set_status_leds.py

#!/usr/bin/env python

import spidev
import time
import math
import numpy as np
from collections import deque

#some useful defines here:
start_frame = [0x00,0x00,0x00,0x00]
color_off = [0xFF,0x00,0x00,0x00]

class ZionStatusLEDs():
    def __init__(self, numLEDs=45, spi_speed=1000000):
        self.N = numLEDs
        self.spi = spidev.SpiDev()
        self.spi.open(0,0)
        #clear buffer just in case:
        self.spi.close()
        #re-open:
        self.spi.open(0,0)
        #set-up spi:
        self.spi.no_cs = True
        self.spi.lsbfirst = False
        self.spi.mode = 0b11
        self.spi.max_speed_hz = spi_speed
        
        # make sure all leds are off:
        self.stop_frame = math.floor((self.N+15)/16)*[0xFF,]
        self.turn_off_all()
        
        self.running = False
        
        
    def turn_off_all(self):
        self.send_init()
        for n in range(self.N+5):
            self.spi.writebytes(color_off)
#             time.sleep(0.1)
#         self.spi.writebytes(self.stop_frame)
            
    def send_init(self):
        self.spi.writebytes(start_frame)
        
    def set_color(self, brightness, R, G, B):
        #brightness is 5 bit number!
        if brightness<0 or brightness>=32:
            raise ValueError('Brightness must be a 5 bit integer!')
        elif R<0 or R>=256:
            raise ValueError('Brightness must be a 8 bit integer!')
        elif B<0 or B>=256:
            raise ValueError('Brightness must be a 8 bit integer!')
        elif G<0 or G>=256:
            raise ValueError('Brightness must be a 8 bit integer!')
        else:
            byte0 = 0xE0 | int(hex(brightness), 16)
            frame = [byte0, int(hex(B), 16), int(hex(G), 16), int(hex(R), 16)]
            self.send_init()
            for n in range(self.N):
                self.spi.writebytes(frame)
#             self.spi.writebytes(color_off)
            self.spi.writebytes(self.stop_frame)
            
    def pulse_color(self, brightness, R, G, B, rate=0.75):
        #first define ramp: (make sine wave??)
        brightnesses = list(range(1,brightness+1,1))+list(range(brightness-1,1,-1))
        while True: #todo how to interrupt/stop this?
            for b in brightnesses:
                self.set_color(b, R, G, B)
                time.sleep(1./(rate*len(brightnesses)))
    
    def spin_color(self, brightness, R,G,B, rate=1.2, window_length=9):
#         ramp_down = list(range(31,1,math.floor(-31/(math.ceil(window_length/2)))))[1:]
        ramp_down = np.linspace(start=brightness, stop=0, num=2+math.floor(window_length/2)).round().astype(int).tolist()[1:-1]
        ramp_up = np.linspace(start=0, stop=brightness, num=2+math.floor(window_length/2)).round().astype(int).tolist()[1:-1]
        #         brightnesses = deque(ramp_up+[31]+ramp_down+(self.N-window_length)*[0])
        brightnesses = deque(ramp_up+[31]+ramp_down+(self.N-len(ramp_up)-len(ramp_down)-1)*[0])

        while True:
            self.send_init()
            for n in range(self.N):
                byte0 = 0xE0 | int(hex(brightnesses[n]), 16)
                frame = [byte0, int(hex(B), 16), int(hex(G), 16), int(hex(R), 16)]
                self.spi.writebytes(frame)
            self.spi.writebytes(self.stop_frame)
            time.sleep(1./(rate*self.N))
            brightnesses.rotate(1)
         
leds = ZionStatusLEDs()
# leds.pulse_color(31, 0,125,255)
# leds.spin_color(31, 255,0,255, window_length=9)