WIP: started implementing the countdown state machine

src/main.c

@@ -1,16 +1,24 @@
 #include "hardware/gpio.h"
 #include "hardware/irq.h"
-#include "hardware/pwm.h"
-#include "hardware/irq.h"
 
 #include "sseg.h"
+#include "buttons.h"
+#include "buzzer.h"
 #include "pinout.h"
 
 #include <pico/stdlib.h>
 
-const uint8_t all_gpios[] = {
+typedef enum {
-	OUTPUT_ENABLE_PIN,
+	COUNTDOWN_UNINITIALIZED,
-};
+	COUNTDOWN_STOPPED,
+	COUNTDOWN_STARTING,
+	COUNTDOWN_RUNNING
+} countdown_state_t;
+
+static countdown_state_t m_countdown_state;
+static uint32_t          m_last_state_change_time;
+
+static uint32_t          m_countdown_off_time;
 
 static volatile bool m_ms_triggered;
 static uint32_t      m_next_ms_trigger;
@@ -45,62 +53,139 @@ static void configure_ms_trig_alarm(void)
 	m_next_ms_trigger = timer_hw->timelr + 10000;
 }
 
+static void update_countdown_fsm(uint32_t time_ms)
+{
+	countdown_state_t last_state = m_countdown_state;
+
+	// note: this calculation works even if time_ms overflows
+	uint32_t time_in_state = time_ms - m_last_state_change_time;
+	bool state_entered = (time_in_state == 1);
+
+	uint32_t countdown_time_remaining; // only used in COUNTDOWN_RUNNING state
+
+	switch(m_countdown_state) {
+		case COUNTDOWN_UNINITIALIZED:
+			m_countdown_state = COUNTDOWN_STOPPED;
+			break;
+
+		case COUNTDOWN_STOPPED:
+			if(state_entered) {
+				sseg_set_char(0, 'o', false);
+				sseg_set_char(1, 'f', false);
+				sseg_set_char(2, 'f', false);
+			}
+
+			if(buttons_get_events(BTN_ON) & BTN_EVENT_PRESSED) {
+				m_countdown_state = COUNTDOWN_STARTING;
+			}
+			break;
+
+		case COUNTDOWN_STARTING:
+			// TODO: show a fancy animation + beep code
+
+			if(buttons_get_events(BTN_ON) & BTN_EVENT_RELEASED) {
+				// button released too early -> back to stopped state
+				m_countdown_state = COUNTDOWN_STOPPED;
+			}
+
+			if(time_in_state == 3000) {
+				m_countdown_off_time = time_ms + 30 * 60 * 1000;
+				m_countdown_state = COUNTDOWN_RUNNING;
+			}
+			break;
+
+		case COUNTDOWN_RUNNING:
+			if(state_entered) {
+				// countdown has been started -> switch on the load
+				gpio_put(OUTPUT_ENABLE_PIN, true);
+			}
+
+			countdown_time_remaining = m_countdown_off_time - time_ms;
+
+			// TODO: show time on display
+			// TODO: off button handling
+			// TODO: on button handling (extend time)
+
+			// beep codes
+			switch(countdown_time_remaining) {
+				case 300000: // short beep at 5 minutes remaining
+				case 60000: // double beep at 1 minute remaining
+				case 59600:
+				case 10000: // triple beep at 10 seconds remaining
+				case 9600:
+				case 9200:
+				case 5000: // count down the last 5 seconds
+				case 4000:
+				case 3000:
+				case 2000:
+				case 1000: // last second beep is longer
+					buzzer_on(1000);
+					break;
+
+				case 299800:
+				case 59800:
+				case 59400:
+				case 9800:
+				case 9400:
+				case 9000:
+				case 4800:
+				case 3800:
+				case 2800:
+				case 1800:
+				case 500:
+					buzzer_off();
+					break;
+			}
+
+			if(countdown_time_remaining == 0) {
+				// switch off the load
+				gpio_put(OUTPUT_ENABLE_PIN, false);
+				m_countdown_state = COUNTDOWN_STOPPED;
+			}
+	}
+
+	if(m_countdown_state != last_state) {
+		m_last_state_change_time = time_ms;
+	}
+}
+
 int main()
 {
 	//stdio_init_all();
 	//printf("Hello, world!\n");
 
-	bool power_switch_state = false;
+	gpio_init(OUTPUT_ENABLE_PIN);
+	gpio_put(OUTPUT_ENABLE_PIN, false);
+	gpio_set_dir(OUTPUT_ENABLE_PIN, true);
 
-	for(size_t i = 0; i < sizeof(all_gpios); i++) {
+	buzzer_init();
-		gpio_init(all_gpios[i]);
+	buttons_init();
-		gpio_put(all_gpios[i], false);
-		gpio_set_dir(all_gpios[i], true);
-	}
 
-	gpio_put(OUTPUT_ENABLE_PIN, true);
+	buzzer_on(1000);
-
-	// set up PWM for 50 kHz @ 512 steps resolution
-	uint slice_num = pwm_gpio_to_slice_num(BUZZER_PIN);
-
-	pwm_set_clkdiv_int_frac(slice_num, 244, (14 << 4) / 100); // 125 MHz / 244.14 / 512 = 1 kHz
-	gpio_set_function(BUZZER_PIN, GPIO_FUNC_PWM);
-	pwm_set_wrap(slice_num, 512);
-	pwm_set_chan_level(slice_num, PWM_CHAN_B, 1 * 512 / 100);
-	pwm_set_enabled(slice_num, true);
 
 	sleep_ms(200);
 
-	pwm_set_enabled(slice_num, false);
+	buzzer_off();
-	pwm_set_clkdiv_int_frac(slice_num, 122, (7 << 4) / 100); // 125 MHz / 122.07 / 512 = 2 kHz
+	buzzer_on(2000);
-	pwm_set_enabled(slice_num, true);
-
 
 	sleep_ms(200);
 
-	pwm_set_enabled(slice_num, false);
+	buzzer_off();
-	pwm_set_clkdiv_int_frac(slice_num, 61, (3 << 4) / 100); // 125 MHz / 61.03 / 512 = 4 kHz
+	buzzer_on(4000);
-	pwm_set_enabled(slice_num, true);
 
 	sleep_ms(200);
 
-	pwm_set_enabled(slice_num, false);
+	buzzer_off();
-	gpio_init(BUZZER_PIN);
-	gpio_put(BUZZER_PIN, false);
-	gpio_set_dir(BUZZER_PIN, true);
 
 	sleep_ms(2400);
 
-	pwm_set_enabled(slice_num, false);
-	gpio_init(BUZZER_PIN);
-
-	gpio_put(OUTPUT_ENABLE_PIN, false);
-
 	sseg_init();
 
 	configure_ms_trig_alarm();
 	arm_ms_trig_alarm();
 
+	m_countdown_state = COUNTDOWN_UNINITIALIZED;
+
 	uint32_t ms_counter = 0;
 	while (true) {
 		sseg_loop();
@@ -109,6 +194,11 @@ int main()
 			m_ms_triggered = false;
 
 			ms_counter++;
+
+			buttons_update_state(ms_counter);
+
+			update_countdown_fsm(ms_counter);
+
 			sseg_set_char(2, '0' + (ms_counter / 100) % 10, false);
 			sseg_set_char(1, '0' + (ms_counter / 1000) % 10, true);
 			sseg_set_char(0, '0' + (ms_counter / 10000) % 10, false);