// -----------------------------------------------------------------
// Description: A strip of Leds connected to a transistor controlled
// by an Attiny13. The μC sleeps most of the time, but is interrupted
// by a PIR on PCINT1, or a Hall Effect sensor on PCINT2. It will then
// light the leds, hold for a bit and and then fade out.
//
// Author: OneCircuit Date: Thursday 16 July 11:48:26 AEST 2020
// www.onecircuit.blogspot.com
// www.youtube.com/channel/UCTm3eCrN6wk-Ozt9ymyKIIg
// -----------------------------------------------------------------
//
// ATMEL ATTINY13 μC
//
// +-\/-+
// RESET--ACD0--5/A0--PCINT5--PB5 1| |8 VCC
// CLKI--ACD3--3/A3--PCINT3--PB3 2| |7 PB2--PCINT2--2/A1--SCK--ADC1
// ACD2--4/A2--PCINT4--PB4 3| |6 PB1--PCINT1---1---MISO--OCOB--INT0*
// GND 4| |5 PB0--PCINT0---0---MOSI--OCOA*
// +----+
// * indicates PWM port
//
#include <avr/pgmspace.h> // for reading the progmem values
#include <avr/interrupt.h> // for interrupt routines
#include <avr/sleep.h> // the sleep routines
#define StripLED PB0 // pwm pin
#define HEPin PCINT2 // Magnetic interrupt pin
#define PIRPin PCINT1 // PIR interrupt pin
volatile boolean triggered = false; // boolean for keeping track of interrupts
// The led strip will fade exponentially to compensate for human perception,
// which is not linear. You can calculate as a curve, but float values will blow
// the little Attiny13 out of the water, so a lookup table in progmem makes more
// sense for saving memory.
const uint8_t PROGMEM gamma8[] = {
0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4,
5, 5, 6, 6, 7, 8, 8, 9, 9, 10, 11, 11, 12, 13, 14, 14, 15,
16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29,
30, 31, 32, 34, 35, 36, 37, 39, 40, 41, 43, 44, 46, 47,
48, 50, 51, 53, 54, 56, 58, 59, 61, 63, 64, 66, 68, 69,
71, 73, 75, 77, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96,
98, 100, 102, 105, 107, 109, 111, 113, 116, 118, 120,
123, 125, 127, 130, 132, 134, 137, 139, 142, 144, 147,
150, 152, 155, 157, 160, 163, 165, 168, 171, 174, 176,
179, 182, 185, 188, 191, 194, 197, 200, 203, 206, 209,
212, 215, 218, 221, 224, 227, 230, 234, 237, 240, 243, 247, 250
};
void slowfade(boolean fadein) {
if (fadein) {
for (uint8_t lighting = 0; lighting < 150; lighting++) { // 150 steps
analogWrite(StripLED, pgm_read_byte(&gamma8[lighting])); // read from the lookup table
delay(6); // increase for a slower fade
}
}
else {
for (uint8_t lighting = 150; lighting > 0; lighting--) { // count backwards
analogWrite(StripLED, pgm_read_byte(&gamma8[lighting])); // from the lookup table
delay(80); // increase for a slower fade
}
}
}
void powerDown(void)
{
GIMSK |= (1 << PCIE); // activate Pin change interrupts
PCMSK |= ((1 << HEPin)|(1 << PIRPin)); // sets the Pin change interrupt mask
ADCSRA &= ~(1 << ADEN); // turn off ADC
ACSR |= (1 << ACD); // turn off Analog comparator.
sei(); // enable global interrupts
set_sleep_mode(SLEEP_MODE_PWR_DOWN); // sleep deeply little one
sleep_enable(); // enable sleep mode
sleep_mode(); // system sleeps here
sleep_disable(); // ISR routine returns here so wake up
GIMSK &= ~(1 << PCIE); // deactivate Pin change interrupts
ADCSRA |= (1 << ADEN); // turn on ADC
ACSR = (0 << ACD); // turn on Analog comparator.
delay(100); // settle time after waking up
}
ISR(PCINT0_vect)
{
triggered = true;
}
void setup ()
{
pinMode(HEPin, INPUT_PULLUP); // configure interrupt pin as input
pinMode(PIRPin, INPUT_PULLUP); // configure interrupt pin as input
pinMode(StripLED, INPUT); // LED pin input to start
} // end of setup
void loop () {
if (!triggered) {
powerDown(); // call the function that sleeps
}
else {
pinMode(StripLED, OUTPUT); // LED pin is now output
slowfade(true); // fade in
delay(60000); // hold that thought for 1 minute
slowfade(false); // fade out
pinMode (StripLED, INPUT); // configure transistor pin as input, saves power
delay(1000); // one second before re-trigger
triggered = false; // reset boolean
}
} // end of code
