Talon SR vs Talon SRX vs New Victor vs Spark

[Kevin Sevcik]

I'd just note that the srx is even more convenient if you're okay with buying into the Vex ecosystem. The versaplanetary encoder and srx mag encoder are both pretty nice and plug straight into the talon srx. Possibly with an extension cable and connector unless you're investing in the parts to make custom length cables.

[Tom Bottiglieri]

254 absolutely loves the Talon SRX. Our entire robot is powered by them and we use the onboard PIDF controllers along with the CTRE encoder to control our turret angle, flywheel velocity, and drive wheel velocity for autonomous mode. Tuning these controllers was easier than anything we've tried in the past thanks to the heavy filtering and fast update rates they can achieve.

I recommend them to all teams and don't see us switching away any time soon.

[Thad House]

Originally Posted by Tom Bottiglieri

254 absolutely loves the Talon SRX. Our entire robot is powered by them and we use the onboard PIDF controllers along with the CTRE encoder to control our turret angle, flywheel velocity, and drive wheel velocity for autonomous mode. Tuning these controllers was easier than anything we've tried in the past thanks to the heavy filtering and fast update rates they can achieve.

I recommend them to all teams and don't see us switching away any time soon.

If using the built in PID for drive control, are you guys using a gryo to keep the heading straight? If so, how do you keep it straight, as I don't see a way to sync talons on different sides. Do you just adjust the velocity setpoint based on the gyro angle offset?

[Tom Bottiglieri]

Originally Posted by Thad House

If using the built in PID for drive control, are you guys using a gryo to keep the heading straight? If so, how do you keep it straight, as I don't see a way to sync talons on different sides. Do you just adjust the velocity setpoint based on the gyro angle offset?

Quite simply, yes. There is a higher level controller on the robot adjusting for robot position (including heading). That controller generates wheel velocities which get fed into the Talon. This is nice because we can be generally confident the wheel will try as hard as possible to do the right thing without having to manage it manually.

[gerthworm]

One other consideration we had this year:


1) CAN enables you to do a lot more (we especially like the current draw measurement of the SRX's), but with a daisy-chained architecture could also be a liability - if your CAN cable comes unplugged from the RIO, your whole robot is dead.

Our general philosophy of recent year(s) has been PWM-style controllers for drivetrain (where you need lots of raw super reliable power) and SRX/CAN controllers for things like shooter motors or arms which need finer control. Just a rule of thumb, though...

Updates after talking to our electrical lead:

1) I was mistaken, Spark controllers were not known to have an issue. SD540's did have a low-voltage interesting behavior, but that was fixed in the B revision.
2) PWM controllers are also much lower cost. In reality, that's what would drive us to use them unless there is a sensor associated with that particular mechanism.

[Drakxii]

We used the Talon SRX they have some nice upsides, just two things I didn't like. The reset button is a little big and some of them got stuck on our bot. Also I wished they had a version for terminal studs, instead of everything being soldered in place.

Ideally you would use the Talon SRX where you need the PIDF controllers and then Sparks or TalonSR everywhere else.

[gerthworm]

Originally Posted by Ether

I think you may be confusing the Spark with a completely different motor controller.

Updated, you are correct. Thank you for helping me catch that.

[GreyingJay]

Just a little note about the Talon SRX - if you use them in CAN mode, you need to pre-program them with a CAN ID.

"Well, duh", you are saying.

Well... on our testbed, we wired the Talon SRX in PWM mode and made sure things worked. Then we moved them onto the competition robot, electing to rewire them in CAN configuration.

Everything was forgotten until 20 minutes before midnight on Bag and Tag day, when we were scrambling to finish the robot, and write some simple test code to make sure it would work.

CANTalon intakeLeft = new CANTalon(

"Hey, does anyone remember what CAN ID the --- oh. Oops."

We ended up programming their CAN ID's at our first competition.