Connecting the KOP Line Sensor

I’m working on getting the KOP Line Sensors working on my team’s robot. It seems to me, based on what I’ve seen on the forum, that it should be connected to the Digital Sidecar in the Digital I/O section. I understand which wires should go where. My question is, what sort of adapter can I use to connect the wires of the sensor to the pins of the sidecar?

You really have two choices:

  1. Cut a standard PWM cable in half, and solder the signal wire you wish to use to the white lead on the PWM cable. Plug into the digital side car as you normally would.
  2. Terminate the signal wire into a 0.100" pitch molex connector, just make sure you get it in the correct position for connection on the DSC. We’ve used these before, and they work amazingly well - it’s essentially like making your own PWM cables. We’ve also used several others in the product series on the robot before - the single row, 5 circuit for encoder input into the Jaguars, the dual row, 4 circuit for limit switch input into the Jaguars, etc.

Cut a PWM cable in half and splice the signal wire from the sensor (either black or white) to the signal wire going to the Digital Sidecar (white).

If you’re not comfortable splicing wires, use the terminal strip from the Kit of Parts. Screw the incoming wire to one side, and the outgoing wire to the other side.

Make sure you connect power to the sensor properly. The power wire (brown) goes to the red side of a 20 amp circuit from the Power Distribution board, and the common wire (blue) goes to the associated black side. Again, splice appropriately-sized power wires to the sensor wires (or use the terminal strip), because the large Wago connectors aren’t designed for the small gauge wire of the sensor.

Are we going to have any problems because the sensor out put is at 12 Volts? These are 12 Volt input and 12 Volt output…

Should we reduce voltage on the line back into the Digital Sidecar? Or is it ok because the amperage is so low?


No need to reduce the voltage. See this exhaustive discussion.

The signal lines are not 12v. They are just simple switches. Connecting them to the 5v signal line on a DIO puts 5v through them if the switch is closed, nothing of course if the switch is open.

12v only powers the sensor itself. It isn’t connected to the signal line at all.

After reading all this, I’m still having a problem with even turning the sensors on. I have the white connected to the white on a PWM, black not connected, blue to black on PWM, and brown to red. Two sensors are wired this way, plugged into DIO1 and DIO2 (I even triple-checked the orientation!). The power is plugged into the sidecar and everything. For reasons unbeknown to me, after I did this, the signal light stopped working (I tried a different DSC, too, with no positive results) and the sensors don’t turn on. I’m getting a voltage in the power plug (checked w/ a volt meter) and the motors still run, but no sensors, and, now, no signal light. Help?!?!

Your white signal connection is okay, but that’s about it. It is likely that you are loading the 5 volt output of the Digital Sidecar hard enough to shut it down. Disconnect everything and start over.

Brown is the power input. It goes to a red Wago connector 12 volt output from the Power Distribution, with a 20 A breaker.

Blue is the common. It goes to the black Wago connector next to the one providing power.

White is signal. Black is another signal. Either one goes to the signal input on one of the Digital Sidecar DIO connectors. On a standard PWM cable, that is a white wire. There is no connection to the power (red) or common (black) of the DIO connector.

Note that there is only one wire connected from the sensor to the Digital Sidecar. Power comes from the big Power Distribution block.

OH!!! Duh. Thank you!