282 lines
6.7 KiB
C
282 lines
6.7 KiB
C
/**
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* @file main.c
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* @brief Bike rear light implementation for ATTINY202.
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*
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*/
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#include <stdint.h>
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#include <stdbool.h>
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#include <avr/io.h>
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#include <util/delay.h>
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/** @defgroup LED_Masks LED bitmasks for PORTA
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* @{
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*/
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#define PA1_SET_MASK 0x02 ///< LED 1–2
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#define PA2_SET_MASK 0x04 ///< LED 3–6
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#define PA3_SET_MASK 0x08 ///< LED 7–8
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#define PA6_SET_MASK 0x40 ///< Switch input (was green LED pin) TODO: Switch to PA0
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#define PA7_SET_MASK 0x80 ///< Red LED
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/** @} */
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#define MAIN_LOOP_SLEEP 10U // Main loop delay in ms (system tick)
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#define BUTTON_PRESS_DURATION 1000U // Button needs to be pressed for at least 1000ms
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/** @brief Convert milliseconds to system ticks (integer division). */
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#define MS_TO_TICKS(ms) ((ms) / MAIN_LOOP_SLEEP)
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/** @brief Global flags */
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volatile bool bLedEnabled = true;
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volatile bool bBtnPressed = false;
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// Function forward declarations
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void blinkLed(void);
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static inline void leds_off(void);
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static inline void leds_on(void);
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static void handleSwitch(void);
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/**
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* @brief Main entry point.
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*
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* Initializes I/O ports and runs the main loop, periodically calling @ref blinkLed().
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*
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* @return never returns
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*/
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int main(void)
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{
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// --- configure LED pins as outputs ---
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VPORTA.DIR = (PA1_SET_MASK | PA2_SET_MASK | PA3_SET_MASK |
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/*PA6_SET_MASK |*/ // PA6 now input (switch)
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PA7_SET_MASK);
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// Configure PA6 as input with pull-up TODO: Switch to PA0
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VPORTA.DIR &= ~PA6_SET_MASK; // Input
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PORTA.PIN6CTRL = PORT_PULLUPEN_bm; // Pull-up enabled
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// --- ensure all LEDs off at startup ---
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leds_off();
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VPORTA.OUT &= (uint8_t) ~(PA7_SET_MASK);
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bool bLedEnabledOld = bLedEnabled;
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while (true)
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{
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handleSwitch(); // check switch state
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if (bBtnPressed)
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{
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leds_on();
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}
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else
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{
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leds_off();
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}
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if (bLedEnabledOld != bLedEnabled)
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{
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bLedEnabledOld = bLedEnabled;
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leds_off();
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_delay_ms(1000);
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}
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else
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{
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if ((bLedEnabled) && (!bBtnPressed))
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{
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blinkLed();
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}
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}
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_delay_ms(MAIN_LOOP_SLEEP);
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}
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}
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/**
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* @brief Switch off all controlled LEDs (PA1, PA2, PA3).
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*
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* @note Declared inline for speed (single instruction sequence).
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*/
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static inline void leds_off(void)
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{
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VPORTA.OUT &= (uint8_t) ~(PA1_SET_MASK | PA2_SET_MASK | PA3_SET_MASK);
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}
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/**
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* @brief Switch on all controlled LEDs (PA1, PA2, PA3).
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*
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* @note Declared inline for speed (single instruction sequence).
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*/
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static inline void leds_on(void)
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{
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VPORTA.OUT |= (PA1_SET_MASK | PA2_SET_MASK | PA3_SET_MASK);
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}
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/**
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* @brief Handle momentary switch input on PA6. TODO: Switch to PA0
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*
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* A press longer than 2 seconds toggles ::bLedEnabled.
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* Uses simple state and counters for debouncing and long-press detection.
