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#!/usr/bin/env python
# NiteLite - a python daemon process started at system boot, and stopped on shutdown
# - the default LED pattern is twinkling but if motion is detected, one of 4
# different patterns are chosen and these are used for 10s after motion detection
#
# Please see our GitHub repository for more information: https://github.com/pistuffing/nitelite/piglow
#
# Once running you'll need to press ctrl-C to cancel stop the script or run
# sudo /etc/init.d/nitelited.sh stop
from __future__ import division
import signal
import time
from smbus import SMBus
import RPi.GPIO as GPIO
import random
import math
# command register addresses for the SN3218 IC used in PiGlow
CMD_ENABLE_OUTPUT = 0x00
CMD_ENABLE_LEDS = 0x13
CMD_SET_PWM_VALUES = 0x01
CMD_UPDATE = 0x16
class PiGlow:
i2c_addr = 0x54 # fixed i2c address of SN3218 ic
bus = None
def __init__(self, i2c_bus=1):
self.bus = SMBus(i2c_bus)
# first we tell the SN3218 to enable output (turn on)
self.write_i2c(CMD_ENABLE_OUTPUT, 0x01)
# then we ask it to enable each bank of LEDs (0-5, 6-11, and 12-17)
self.write_i2c(CMD_ENABLE_LEDS, [0xFF, 0xFF, 0xFF])
def update_leds(self, values):
self.write_i2c(CMD_SET_PWM_VALUES, values)
self.write_i2c(CMD_UPDATE, 0xFF)
def write_i2c(self, reg_addr, value):
# if a single value is provided then wrap it in a list so we can treat
if not isinstance(value, list):
value = [value];
# write the data to the SN3218
self.bus.write_i2c_block_data(self.i2c_addr, reg_addr, value)
LED_ARM_TOP = 0
LED_ARM_LEFT = 1
LED_ARM_RIGHT = 2
LED_COLOUR_RED = 0
LED_COLOUR_ORANGE = 1
LED_COLOUR_YELLOW = 2
LED_COLOUR_GREEN = 3
LED_COLOUR_BLUE = 4
LED_COLOUR_WHITE = 5
LED_PATTERN_TWINKLE = 0
LED_PATTERN_GLOW = 1
LED_PATTERN_SWELL = 2
LED_PATTERN_DROPLET = 3
LED_PATTERN_SNAKE = 4
#------------------------------------------------------------
# Set up the LED spiral arm / colour mappings
#------------------------------------------------------------
led_map = []
for arm in range(0,3):
led_map.append([])
for colour in range(0,6):
led_map[arm].append(0)
led_map[LED_ARM_TOP][LED_COLOUR_RED] = 6
led_map[LED_ARM_TOP][LED_COLOUR_ORANGE] = 7
led_map[LED_ARM_TOP][LED_COLOUR_YELLOW] = 8
led_map[LED_ARM_TOP][LED_COLOUR_GREEN] = 5
led_map[LED_ARM_TOP][LED_COLOUR_BLUE] = 4
led_map[LED_ARM_TOP][LED_COLOUR_WHITE] = 9
led_map[LED_ARM_LEFT][LED_COLOUR_RED] = 0
led_map[LED_ARM_LEFT][LED_COLOUR_ORANGE] = 1
led_map[LED_ARM_LEFT][LED_COLOUR_YELLOW] = 2
led_map[LED_ARM_LEFT][LED_COLOUR_GREEN] = 3
led_map[LED_ARM_LEFT][LED_COLOUR_BLUE] = 14
led_map[LED_ARM_LEFT][LED_COLOUR_WHITE] = 12
led_map[LED_ARM_RIGHT][LED_COLOUR_RED] = 17
led_map[LED_ARM_RIGHT][LED_COLOUR_ORANGE] = 16
led_map[LED_ARM_RIGHT][LED_COLOUR_YELLOW] = 15
led_map[LED_ARM_RIGHT][LED_COLOUR_GREEN] = 13
led_map[LED_ARM_RIGHT][LED_COLOUR_BLUE] = 11
led_map[LED_ARM_RIGHT][LED_COLOUR_WHITE] = 10
#------------------------------------------------------------
# Set up the LED number array
#------------------------------------------------------------
leds = []
for led in range(0, 18):
leds.append(0)
#------------------------------------------------------------
# Set up the LED brightness array
#------------------------------------------------------------
levels = [0, 1, 2, 4, 8, 16, 32, 64, 128]
#------------------------------------------------------------
# Set up the shutdown handler
#------------------------------------------------------------
def ShutdownHandler(signal, frame):
global keep_looping
keep_looping = False
#------------------------------------------------------------
# Set up the PIR movement detection callback
#------------------------------------------------------------
def PIRCallback(channel):
global motion_detected_time
global led_pattern
global leds
if led_pattern == LED_PATTERN_TWINKLE:
led_pattern = random.randint(1, 4)
motion_detected_time = time.time()
#------------------------------------------------------------
# Set up the PIR movement detection
#------------------------------------------------------------
GPIO_PIR = 18
GPIO.setmode(GPIO.BOARD)
GPIO.setup(GPIO_PIR, GPIO.IN, GPIO.PUD_DOWN)
GPIO.add_event_detect(GPIO_PIR, GPIO.RISING, PIRCallback, 0)
#------------------------------------------------------------
# Final steps of setup
#------------------------------------------------------------
signal.signal(signal.SIGINT, ShutdownHandler)
piglow = PiGlow(1)
keep_looping = True
motion_detected_time = time.time() - 5.1
while keep_looping:
