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pi_pico_neopixel
kopia lustrzana https://github.com/blaz-r/pi_pico_neopixel
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Max Carlson 2024-02-07 16:47:32 +02:00
rodzic 16026e5d88
commit a145677e59
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neopixel.py
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@ -3,45 +3,29 @@ from machine import Pin
import rp2
# PIO state machine for RGB. Pulls 24 bits (rgb -> 3 * 8bit) automatically
@rp2.asm_pio(sideset_init=rp2.PIO.OUT_LOW, out_shiftdir=rp2.PIO.SHIFT_LEFT, autopull=True, pull_thresh=24)
def ws2812():
T1 = 2
T2 = 5
T3 = 3
wrap_target()
label("bitloop")
out(x, 1) .side(0) [T3 - 1]
jmp(not_x, "do_zero") .side(1) [T1 - 1]
jmp("bitloop") .side(1) [T2 - 1]
label("do_zero")
nop() .side(0) [T2 - 1]
wrap()
# PIO state machine for RGBW. Pulls 32 bits (rgbw -> 4 * 8bit) automatically
# based on https://learn.adafruit.com/intro-to-rp2040-pio-with-circuitpython/advanced-using-pio-to-drive-neopixels-in-the-background by https://learn.adafruit.com/u/jepler
@rp2.asm_pio(sideset_init=rp2.PIO.OUT_LOW, out_shiftdir=rp2.PIO.SHIFT_LEFT, autopull=False, pull_thresh=32)
def sk6812():
wrap_target()
pull(block) .side(0)
out(y, 32) .side(0)
pull(block) .side(0) # get fresh NeoPixel bit count value
out(y, 32) .side(0) # get count of NeoPixel bits
label("bitloop")
pull(ifempty) .side(0)
pull(ifempty) .side(0) # drive low
out(x, 1) .side(0) [5]
jmp(not_x, "do_zero") .side(1) [3]
jmp(y_dec, "bitloop") .side(1) [4]
jmp("end_sequence") .side(0)
jmp(not_x, "do_zero") .side(1) [3] # drive high and branch depending on bit val
jmp(y_dec, "bitloop") .side(1) [4] # drive high for a one (long pulse)
jmp("end_sequence") .side(0) # sequence is over
label("do_zero")
jmp(y_dec, "bitloop") .side(0) [4]
jmp(y_dec, "bitloop") .side(0) [4] # drive low for a zero (short pulse)
label("end_sequence")
pull(block) .side(0)
out(y, 32) .side(0)
pull(block) .side(0) # get fresh delay value
out(y, 32) .side(0) # get delay count
label("wait_reset")
jmp(y_dec, "wait_reset") .side(0)
jmp(y_dec, "wait_reset") .side(0) # wait until delay elapses
wrap()
@ -107,7 +91,7 @@ class Neopixel:
(mode.index('B') ^ 3) * 8, (mode.index('W') ^ 3) * 8)
bpp = 4
else:
self.sm = rp2.StateMachine(state_machine, ws2812, freq=12_800_000, sideset_base=Pin(pin))
self.sm = rp2.StateMachine(state_machine, sk6812, freq=12_800_000, sideset_base=Pin(pin))
self.shift = (((mode.index('R') ^ 3) - 1) * 8, ((mode.index('G') ^ 3) - 1) * 8,
((mode.index('B') ^ 3) - 1) * 8, 0)
self.sm.active(1)
@ -115,10 +99,13 @@ class Neopixel:
self.delay = delay
self.brightnessvalue = 255
# from https://learn.adafruit.com/intro-to-rp2040-pio-with-circuitpython/advanced-using-pio-to-drive-neopixels-in-the-background
byte_count = bpp * num_leds
bit_count = byte_count * 8
padding_count = -byte_count % 4
# send number of bits to read
self.header = bytearray(struct.pack("L", bit_count - 1))
# pad if needed, then send number of cycles to delay
self.trailer = bytearray(b"\0" * padding_count + struct.pack("L", 3840))