/*
* Traffic light
*
* Copyright (C) 2019-2022 Aurelien Jarno
*
* Authors:
* Aurelien Jarno <aurelien@aurel32.net>
*
* This work is licensed under the terms of the GNU GPL, version 2.
* See the COPYING file in the same directory as this file.
*/
/**********************************************************************
* Global defines *
**********************************************************************/
/* CPU */
#define F_CPU 8000000UL /* 8 MHz */
/* I/O pins */
#define BUTTON PB0 /* Also DATA prog */
#define LED_DATA PB1 /* Also CLK prog */
#define LED_PWR PB2
#define RESET PB3
/**********************************************************************
* Includes *
**********************************************************************/
#include <avr/interrupt.h>
#include <avr/io.h>
#include <avr/pgmspace.h>
#include <avr/sleep.h>
#include <avr/wdt.h>
#include <stdint.h>
#include <util/delay.h>
/**********************************************************************
* State machine *
**********************************************************************/
enum state {
state_off,
state_red,
state_orange,
state_green,
state_blinking_on,
state_blinking_off,
};
struct state_desc {
const struct __attribute__((__packed__)) {
uint8_t r;
uint8_t g;
uint8_t b;
} leds[3];
uint16_t duration;
enum state next;
enum state next_button_short;
enum state next_button_medium;
enum state next_button_long;
};
const struct state_desc states_desc[] = {
[state_off] = {
.leds = {
{ .r = 0x00, .g = 0x00, .b = 0x00, },
{ .r = 0x00, .g = 0x00, .b = 0x00, },
{ .r = 0x00, .g = 0x00, .b = 0x00, },
},
.duration = 1,
.next = state_off,
.next_button_short = state_off,
.next_button_medium = state_off,
.next_button_long = state_off,
},
[state_green] = {
.leds = {
{ .r = 0x00, .g = 0x00, .b = 0x00, },
{ .r = 0x00, .g = 0x00, .b = 0x00, },
{ .r = 0x00, .g = 0x7f, .b = 0x00, },
},
.duration = 13000,
.next = state_orange,
.next_button_short = state_orange,
.next_button_medium = state_blinking_on,
.next_button_long = state_off,
},
[state_orange] = {
.leds = {
{ .r = 0x00, .g = 0x00, .b = 0x00, },
{ .r = 0x7f, .g = 0x2f, .b = 0x00, },
{ .r = 0x00, .g = 0x00, .b = 0x00, },
},
.duration = 1500,
.next = state_red,
.next_button_short = state_red,
.next_button_medium = state_blinking_on,
.next_button_long = state_off,
},
[state_red] = {
.leds = {
{ .r = 0x7f, .g = 0x00, .b = 0x00, },
{ .r = 0x00, .g = 0x00, .b = 0x00, },
{ .r = 0x00, .g = 0x00, .b = 0x00, },
},
.duration = 15000,
.next = state_green,
.next_button_short = state_green,
.next_button_medium = state_blinking_on,
.next_button_long = state_off,
},
[state_blinking_on] = {
.leds = {
{ .r = 0x00, .g = 0x00, .b = 0x00, },
{ .r = 0x7f, .g = 0x2f, .b = 0x00, },
{ .r = 0x00, .g = 0x00, .b = 0x00, },
},
.duration = 500,
.next = state_blinking_off,
.next_button_short = state_blinking_off,
.next_button_medium = state_red,
.next_button_long = state_off,
},
[state_blinking_off] = {
.leds = {
{ .r = 0x00, .g = 0x00, .b = 0x00, },
{ .r = 0x00, .g = 0x00, .b = 0x00, },
{ .r = 0x00, .g = 0x00, .b = 0x00, },
},
.duration = 500,
.next = state_blinking_on,
.next_button_short = state_blinking_on,
.next_button_medium = state_red,
.next_button_long = state_off,
},
};
/**********************************************************************
* Interrupt handlers *
