Cabling between Talon SRX and VersaPlanetary Integrated Encoder

[Ken Streeter]

We're huge fans of using an encoder on nearly every motor on the robot. Last year, we used the TalonSRX with an encoder wired directly to the TalonSRX for all our PID control loops (velocity control PID for each of the four mecanum drive wheels, and position control for each of our two elevators).

We've also been fans of the BaneBots planetary P60 gearboxes, having used them successfully for many years (after learning their foibles.)

This year, though, we're considering switching to VersaPlanetaries, in order to take advantage of the COTS VersaPlanetary Encoder solution - http://www.vexrobotics.com/217-5046.html

However, one of the tricky things on the TalonSRX and the CTR encoder is the use of the fragile little TalonSRX Data Cable. ( http://www.vexrobotics.com/217-4358.html or http://www.andymark.com/product-p/am-2617.htm ) Tools to make them aren't something we have. Last year, in order to connect to USDigital encoders, we cut one end off the TalonSRX data cables and in-line spliced to the cable needed for the US Digital encoder.

Switching to the VersaPlanetary Integrated Encoder, though, would let us use a stock cable at both ends. However, we haven't seen a source for these of longer than 12" in length. Is there an electrical issue with having these cables be much longer than that?

We'd like to put a VersaPlanetary with an encoder at the end of an arm which reaches outside the robot perimeter. In prior years, we would have run an encoder wire all the way back along the arm to the RIO to connect the encoder directly to the RIO via long wires. However, with the VersaPlanetary encoder that would require a very long (say 4' to 6') TalonSRX Data Cable. Alternatively, we could put the TalonSRX out on the end of the arm, but that's unattractive from a weight perspective, as well as meaning that our CANbus goes out on the arm, where if the CANbus wiring gets disturbed, the whole robot becomes a brick.

Any suggestions? Anybody know of a source for long TalonSRX Data Cables?

Thanks,
--ken

[Cecil]

I too was going to ask the very same question. Do we need to cut and splice shielded ethernet cables for running the encoder wires? How will signal degrade over this long run?

[Joe Derrick]

Ribbon Cable from Digi-Key

and

connector from Digi-Key

We ordered these using the Digi-Key KOP voucher and are hoping they will do the trick. They haven't come in yet so we can't say 100% that they will be perfect but are hoping they will allow us to keep our controllers in a nice orderly package.

[Ken Streeter]

Originally Posted by Joe Derrick

We ordered these using the Digi-Key KOP voucher and are hoping they will do the trick. They haven't come in yet so we can't say 100% that they will be perfect but are hoping they will allow us to keep our controllers in a nice orderly package.

Joe, thanks a lot for the recommendation on some specific part numbers! It's greatly appreciated.

After you receive them, we'd be interested in hearing how these work out for you and/or if you have any tips regarding their use.

[marshall]

Just going to drop these here:

https://oshpark.com/shared_projects/WtaLYuJy


http://www.digikey.com/product-detai...9-1-ND/5047559
http://www.digikey.com/product-searc...1521-00010T1LF

I make no promises.

[Ken Streeter]

Originally Posted by Joe Derrick

We ordered these using the Digi-Key KOP voucher and are hoping they will do the trick.

Just had to mention that we just ordered some of these from Digi-Key using the KOP voucher.

However, the Digi-Key representative placing our order may have been the most pleasant, personable customer service representative I have ever talked to on the phone. EVER.

In addition to taking our order efficiently and in a friendly manner, when I mentioned the FIRST robotics voucher, she said how great she thought the program was (has a friend who is a mentor), thanked me for what I was doing in mentoring students, and said she hopes the build season goes well for us!

Three cheers for Digi-Key!

[thinker&planner]

Originally Posted by Joe Derrick

connector from Digi-Key

I looked at the datasheet for that connector and it appears that the overall width (the long side of the connector) for a 10 pin connector is 14.34mm, and the datasheet from CTRE has it at 10.58mm. You will probably be able to file off the ends and get it to work though.

I believe that this connector is a lot closer, if not the same connector as the ones from CTRE or VEX. The width is 10.58mm.

We were trying to decide what to use our digikey voucher on, and now we know what we will get.

[tr6scott]

support@crosstheroadelectronics.com is your friend.

Omar will respond less than a day, and probably within seconds if it is between 8pm and 3am

[Joe Derrick]

We just received our Digi-key voucher and things behave the same as when we were running our speed control loops using a cable purchased from CTR.

We did end up using a scalpel to take off a tab on the side in order to fit it into the SRX.

Good luck!

[Ken Streeter]

Originally Posted by Joe Derrick

We just received our Digi-key voucher and things behave the same as when we were running our speed control loops using a cable purchased from CTR.

We did end up using a scalpel to take off a tab on the side in order to fit it into the SRX.

Joe, thanks for the follow-up feedback!