14

Having learned that Mindstorms EV3 doesn't work directly with Power Functions,

Q: Can you use Power Functions motors with the EV3 programmable brick?

A: No, the connector does not match.

I still wonder what could be possible workarounds to use them together?

6

You can accomplish this with these two parts:

10

As mentioned by @guestguy123 and @eficker, it is easy to combine an EV3 cable and a PF cable to make a custom cable that allows the EV3 to control. This can even be done without soldering - I just twist the wires together and tape them with electrical tape. The full schematic is here: Schematic for cable

All you need is 2 resistors (1x1kOhm and 1x10kOhm) which are cheap to get at your local electronics store (e.g. Radioshack or Maplin's) and the willpower to cut through 2 good Lego wires (1 PF cable and 1 EV3 cable). But once you do, it recognizes a PF motor as an NXT style unregulated motor and you can send it commands.

  • forgot to mention that I snipped that image from the youtube video - not my work ;) – Phil B. Nov 21 '14 at 2:38
  • Do the resistors avoid the timeout problem mentioned in David Lechners answer? – Peter Green Jan 5 '18 at 16:44
  • I have used my modified cables regularly and never encountered that problem, so I think the answer to your question is Yes. – Phil B. Jan 5 '18 at 21:19
4

You can use 3rd party modules:

Or third party cable NXT to PF Cable (however I am not 100% sure if it will work with EV3). Accoring to answer on lejos forum it should work with Lejos RCXMotor class.

2

You can connect the Power Functions motor to the EV3 with a LEGO 8528 cable and a LEGO 8886 cable.

LEGO 8528 cable

LEGO 8886 cable

In addition to the cables, you need to know how to trick the software. You can use the unregulated motor block, but it will stop after a short time (1 second or so). You have to constantly change the speed to keep the motor powered.

Here is a simple example to run the motor at 75% of full power:

Unregulated motor loop

Using a single unregulated motor in a block like this won't work because the power value does not change. It seems that changing the power value is what resets the timeout on the EV3.

1

this explains how to make a conversion cable:

http://www.youtube.com/watch?v=Ns3TODgRlCE

You take a cable from the EV3 and a power functions cable, add some resistors and solder it up. Not a tough mod, but you do have to sacrifice two cables to the cause. Although, the possibilities are worth it imo, as you can now control a lego train or other power functions sets with EV3.

  • 2
    Can add details (in your answer) about how this cable is made before referring to this external link? – pcantin Mar 9 '14 at 15:00

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