**********************************************************************/
/* Do nothing, this is only used to wake-up the MCU */
EMPTY_INTERRUPT(PCINT0_vect);
/**********************************************************************
* Functions *
**********************************************************************/
static void set_leds(const uint8_t *data, uint8_t len)
{
uint8_t outlo, outhi;
outlo = PORTB & ~(1 << LED_DATA);
outhi = PORTB | (1 << LED_DATA);
/* Reset signal */
PORTB = outlo;
_delay_us(280);
/* Send all bits */
for (uint8_t i = 0; i < len; i++) {
asm volatile(
" ldi __tmp_reg__, 8 \n\t"
"loop: \n\t"
" out %[port], %[outhi] \n\t"
" nop \n\t"
" sbrs %[data], 7 \n\t"
" out %[port], %[outlo] \n\t"
" lsl %[data] \n\t"
" nop \n\t"
" nop \n\t"
" out %[port], %[outlo] \n\t"
" dec __tmp_reg__ \n\t"
" brne loop \n\t"
:
: [data] "r" (data[i]),
[port] "I" (_SFR_IO_ADDR(PORTB)),
[outhi] "r" (outhi),
[outlo] "r" (outlo)
: "cc"
);
}
}
/**********************************************************************
* Main code *
**********************************************************************/
int main(void)
{
/* Initialization: disable interrupts, clear watchdog */
cli();
wdt_reset();
/* Switch to calibrated internal 8 MHz oscillator without prescaler,
corresponding to a 8 MHz CPU clock */
CCP = 0xD8;
CLKMSR = 0x00;
CCP = 0xD8;
CLKPSR = 0x00;
/* Disable unused peripherals: ANA_COMP, TIM0, VLM, WDT */
ACSR = (1 << ACD);
PRR = (1 << PRADC) | (1 << PRTIM0);
VLMCSR = 0x00;
CCP = 0xD8;
WDTCSR = 0x00;
/* Setup LED pins as low output, BUTTON and RESET pins as input with
* pull-up */
PORTCR = 0x00;
PORTB = 0x00;
PUEB = (1 << BUTTON) | (1 << RESET);
DDRB = (1 << LED_PWR) | (1 << LED_DATA);
/* Setup interrupt on button change */
PCMSK = (1 << PCINT0);
PCICR = (1 << PCIE0);
for (;;) {
/* Reset power-on duration and start with the red color */
uint32_t on_duration = 0;
uint16_t button_duration = 0;
enum state state = state_red;
/* Power-on the LED and wait for it to be ready */
PORTB |= (1 << LED_PWR);
_delay_ms(10);
/* Loop through all the states until reaching the off state */
while (state != state_off) {
set_leds((const uint8_t *)states_desc[state].leds,
sizeof(states_desc[state].leds));
for (uint16_t d = states_desc[state].duration; d > 0; d--) {
_delay_ms(1);
on_duration++;
/* Count the button push time, and debounce the button by
* ignoring short pulses. */
if ((PINB & (1 << BUTTON)) == 0) {
if (button_duration != 65535) {
button_duration++;
}
} else if (button_duration > 10) {
break;
} else {
button_duration = 0;
}
}
if (((PINB & (1 << BUTTON)) != 0) && button_duration > 10) {
if (button_duration < 500) {
state = states_desc[state].next_button_short;
} else if (button_duration < 1500) {
state = states_desc[state].next_button_medium;
} else {
state = states_desc[state].next_button_long;
}
on_duration = 0;
button_duration = 0;
} else if (on_duration > 1800000) {
state = state_off;
} else {
state = states_desc[state].next;
}
}
/* Power-off the LED */
PORTB &= ~(1 << LED_PWR);
/* Clear and allow interrupts to wake-up the MCU and go to power down mode */
PCIFR |= (1 << PCIF0);
set_sleep_mode(SLEEP_MODE_PWR_DOWN);
sei();
sleep_mode();
/* Returned from interrupt, disable interrupts */
cli();
/* Wait for the button to be released */
while ((PINB & (1 << BUTTON)) == 0) {
;;
}
}
/* Never reached */
return 0;
}