neopixelRainbow.py

#!/usr/bin/python3
# ////////////////////////////////////////
# //	neopixelRainbow.py
# //	UDisplays a moving rainbow pattern on the NeoPixels
# //	Usage:	Run neopixelRpmsg.c on the PRU, Run neopixelRainbow.py on the ARM
# //	Wiring:	The NeoPixel Data In goes to P9_14, the plus lead to P9_3 or P9_4
# //			and the ground to P9_1 or P9_2.  If you have more then 40 some 
# //			NeoPixels you will need and external supply.
# //	Setup:	Run neopixelRpmsg.c on the PRU
# //	See:	 
# //	PRU:	Runs on ARM
# ////////////////////////////////////////
from time import sleep
import math

len = 24
amp = 12
f = 26
shift = 3
phase = 0

# Open a file
fo = open("/dev/rpmsg_pru30", "wb", buffering=False)  # Write binary unbuffered

while True:
    for i in range(0, len):
        r = (amp * (math.sin(2*math.pi*f*(i-phase-0*shift)/len) + 1)) + 1;
        g = (amp * (math.sin(2*math.pi*f*(i-phase-1*shift)/len) + 1)) + 1;
        b = (amp * (math.sin(2*math.pi*f*(i-phase-2*shift)/len) + 1)) + 1;
        fo.write("%d %d %d %d\n".encode("utf-8") % (i, r, g, b))
        # print("0 0 127 %d" % (i))

    fo.write("-1 0 0 0\n".encode("utf-8"));
    phase = phase + 1
    sleep(0.1)

# Close opened file
fo.close()