#------------------------------------------------------------
# Drop back to the default LED pattern?
#------------------------------------------------------------
if time.time() - motion_detected_time >= 5.0:
led_pattern = LED_PATTERN_TWINKLE
twinkle_count = 0
#------------------------------------------------------------
# TWINKLE: 0: Random LED lit with random, decaying brightness
#------------------------------------------------------------
if led_pattern == LED_PATTERN_TWINKLE:
# dim all lit LEDs by one step in the levels list
# first find the index into the brightness list
# This relies on the fact that values in the levels
# list are all 2^n
for led in range(0, 18):
mant, level = math.frexp(leds[led])
if mant == 0.0:
level = 0
if level > 0:
leds[led] = levels[level - 1]
# Add a random LED every 5 cycles with random brightness
if twinkle_count == 0:
leds[random.randint(0, 17)] = levels[random.randint(0, 8)]
twinkle_count = (twinkle_count + 1) % 10
piglow.update_leds(leds)
time.sleep(0.1)
#------------------------------------------------------------
# GLOW: 1; All LEDs glow at a low level
#------------------------------------------------------------
elif led_pattern == LED_PATTERN_GLOW:
for led in range(0, 18):
leds[led] = levels[4]
piglow.update_leds(leds)
#------------------------------------------------------------
# SWELL: 2; All LEDs brightness swelling up and down
#------------------------------------------------------------
elif led_pattern == LED_PATTERN_SWELL:
for level in range(0, 8):
for led in range(0, 18):
leds[led] = levels[level]
piglow.update_leds(leds)
time.sleep(0.1)
for level in range(8, 0, -1):
for led in range(0, 18):
leds[led] = levels[level]
piglow.update_leds(leds)
time.sleep(0.1)
#------------------------------------------------------------
# DROPLET 3; Same colour sweeping up and down all the arms together at fixed brightness
#------------------------------------------------------------
elif led_pattern == LED_PATTERN_DROPLET:
for colour in range(0, 5):
for arm in range(0, 3):
leds[led_map[arm][colour]] = 0x80
piglow.update_leds(leds)
for arm in range(0,3):
leds[led_map[arm][colour]] = 0x00
time.sleep(0.1)
for colour in range(5, 0, -1):
for arm in range(0,3):
leds[led_map[arm][colour]] = 0x80
piglow.update_leds(leds)
for arm in range(0,3):
leds[led_map[arm][colour]] = 0x00
time.sleep(0.1)
#------------------------------------------------------------
# SNAKE: 4; Trace up and down each arm ini turn getting brighter towards the centre
#------------------------------------------------------------
elif led_pattern == LED_PATTERN_SNAKE:
for arm in range(0, 3):
for colour in range (0, 5):
leds[led_map[arm][colour]] = levels[colour + 1]
piglow.update_leds(leds)
time.sleep(0.1)
for colour in range (5, 0, -1):
leds[led_map[arm][colour]] = levels[colour + 1]
piglow.update_leds(leds)
time.sleep(0.1)
for colour in range(0, 6):
leds[led_map[arm][colour]] = 0x00
# set all the LEDs to "off" when Ctrl+C is pressed before exiting
for led in range(0, 18):
leds[led] = 0x0
piglow.update_leds(leds)
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