This lesson uses the @boardname@ to measure the reaction time of a student by completing a circuit on a board. The student will be measuring his/her reaction time in an undistracted environment and a distracted environment.
Connect each piece of foil to the appropriate pin on the @boardname@.
Test the apparatus by putting one hand on the ground pin and one hand on the ``P0`` pin. This will complete the circuit and start the timer on the @boardname@ after a 3 second count down.
Once the timer starts, wait for the LED screen to light up and then press the Ground foil with one hand and and the ``P1`` with the other. This will connect the circuit and shut off the timer.
In order for **Reaction Time** to follow the rules for determining the player's reaction speed, we need to add variables that will store data. Then we will assign (set) the value of the variables. We want to name the four (4) variables as follows: “start”, “end”, “false_start”, and “running”. Set the value of the variables, “start” and “end” to 0. Then set the value of the variable “false_start” and “running” to false. Modify your code so that your code looks like this.
We want to register an event handler that will execute whenever the user holds the GND pin with one hand, and presses pin 0 or pin with the other hand, thus completing a circuit. When you run a script with this function in a web browser, click pins 0 or 1 in the simulator. The game will start on ``P0`` and the ``P1`` will detect when the player visualizes a single LED on the screen. Modify your code so that your code looks like this.
We want to code the countdown timer that will be displayed on pin pressed 0. We will insert three show number blocks to visually display the countdown: ``3 2 1``. Then we want to add a ``|basic|`` block clear screen to clear the numbers from the screen. Modify your code so that your code looks like this:
We want to set variables, running and set false start to false. This occurs on pin 0 pressed. Those blocks represent the true and false Boolean values. A Boolean has one of two possible values: true; false.
Modify your code so that your code looks like this:
We want to introduce the reaction time experiment if there is not a false start on pin 0 pressed. Reaction time will randomly plot a LED on the x and y coordinates. Modify your code so that your code looks like this:
We want to introduce the reaction time experiment if there is not a false start. Reaction time will randomly plot a LED on the x and y coordinates. Modify your code so that your code looks like this:
We want to add code to detect when the player presses the Ground foil with one hand and and the P1 with the other. This code will connect the circuit and shut off the timer. We will add code to have the @boardname@ read off the time in milliseconds from when the timer starts and the circuit is completed. This code also detects if there is a correct reaction or false start on pin 1 pressed.
We want to display one of two images on pin 1 pressed. The first image displays if the player correctly completes the circuit between GND and P1. A correct reaction occurs to complete the circuit on pin 1 pressed after the randomly generated LED appears on the screen. The seconde image displays if the player completes a circuit between GND and P1 on a false start. A false start occurs when the player completes a circuit on pin 1 pressed before the LED randomly appears on the x, y coordinates. Modify your code so that your code looks like this:
```blocks
let start = 0
let end = 0
let false_start = false
let running = false
input.onPinPressed(TouchPin.P1, () => {
if (running) {
running = false
end = input.runningTime()
basic.showLeds(`
# # . . .
# # . . .
# # . . .
# # . . .
# # . . .
`)
basic.pause(1000)
basic.showNumber(end - start)
} else {
false_start = true
basic.showLeds(`
. . . . .
# . # . .
. # . . .
# . # . .
. . . . .
`)
}
})
input.onPinPressed(TouchPin.P0, () => {
basic.showNumber(3)
basic.showNumber(2)
basic.showNumber(1)
basic.clearScreen()
running = false
false_start = false
basic.pause(1000 + Math.random(2000))
if (!(false_start)) {
start = input.runningTime()
running = true
led.stopAnimation()
basic.clearScreen()
led.plot(Math.random(5), Math.random(5))
}
})
running = false
false_start = false
end = 0
start = 0
```
## Extension
After the students have finished their experiments. Have them play the game with a friend (using the P2 pin) and have competitons to see who is the quickest on the draw.