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*/
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static void handleSwitch(void)
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{
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static uint16_t pressTicks = 0; ///< press duration counter
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static bool prevPressed = false; ///< previous switch state
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bool pressed = !(VPORTA.IN & PA6_SET_MASK); // active-low
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if (pressed)
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{
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bBtnPressed = true;
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if (pressTicks < 0xFFFF)
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{
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// prevent overflow
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pressTicks++;
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}
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}
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else
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{
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bBtnPressed = false;
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pressTicks = 0;
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}
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if (prevPressed && pressTicks >= MS_TO_TICKS(BUTTON_PRESS_DURATION))
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{
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// long press detected → toggle blinking
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bLedEnabled = !bLedEnabled;
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}
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prevPressed = pressed;
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}
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/**
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* @brief LED blink state machine (bike rear light style).
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*
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* Implements a "rounded" pulsing blink sequence:
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*
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* Normal cycle (~1 s total):
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* - Step 0: all off, wait 100 ms
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* - Step 1: LED 1–2 + 7–8 ON, wait 100 ms
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* - Step 2: all LEDs ON, wait 200 ms
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* - Step 3: only LED 1–2 ON, wait 100 ms
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* - Step 4: all off, wait 400 ms → restart
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*
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* Special behavior:
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* - Every 3rd cycle, after step 4, all LEDs are switched on for 300 ms.
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*
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* Timing is based on @ref MAIN_LOOP_SLEEP ticks.
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*/
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void blinkLed(void)
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{
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// --- precomputed constants (compile-time) ---
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const uint8_t T50 = MS_TO_TICKS(50); ///< 50 ms in ticks
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const uint8_t T100 = MS_TO_TICKS(100); ///< 100 ms in ticks
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const uint8_t T250 = MS_TO_TICKS(250); ///< 250 ms in ticks
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// --- persistent state ---
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static uint16_t counter = 0; ///< counts ticks for current state
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static uint8_t state = 0; ///< current step in the sequence
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static uint8_t cycle = 0; ///< cycle counter (0–2)
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counter++;
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switch (state)
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{
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case 0: // all LEDs off, wait 250 ms
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leds_off();
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if (counter >= T250)
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{
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counter = 0;
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state = 2;
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}
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break;
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case 2: // LED 1–2 + 7–8 on, wait 50 ms
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VPORTA.OUT |= (PA1_SET_MASK | PA3_SET_MASK);
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if (counter >= T50)
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{
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counter = 0;
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state = 5;
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}
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break;
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case 5: // all LEDs off, wait 100 ms
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leds_off();
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if (counter >= T100)
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{
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counter = 0;
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state = 7;
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}
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break;
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case 7: // LED 1–2 + 7–8 on, wait 50 ms
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VPORTA.OUT |= (PA1_SET_MASK | PA3_SET_MASK);
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if (counter >= T50)
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{
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counter = 0;
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state = 10;
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}
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break;
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case 10: // all LEDs off, wait 250 ms
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leds_off();
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if (counter >= T250)
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{
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counter = 0;
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state = 12;
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}
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break;
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case 12: // LED 3–6 on, wait 50 ms
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VPORTA.OUT |= PA2_SET_MASK;
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if (counter >= T50)
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{
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counter = 0;
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state = 14;
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}
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break;
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case 14: // all LEDs off, wait 100 ms
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leds_off();
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if (counter >= T100)
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{
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counter = 0;
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state = 16;
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}
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break;
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case 16: // LED 3–6 on, wait 50 ms
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VPORTA.OUT |= PA2_SET_MASK;
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if (counter >= T50)
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{
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counter = 0;
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state = 18;
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}
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break;
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case 18: // all LEDs off, wait 250 ms
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leds_off();
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if (counter >= T250)
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{
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counter = 0;
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if (++cycle >= 3)
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{
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cycle = 0;
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state = 20; // special all-LEDs-on state
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}
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else
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{
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state = 0; // restart normal cycle
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}
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}
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break;
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case 20: // special: all LEDs on for 250 ms
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VPORTA.OUT |= (PA1_SET_MASK | PA2_SET_MASK | PA3_SET_MASK);
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if (counter >= T250)
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{
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counter = 0;
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state = 0; // restart normal sequence
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}
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break;
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}
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}
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