tutorial5.md

let counting = false
let step = 0
input.onButtonPressed(Button.A, function () {
    counting = true
})
input.onButtonPressed(Button.B, function () {
    counting = false
})
input.onGesture(Gesture.Shake, function () {
    if (counting) {
        step += 1
    }
})
basic.forever(function () {
    basic.showNumber(step)
})

ProjectSMART Pedometer Tutorial -- Level 5

Learning about Rate

Step 1

On your screen you see the physical activity sensor we built in the last tutorial. In this tutorial, we will add a new feature that calculates your step rate.

Step 2

The ||moveSMART:runningTimeSec|| block shows the number of seconds elapsed since the @boardname@ was turned on. So if we compare the ||moveSMART:runningTimeSec|| when button A is pressed and the ||moveSMART:runningTimeSec|| when button B is pressed, we can know how much time passed between these two buttons are pushed.

Step 3

We want to know what time button A is pushed, and what time button B is pushed. So let's create two variables: ||variables: startTime|| and ||variables: endTime||. When button A is pushed, we want to store the value of ||moveSMART:runningTimeSec|| in the variable ||variables: startTime||.

For example, if you press button A five seconds after turning on the @boardname@, then ||moveSMART:runningTimeSec|| will be 5.

input.onButtonPressed(Button.A, function () {
    counting = true
    startTime = moveSMART.runningTimeSec()
})

Step 4

Next, when button B is pushed, we want to store the value of ||input:runningTime (ms)|| in the variable ||variables: endTime||.

For example, if you press button B nine seconds after turning on the @boardname@, then ||moveSMART:runningTimeSec|| will be 9.

input.onButtonPressed(Button.B, function () {
    counting = false
    endTime = input.runningTime()
})

Step 5

Next, let's get the number of seconds between pressing button A and button B. How do we get the number of seconds elapsed with your ||variables: startTime|| and ||variables: endTime|| variables?

We can get it by subtracting ||variables: endTime|| with ||variables: startTime||, and store it in a new variable called ||variables: totalTime||.

totalTime = endTime - startTime

Ignore the ||basic:on start|| block.

Step 6

Can you figure out where to put the ||variables:set totalTime to endTime - startTime|| block?

input.onButtonPressed(Button.B, function () {
    counting = false
    endTime = moveSMART.runningTimeSec()
    totalTime = endTime - startTime
})

Step 7

Now we have the number of seconds stored in ||variables: totalTime||. We can divide the number of steps by ||variables: totalTime||, and we'll get the number of steps per second. Then we can just multiply it by 60 to get the number of steps per minute, which is your step rate.

Step 8

Let's do this math when you press button B. First, create another variable, and call it ||variables: rate||.

In the ||math: math|| tray you will find blocks for subtraction and division. You can use them to set ||variables: rate||'s value.

input.onButtonPressed(Button.B, function () {
    counting = false
    endTime = moveSMART.runningTimeSec()
    totalTime = endTime - startTime
    rate = step / totalTime * 60
})

Step 9

Let's also restart your step count when you press button B, so that when you press on button A the next time, you can get a new step count and a new rate.

input.onButtonPressed(Button.B, function () {
    counting = false
    endTime = moveSMART.runningTimeSec()
    totalTime = endTime - startTime
    rate = step / totalTime * 60
    step = 0
})

Step 10

Finally, let's show the rate on the @boardname@. So instead of showing the number of steps at all time, let's show ||variables: rate|| when we're not counting.

Do you remember what the ||logic: if...then...else|| block does? Can you figure out what to do?

Hint: look in the ||logic: logic|| tray.

basic.forever(function () {
    if (counting) {
        basic.showNumber(step)
    } else {
        basic.showNumber(rate)
    }
})

Step 11

Now we have a physical activity sensor that also shows your step rate! You can now flash your code into your real @boardname@.

Press the |Download| on the bottom left of your screen. You should see the lights on your real @boardname@ flashing.