pxt-calliope/docs/projects/compass.md
2017-12-06 20:23:17 -08:00

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# Compass
## ~avatar avatar
Welcome! This guided tutorial will show you how to program a script that displays which direction the @boardname@ is pointing. Let's get started!
## ~
![](/static/mb/projects/a5-compass.png)
Display the direction that the @boardname@ is facing using the compass.
## 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` or greater than `315`,
then the compass heading is mostly pointing toward **North**. Display `N` on the @boardname@.
```blocks
basic.forever(() => {
let degrees = input.compassHeading();
if (degrees < 45 || degrees > 315) {
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 || degrees > 315) {
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 || degrees > 315) {
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 || degrees > 315) {
basic.showString("N");
}
else if (degrees < 135) {
basic.showString("E");
}
else if (degrees < 225) {
basic.showString("S");
}
else {
basic.showString("W");
}
});
```