Question about VersaPlanetary Integrated Encoder

[slhs]

We want to use the VersaPlanetary Integrated Encoder but we do not want to buy Talons for it to connect directly to. Can we connect the Encoder to the Talon SRX Encoder Breakout Board and then solder the necessary wires to that? From there the wires would connect into the roboRIO like any other encoder. I know that the board is typically used in the opposite way (connecting encoders to the Talon). I don't really see anything that wouldn't allow for this, but just want to make sure.

[Greg Needel]

Originally Posted by slhs

We want to use the VersaPlanetary Integrated Encoder but we do not want to buy Talons for it to connect directly to. Can we connect the Encoder to the Talon SRX Encoder Breakout Board and then solder the necessary wires to that? From there the wires would connect into the roboRIO like any other encoder. I know that the board is typically used in the opposite way (connecting encoders to the Talon). I don't really see anything that wouldn't allow for this, but just want to make sure.

Yes this works. The cheapest way to do this is to buy the cable (which is sold separately, but should have be included in the box) cut it and do an inline splice, so you get 2 splices for each cable. If you splice them to PWM cables, you will need to use 2 Digital ports per encoder. Check out the pinout guide on the users manual to make the correct connections.


I also assume there is a way to solder directly to the board, but the 4 exposed pads are not what I expected, and didn't want to fish around on the board since we already had some cables.

[slhs]

Originally Posted by Greg Needel

The cheapest way to do this is to buy the cable (which is sold separately, but should have be included in the box) cut it and do an inline splice, so you get 2 splices for each cable. If you splice them to PWM cables, you will need to use 2 Digital ports per encoder.

Oh yea, that's even a better idea. Thanks.

[slhs]

So I see the pinout guide in the user manual, but how are we suppose to figure out which wire is which? Will we be able to tell which wire in the data cable is connected to each pin easily? Or maybe should we just use a multimeter and check for continuity between the pin we want and each wire to figure out which is the correct one?

[ozrien]

Hey slhs,

So you have a few options...

[1] If you haven't already, leverage the free VEX voucher for 2 Talon SRXs. If you choose Talons you will get 2 for FREE. This also means leveraging the closed-loop features of the Talon since the Talon directly supports this sensor (absolute and relative). You can also read the sensor data from the roboRIO over CAN Bus since the Talon forwards everything to the RIO.
http://www.vexrobotics.com/pdv-2016.html

[2] You can use a CTRE Quadrature breakout in reverse.
http://www.ctr-electronics.com/talon...out-board.html
Normally this is used to connect a quad encoder's QuadA/B/Power/Ground to a Talon, but it can be used this way...
Mag encoder ----- ribbon cable--- breakout --- solder wires to the roboRIO.
Just wire QuadA, QuadB, 5V, and ground as you normally would on the RIO side.
The Mag encoder needs 5V, which you can get from a VRM or from the roboRIO.

[3] Using this breakout and solder wires.
http://www.ctr-electronics.com/breakoutmodule.html
The Talon SRX User's Guide and Mag Encoder User's Guide has pinout information for quadrature and power (below).

Also wiring the Magnetic Encoder to the roboRIO means you lose the ability to track the absolute position (within one rotation). In other words, you are only measuring the quadrature interface of the sensor. But as explained in Mag Encoder's User's Guide - section 5.3 - first paragraph - you can use the sensor as a simple 1024CPR encoder on anything that can decode quadrature, including the RIO.

Section 1.3 in the Mag Encoder's User's Guide has the pinout on the magencoder side.
Section 1.4.3 in the Talon's SRX User's Guide also has pinout wiring for a quadrature sensor. This is effectively the pinout you are looking for (QuadA,QuadB,5V and ground are the same pins on both sides of the ribbon cable). Make sense?

If you want to use the limit switch contacts on the Mag encoder, consider also wiring out pins 4/8 for the forward/reverse limit switches.

Look at section 1.4.1 in the Talon's User's Guide to check the connector's orientation to pin1 (ribbon connector is keyed the same on the breakouts so it's helpful).