c_meyer/pxt-calliope
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Rewrote in simple language.

Browse Source
This commit is contained in:
Ron Hale-Evans 2016-06-13 15:47:08 -07:00
parent de293be4fc
commit 23c4087830
1 changed files with 19 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
docs/reference/led/point.md
View File

@ -1,6 +1,7 @@
# Point
Get the on/off state of a LED on the [LED screen](/device/screen). Specify the LED using x, y coordinates.
Find whether the LED you say on the
[LED screen](/device/screen) is on or off.
```sig
led.point(0,0);
@ -8,30 +9,36 @@ led.point(0,0);
### Parameters
* x - [Number](/reference/types/number); the *x coordinate* or horizontal position (0, 1, 2, 3, 4)
* y - [Number](/reference/types/number); the *y coordinate* or vertical position (0, 1, 2, 3, 4)
* **x** is a [number](/reference/types/number) that means the horizontal spot on the LED screen (from left to right: 0, 1, 2, 3, or 4)
* **y** is a [number](/reference/types/number) that means the vertical spot on the LED screen (from top to bottom: 0, 1, 2, 3, or 4)
If a parameter is [out of bounds](/reference/out-of-bounds) (a value other than 0-4), then this function will return `false`.
If a parameter is [out of bounds](/reference/out-of-bounds) (a value
other than 0 to 4), this function will return `false`.
### Returns
* [Boolean](/reference/types/boolean) - `true` if the LED is *on* and `false` if the LED is *off*
* a [boolean](/reference/types/boolean). If it is `true`, that means the LED is on. If it is `false`, that means the LED is off.
### x, y coordinates?
### ~hint
The LED screen is made up of 25 LEDs arranged in a 5x5 grid. To figure out the ``x``, ``y`` coordinates, see [LED screen](/device/screen).
The LED screen is a solid square of LEDs with five LEDs on each side.
To learn more about how you number the LEDs with ``x`` and ``y``
coordinates, see [LED screen](/device/screen).
### Example: toggle off
### ~
If `point(1, 1)` returns `true`, then the following code turns off the LED:
### Example: Toggle off
This program turns the center LED (2, 2) off if it is already on. (If
it is already off, this program leaves it off.)
```blocks
if (led.point(1, 1)) {
led.unplot(1, 1)
if (led.point(2, 2)) {
led.unplot(2, 2)
}
```
### See also
[unplot](/reference/led/unplot), [plot](/reference/led/plot), [LED screen](/device/screen), [create image](/reference/images/create-image)
[unplot](/reference/led/unplot), [plot](/reference/led/plot), [LED screen](/device/screen)