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View Full Version : Talon SRX Breakout Board with Hall Effect Encoders


rsync
22-09-2016, 15:46
We're trying to use the Talon SRX breakout board (http://www.andymark.com/product-p/am-3281.htm) with the Talon SRX controllers and the PG71 motor. The motor comes with hall effect encoder (am-2816a) attached to the back. We connected encoder pins on the breakout board to the encoder, but are unable to read any encoder values. When printing the values in SmartDashboard, they always stay 0. We're not sure if it's a wiring issue or programming issue.

Here's some pictures for how we're connecting:
https://goo.gl/photos/6gmekW3FFhZBhXi56 (pins on breakout board)
https://goo.gl/photos/XQJWmhJqSngsGHaw5 (encoder)

Wiring question:
The breakout board has 5 pins for encoder (Ch B, V+, Ch A, IDX, V-), whereas the encoder has 4 pins (Ch B, Ch A, VCC, GND). How should those be connected?
http://files.andymark.com/Images/am-3281_SRX_InfoSheet.jpg

Programming question:
We wrote a simple program with 2 CANTalon objects, and one motor following the other. We didn't yet set the PID values, hoping to just test with the encoder values. But we were not getting any values from the encoder. The code is here: https://github.com/FRC4913/Chell/blob/new-arm/src/org/usfirst/frc/team4913/robot/Arm.java

(x-posted to programming)

JR0405
22-09-2016, 15:58
I believe your wiring is wrong, you have V+ going to pin one, V- to two, A to three, and B to four when it should be B to one, V+ to pin two, A to three, skip pin 4, and V- to pin 5.

rsync
22-09-2016, 17:15
This is how connected them:

Breakout Board ------- Encoder (pins from right)
Pin 1 (CH B) ------- Pin 4 (CH B)
Pin 2 (V+) ------- Pin 1 (VCC)
Pin 3 (CH A) ------- Pin 3 (CH A)
Pin 4 (Index) ------- Pin 2 (GND)
Pin 5 (V-) ------- Not connected

The pin labels on the encoder are not easy to see but here's the andymark page (http://www.andymark.com/product-p/am-2816a.htm).

We also tried leaving the Pin 2 (GND) of encoder out, but that didn't change anything.

JR0405
22-09-2016, 20:32
Have you tried connecting GND to V-?

marshall
22-09-2016, 21:22
This is how connected them:

Breakout Board ------- Encoder (pins from right)
Pin 1 (CH B) ------- Pin 4 (CH B)
Pin 2 (V+) ------- Pin 1 (VCC)
Pin 3 (CH A) ------- Pin 3 (CH A)
Pin 4 (Index) ------- Pin 2 (GND)
Pin 5 (V-) ------- Not connected

The pin labels on the encoder are not easy to see but here's the andymark page (http://www.andymark.com/product-p/am-2816a.htm).

We also tried leaving the Pin 2 (GND) of encoder out, but that didn't change anything.

This is not going to work. Leave the Index floating and connect GND to V-.

rsync
22-09-2016, 23:34
Thank you, that worked.

marshall
23-09-2016, 08:10
Thank you, that worked.

You're welcome! Happy to help!