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RASP-SENSE-HAT-ASTRO-PI-Débuter (voir la source)
Version du 24 août 2015 à 21:12
, 24 août 2015 à 21:12→Afficher du Texte
| back_colour ||The back_colour parameter alters the colour of the background and works in the same way as the text_colour
| back_colour ||The back_colour parameter alters the colour of the background and works in the same way as the text_colour
|}
|}
So this program would display the text {{fname|Astro Pi is awesome!!}} more slowly, with the text in yellow '''[255,255,0]''' and the background in blue '''[0,0,255]''':
<nowiki>from astro_pi import AstroPi
ap = AstroPi()
ap.show_message("Astro Pi is awesome!!", scroll_speed=0.05, text_colour=[255,255,0], back_colour=[0,0,255])</nowiki>
You could also make the message repeat using a while loop like this:
<nowiki>from astro_pi import AstroPi
ap = AstroPi()
while True:
ap.show_message("Astro Pi is awesome!!", scroll_speed=0.05, text_colour=[255,255,0], back_colour=[0,0,255])</nowiki>
'''2.''' Click File -- Save As, give your program a name e.g. {{fname|loop_text.py}}, then press F5 to run.
'''3.''' The LED matrix can also display a single character, rather than an entire message, using the {{fname|ap.show_letter}} function which also has some optional '''parameters'''.
{| class="wikitable"
| align="center" style="background:#f0f0f0;"|'''Parameter'''
| align="center" style="background:#f0f0f0;"|'''Effect'''
|-
| scroll_speed ||The scroll_speed parameter affects how quickly the text moves on the screen. The default value is 0.1. The bigger the number, the slower the speed
|-
| text_colour ||The text_colour parameter alters the colour of the text and is specified as 3 values for Red, Green, Blue. Each value can be between 0 - 255, so [255,0,255] would be Red + Blue = Purple
|-
| back_colour ||The back_colour parameter alters the colour of the background and is specified as 3 values for Red, Green, Blue. Each value can be between 0 - 255, so [255,0,255] would be Red + Blue = Purple
|}
So this program would display a single Red "J":
<nowiki>from astro_pi import AstroPi
ap = AstroPi()
ap.show_letter("J",text_colour=[255, 0, 0])</nowiki>
And this program would add the '''sleep function''' to display letters separated by a brief pause:
<nowiki>from astro_pi import AstroPi
import time
ap = AstroPi()
ap.show_letter("O",text_colour=[255, 0, 0])
time.sleep(1)
ap.show_letter("M",text_colour=[0, 0, 255])
time.sleep(1)
ap.show_letter("G",text_colour=[0, 255, 0])
time.sleep(1)
ap.show_letter("!",text_colour=[0, 0, 0], back_colour=[255, 255, 255])
time.sleep(1)
ap.clear()</nowiki>
Click '''File -- Save As''', give your program a name eg {{fname|omg.py}}, then press '''F5''' to run.
For added interest you could use a random number generator to choose a number between 0 and 255 for the colours:
<nowiki>from astro_pi import AstroPi
import time
import random
ap = AstroPi()
r = random.randint(0,255)
ap.show_letter("O",text_colour=[r, 0, 0])
time.sleep(1)
r = random.randint(0,255)
ap.show_letter("M",text_colour=[0, 0, r])
time.sleep(1)
r = random.randint(0,255)
ap.show_letter("G",text_colour=[0, r, 0])
time.sleep(1)
ap.show_letter("!", text_colour=[0, 0, 0], back_colour=[255, 255, 255])
time.sleep(1)
ap.clear()</nowiki>
Click '''File -- Save As''', give your program a name eg {{fname|random_omg.py}}, then press '''F5''' to run.
In both these programs the {{fname|ap.clear()}} method has been used at the end to clear the matrix.
=== Ideas ===
* Could you use the ideas used so far to tell a joke via the LED screen?
* All the examples so far could be made shorter, while still achieving the same thing. Can you find ways to make these shorter and more efficient?
* How would you choose a totally random colour, rather than just a random shade of a colour?
* If your Astro Pi is connected to the internet you could use a Twitter library to make it display incoming tweets!
== Afficher des images ==
The LED matrix can display more than just text! We can control each LED individually to create an image. We can accomplish this in a couple of ways.
'''1.''' The first approach is to set pixels (LEDs) individually; we can do this using the {{fname|ap.set_pixel()}} method. First, we need to be clear about how we describe each pixel.
The Astro Pi board uses a coordinate system like the one shown below; crucially the numbering begins at '''0''', not 1. Also, the origin is in the '''top left''' rather than the bottom left as you may be used to.
[[Fichier:RASP-SENSE-HAT-ASTRO-PI-Debuter-20.png]]
* the blue pixel is at coordinates (0, 2)
* the red pixel is at coordinates (7, 4)
{{RASP-SENSE-HAT-ASTRO-PI-TRAILER}}
{{RASP-SENSE-HAT-ASTRO-PI-TRAILER}}