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1. The LeftoverBot Control System


We’ve build a control system is made mostly out of recycled electronics from the Cascade Effect season along with a Modern Robotics Core Legacy Module from the 2015 control system. The nice thing about this is that you don’t need a Modern Robotics Core Power Distribution Module.  In our case, we didn’t have to purchase anything, and we are able to build several small robots to let kids get hands-on experience playing with them.

Note that this is just meant to run a basic drivetrain for demonstration robots, and isn’t a legal FTC robot configuration! We just wanted to share a trick we used to save us a lot of money on controls.

To make the system work, you need:

  • 1 Core Legacy Module
  • 1 or more Hitechnic Motor Controllers
  • 2 or more Tetrix or AndyMark Neverest motors
  • 1 12 Volt battery
  • 1 USB micro-to-mini cable
  • 1 or more Lego Mindstorm cable

You will also need the motor cables and power cables to connect everything to power.  If you have more than one motor controller or a servo controller then you will also need some sort of power splitter (we use an Anderson Powerpole splitter from our 2015 robots).

The Core Legacy Module is powered by the USB on the phone, while everything else is powered by the 12 Volt battery.


Here, we have connected the entire system together.

The phone plugs directly into the Legacy Control Module. From there, we attach one of the Lego cables to the Hitechnic motor controller.

We connect the battery directly to the battery inputs in the motor controller. We’ll also connect the motors to the controller in their labeled ports.

We spoke with the Modern Electronics engineers at FIRST Championships, and they don’t recommend running any sensors off of the legacy module when it is just powered by the phone itself, because it will probably drain the battery very quickly.

At this point, you are ready to go!