Reaction Tester

Did you ever want to know how fast your reflexes were?

This little device can measure how quickly you can react to a 'beep'.

Here's how it works:
- Turn on the NXT and press the button
- A random length of time (1-5 seconds) elapses and then a short 'beep' is played
- You need to clap your hands as soon as you hear the beep
- The time between when the 'beep' is played and when the clap is heard is recorded
- This time is then converted into an angle (0 seconds = 0 degrees, 0.9 seconds = 180 degrees)
- This angle is sent to the motor, which pauses for 2 seconds before returning back to the start.
- If you take too long (more than 0.9 seconds, the device makes an error sound and no time is displayed)

Damien Kee


Dave Parker said…
Very nice! When I was in High School way back when, taking driver taining, they brought in a reaction tester, which was an expensive specialized thing, to show us all how long it took to hit the brakes after you see the lights in front of you. This a great example of using the NXT to get the point across much less expensively!
AlexD said…
I assume you placed anti-cheating measures, to avoid immediate trigger if a person is, say, yelling all the time. Also, reading the sound sensor (and other I2C sensors) for the first time in a program takes longer (up to 1/3 second) which can bias the first reading (or all readings if the program is restarted every time). An empty read at the beginning of the program fixes that.
Damien Kee said…

No anti-cheating measure in place, it was just something I threw together quickly after an idea.

Kids would cheat... would they??.... never! :)
AlexD said…
Well, think of it as setting rules. Kids will notice that the fastest time correlates with constant loud noise, and if the only goal is to get the fastest time, then they will do what is necessary. Not cheating really, just playing by accidental rules.

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