and PWM signals as a backup if for instance your Black Jaguar dies and you no longer have a convertor. That would still allow for operation of other motors if you can detect the loss of signal.

Just my interpretation, I would suggest a Q&A be posted about this point thought if this is actually going to be used.

[EricVanWyk]

I think the rules are pretty clear. CAN or PWM - choose one.

As Mike said, the "both" option is vestigial and not legal for 2010. This is actually a boon, the "both" option is ugly to be honest.

[Vikesrock]

Team Update #1 has clarified the issue of connecting sensors directly to the Jaguar inputs.

It is now legal to connect sensors or custom circuits to the Jaguar inputs per rule <R68-H>

[woodk]

Has anyone got current mode to work on the jaguars?

Or any other mode other than voltage?

I got it running from a PC using the bdcomm (I think its called) app. However, the c++ code supplied only supports voltage mode. I've been trying to modify it to add other modes, but no success yet.

- Kevin

[biojae]

Originally Posted by woodk

Has anyone got current mode to work on the jaguars?

Or any other mode other than voltage?

I got it running from a PC using the bdcomm (I think its called) app. However, the c++ code supplied only supports voltage mode. I've been trying to modify it to add other modes, but no success yet.

- Kevin

What does current mode do?
I know that the jaguar can adjust the amount of current drawn through pulse-withing the motor power, but is it running at full speed during that time?
I have only tried experimenting with the voltage control mode at this time, but the low speed control (over CAN) seems to be much better then before.

[Al Skierkiewicz]

Kevin,
The Jaguar controls average current by pulse width modulation but the pulses can only go between 0 volts and the battery terminal voltage (12 volts nominal.). Are you thinking of current sense? That is available through the CAN bus. There is a series resistor built into the Jaguar and the voltage drop across that resistor can then be used to calculate current through the device.

[Mike Copioli]

Originally Posted by biojae

What does current mode do?

Current control mode allows users to servo the output of the Jaguar to a given current. PID gains can be set to change the Jaguars response to changing conditions. The maximum current that can be obtained if finite and determined by several factors including the maximum output voltage and duty cycle of the Jaguar.

[Zanfardino2892]

Are the black jags (MDL-BDC24) legal this season. Where is this referenced? and what are the advantages.

[Al Skierkiewicz]

Under this rule for starts...
<R42> Items specifically PROHIBITED from use on the ROBOT include:

D. Motor speed controllers other than Innovation First, Inc. “Victor 884” speed controllers or Luminary Micro/Texas Instruments “Jaguar” (MDL-BDC or MDL-BDC24) speed controllers,

You will also find reference to the Black version needing to be the first in line when using the CAN bus.