Anderson PowerPole for CAN bus?

[otherguy]

Originally Posted by mbshark

We are currently trying to decide between APP 15 amp connectors and the pwm connectors for the CAN connections on the Talon SRX's. I am wondering if the APP 15 amp connectors would be frc legal as the maximum gauge wire is 20 AWG and the Talon SRX's CAN wires are 22 AWG. I would hate to have the team rewire the whole thing during a competition because of a research mistake.

The connector is rated at 15amp. You're not actually going ot be putting 15 amps through it. There's no rules preventing you from using connectors rated for higher currents than required in your application.

My guess is that the 15A connector was suggested because it's the smallest gauge connector available for the power poles. You're likely to have trouble crimping a larger connector on such small gauge wires, and if you succeed without breaking the wire, you're likely to have failures down the line.

[AllenGregoryIV]

Very interesting thread. We're going to try out the APPs on our prototype robot since that's what we have right now but if we run into any problems I like the idea of combining these two solutions.

Originally Posted by Peter Johnson

We're using Hansen Hobbies' 2-pin 0.1" LP (latching polarized) connectors (http://www.hansenhobbies.com/product...nlpconnectors/) for our CAN bus. They use different pin inserts than their other 0.1" connectors, but you can use the same crimper for both. They're a tiny bit longer when mated than a standard PWM but they're much more robust thanks to the latching feature and the polarization keeps you from accidentally swapping CANH and CANL. Basically we put a male and and a female connector on each Talon; makes daisy chaining a cinch.

Originally Posted by otherguy

During beta testing we decided to crimp the CAN talons with a three pin header with the center pin left empty. We did this on both ssets of CAN cables on the controller.

Reasons for doing it this way:

• we already had the crimpers and connectors for PWM cables.
• female headers prevent exposed contacts that could short to the chassis
• using a 3 pin connector with the center pin empty allows the controllers to be plugged in to the roboRIO maintaining support for PWM capability.
• it makes it easy to daisychain controllers together, just use a 3pin male header (see below)

The pin headers for connecting two female cables: http://www.hansenhobbies.com/product...pt1in_srfma40/

Using the 3 pin versions or the Hansen Hobbies locking polarized connectors would allow you to still use PWM if you wanted to but also prevent you from flipping polarity on accident. The 3 pin housings aren't much more expensive than the 2 pin. You can daisy chain with out much hassle or the need for special connectors. From one of the non-talon nodes you would just need a few wire pairs with just the male or female ends of the connectors attached.

[Al Skierkiewicz]

Allen,
We like the Victors and will likely use them for this season. There are a variety of other connector solutions available through outlets like Digikey (who is a big FIRST supporter in Minnesota) and others. As Don has pointed out above, solutions need to maintain buss impedance in some fashion (it is a transmission line interface after all.)

Mb,
There is relatively little current flow in this bus so it does not come under the wire gauge rules. Please remember that the those rules relate current protection to wire size. A dead short on the CAN buss will not burn up the wire.

I would use a locking connector of some type that is easy to terminate and difficult (read as 'impossible') to connect backwards. The RJ-11/45 used on the Jaguar is a pretty reliable device, crimpers are available everywhere for cheap and the connectors are easy to get. As always, I tend to discourage solid wire on moving devices but there is plenty of stranded wire options for these connectors. Spend the money for the right connectors and crimper if you want reliable operation.

[ozrien]

CAN connector coming soon, see attached image.

[AllenGregoryIV]

Originally Posted by ozrien

CAN connector coming soon, see attached image.

any idea on pricing?

[Ken Streeter]

Originally Posted by ozrien

CAN connector coming soon, see attached image.

Looks like a good solution - I like it!

Personally, I'd love to see that block be part of the TalonSRX if a hardware rev gets performed in future years.

For that matter, I really wish the 10-pin "encoder connecter" were also weidmuller connectors -- the 5x2 .05" header connector is less than optimal for interfacing to directly.

[kyle_hamblett]

We are using the same connectors that would be on the Talon SR or Victor so if we ever decide to utilize PWM over CAN, we can do so without having to change the controller wiring.