kopia lustrzana https://github.com/micropython/micropython
92 wiersze
3.2 KiB
ReStructuredText
92 wiersze
3.2 KiB
ReStructuredText
|
Controlling APA102 LEDs
|
||
|
|
=======================
|
||
|
|
|
||
|
|
APA102 LEDs, also known as DotStar LEDs, are individually addressable
|
||
|
|
full-colour RGB LEDs, generally in a string formation. They differ from
|
||
|
|
NeoPixels in that they require two pins to control - both a Clock and Data pin.
|
||
|
|
They can operate at a much higher data and PWM frequencies than NeoPixels and
|
||
|
|
are more suitable for persistence-of-vision effects.
|
||
|
|
|
||
|
|
To create an APA102 object do the following::
|
||
|
|
|
||
|
|
>>> import machine, apa102
|
||
|
|
>>> strip = apa102.APA102(machine.Pin(5), machine.Pin(4), 60)
|
||
|
|
|
||
|
|
This configures an 60 pixel APA102 strip with clock on GPIO5 and data on GPIO4.
|
||
|
|
You can adjust the pin numbers and the number of pixels to suit your needs.
|
||
|
|
|
||
|
|
The RGB colour data, as well as a brightness level, is sent to the APA102 in a
|
||
|
|
certain order. Usually this is ``(Red, Green, Blue, Brightness)``.
|
||
|
|
If you are using one of the newer APA102C LEDs the green and blue are swapped,
|
||
|
|
so the order is ``(Red, Blue, Green, Brightness)``.
|
||
|
|
The APA102 has more of a square lens while the APA102C has more of a round one.
|
||
|
|
If you are using a APA102C strip and would prefer to provide colours in RGB
|
||
|
|
order instead of RBG, you can customise the tuple colour order like so::
|
||
|
|
|
||
|
|
>>> strip.ORDER = (0, 2, 1, 3)
|
||
|
|
|
||
|
|
To set the colour of pixels use::
|
||
|
|
|
||
|
|
>>> strip[0] = (255, 255, 255, 31) # set to white, full brightness
|
||
|
|
>>> strip[1] = (255, 0, 0, 31) # set to red, full brightness
|
||
|
|
>>> strip[2] = (0, 255, 0, 15) # set to green, half brightness
|
||
|
|
>>> strip[3] = (0, 0, 255, 7) # set to blue, quarter brightness
|
||
|
|
|
||
|
|
Use the ``write()`` method to output the colours to the LEDs::
|
||
|
|
|
||
|
|
>>> strip.write()
|
||
|
|
|
||
|
|
Demonstration::
|
||
|
|
|
||
|
|
import time
|
||
|
|
import machine, apa102
|
||
|
|
|
||
|
|
# 1M strip with 60 LEDs
|
||
|
|
strip = apa102.APA102(machine.Pin(5), machine.Pin(4), 60)
|
||
|
|
|
||
|
|
brightness = 1 # 0 is off, 1 is dim, 31 is max
|
||
|
|
|
||
|
|
# Helper for converting 0-255 offset to a colour tuple
|
||
|
|
def wheel(offset, brightness):
|
||
|
|
# The colours are a transition r - g - b - back to r
|
||
|
|
offset = 255 - offset
|
||
|
|
if offset < 85:
|
||
|
|
return (255 - offset * 3, 0, offset * 3, brightness)
|
||
|
|
if offset < 170:
|
||
|
|
offset -= 85
|
||
|
|
return (0, offset * 3, 255 - offset * 3, brightness)
|
||
|
|
offset -= 170
|
||
|
|
return (offset * 3, 255 - offset * 3, 0, brightness)
|
||
|
|
|
||
|
|
# Demo 1: RGB RGB RGB
|
||
|
|
red = 0xff0000
|
||
|
|
green = red >> 8
|
||
|
|
blue = red >> 16
|
||
|
|
for i in range(strip.n):
|
||
|
|
colour = red >> (i % 3) * 8
|
||
|
|
strip[i] = ((colour & red) >> 16, (colour & green) >> 8, (colour & blue), brightness)
|
||
|
|
strip.write()
|
||
|
|
|
||
|
|
# Demo 2: Show all colours of the rainbow
|
||
|
|
for i in range(strip.n):
|
||
|
|
strip[i] = wheel((i * 256 // strip.n) % 255, brightness)
|
||
|
|
strip.write()
|
||
|
|
|
||
|
|
# Demo 3: Fade all pixels together through rainbow colours, offset each pixel
|
||
|
|
for r in range(5):
|
||
|
|
for n in range(256):
|
||
|
|
for i in range(strip.n):
|
||
|
|
strip[i] = wheel(((i * 256 // strip.n) + n) & 255, brightness)
|
||
|
|
strip.write()
|
||
|
|
time.sleep_ms(25)
|
||
|
|
|
||
|
|
# Demo 4: Same colour, different brightness levels
|
||
|
|
for b in range(31,-1,-1):
|
||
|
|
strip[0] = (255, 153, 0, b)
|
||
|
|
strip.write()
|
||
|
|
time.sleep_ms(250)
|
||
|
|
|
||
|
|
# End: Turn off all the LEDs
|
||
|
|
strip.fill((0, 0, 0, 0))
|
||
|
|
strip.write()
|