pxt-calliope/docs/projects/compass.md
2016-11-01 17:44:37 -07:00

106 lines
2.0 KiB
Markdown

# compass
![](/static/mb/projects/a5-compass.png)
Display the direction that the @boardname@ is facing using the compass
### ~avatar avatar
Welcome! This guided tutorial will show you how to program a script that displays the direction the @boardname@ is pointing. Let's get started!
### ~
## Step 1
Create a loop that will continuously update the reading of the compass.
```blocks
basic.forever(() => {
})
```
## Step 2
Store the reading of the @boardname@ in a variable called `degrees`.
```blocks
basic.forever(() => {
let degrees = input.compassHeading()
})
```
## Step 3
If `degrees` is less than `45`, then the compass heading is mostly pointing toward North. Display `N` on the @boardname@.
```blocks
basic.forever(() => {
let degrees = input.compassHeading();
if (degrees < 45) {
basic.showString("N");
}
});
```
## Step 4
If `degrees` is less than 135, the @boardname@ is mostly pointing East. Display `E` on the @boardname@.
```blocks
basic.forever(() => {
let degrees = input.compassHeading();
if (degrees < 45) {
basic.showString("N");
}
else if (degrees < 135) {
basic.showString("E");
}
});
```
## Step 5
If `degrees` is less than 225, the @boardname@ is mostly pointing South. Display `S` on the @boardname@.
```blocks
basic.forever(() => {
let degrees = input.compassHeading();
if (degrees < 45) {
basic.showString("N");
}
else if (degrees < 135) {
basic.showString("E");
}
else if (degrees < 225) {
basic.showString("S");
}
});
```
## Step 6
If none of these conditions returned true, then the @boardname@ must be pointing West. Display `W` on the @boardname@.
```blocks
basic.forever(() => {
let degrees = input.compassHeading();
if (degrees < 45) {
basic.showString("N");
}
else if (degrees < 135) {
basic.showString("E");
}
else if (degrees < 225) {
basic.showString("S");
}
else {
basic.showString("W");
}
});
```