The NXT Duel is a game that tests your reflexes, entirely built with a NXT 2.0 kit. Play against other person, or play by yourself beating the computer challenges.

How to play

Whoever shoots first after the bell rings wins. Watch out for distractions, like the crows squawking — if you shoot too early, you’ll lose.

During the round, an orange flag will rise. Its purpose is to create tension since the bell is guaranteed to ring sometime before it fully rises.

Single player mode

In single player mode, you’ll need to beat the 9 computer challenges: after the bell rings, you must shoot within the number of milliseconds specified in the round. In the first round, you’ll have 500 ms — that’s actually plenty of time! In the last challenge, though, you’ll be at the edge of standard human reflex times 🙂

The record number of tries that you take to complete all challenges is recorded. Can you do it in only 9 rounds, without a single miss?

In this mode, use the gun with the grey handle.

Two player mode

It’s simple: whoever shoots first, wins! You can select the number of rounds you need to win in order to win the game. The response time of the round winner is shown on the screen.

Instruction and Program

First, get everything you need:

  1. Download program, source, LDD model and resources
  2. Extract the zip file (check this if you need help)

Buliding the model:

  1. If you don’t have LEGO Digital Designer, download and install it.
  2. Double click the duel.lxf file in the folder you have extracted.
  3. After the file opens in LEGO Digital Designer, press F7 and follow the instructions to build the model.

Downloading the program and files to the NXT:

  1. Turn on your NXT and connect it to your PC using the USB cable.
  2. Open the LEGO MINDSTORMS NXT sofware.
  3. Near “Create new program”, click “Go >>”.
  4. Open the NXT window (click the upper left button above the “Play” button.
  5. Click on the “memory” tab.
  6. Click “Download”. Go to folder you have extracted in Step 2, select the first file and Click OK. Click “Download” again, select the second file, click OK, and so on for all files (sorry, I don’t know any easier way to do this).
  7. In your NXT, go to “My Files”, “Software Files”, then “Duel”.
  8. Play!

The program is coded in NXC, you can use the Bricx Command Center if you want to make changes to the code.

Fun Facts About Reaction Time

There is some interesting research on reaction time; check this literature review. Some highlights:

  • Reaction time for sound stimuli is smaller than for visual stimuli; 160 ms vs 190 ms on average. (These are simple reaction times. Since there are distractions in the NXT Duel, your response time will be slower.)
  • Your reaction time get worse if you’re too relaxed or too tense.
  • Your reaction time is faster during expiration.
  • Your reaction time is faster with your left hand if you are right-handed, and vice-versa.