Implement led control in another module

barista/Makefile

@@ -39,6 +39,9 @@ test_ntc: test/test_ntc.o ntc.o
 test_overheat: test/test_overheat.o overheat.o
 	gcc $^ -o $@ $(LIBS)
 
+test_led: test/test_led.o test/compat.o led.o
+	gcc $^ -o $@ $(LIBS)
+
 clean:
 	rm -f test/test_ntc.o ntc.o
 

barista/barista.ino

@@ -3,6 +3,7 @@
 
 #include "ntc.h"
 #include "overheat.h"
+#include "led.h"
 #include "pinout.h"
 #include <avr/wdt.h>
 
@@ -90,6 +91,9 @@ struct state {
 
 	struct overheat overheat;
 	unsigned long overheat_t0;
+
+	struct led red_led;
+	struct led green_led;
 } g_st;
 
 int read_input(int pin)
@@ -235,7 +239,7 @@ void proc_machine(struct state *st)
 			Serial.println("heating");
 		}
 	} else if (st->mstate == HEATING) {
-		if (temp > TEMP_MAX) {
+		if (temp > TEMP_MIN) {
 			st->mstate = HOT;
 			st->hot_t0 = millis();
 			st->buzz_state = BUZZ_HEY;
@@ -313,35 +317,33 @@ void do_proc(struct state *st, const struct input *input)
 void
 output_leds(const struct state *st)
 {
-	static int r = 0;
+	unsigned long t = millis();
-	static int g = 0;
 
-	if (st->mstate == HEATING || st->mstate == COOLING) {
+	if (st->mstate == SLEEPING) {
-		analogWrite(PIN_LED_RED, r);
+		led_off(&st->red_led);
-		setled(PIN_LED_GREEN, 0);
+		led_off(&st->green_led);
-		if (r >= 255)
+	} else if (st->mstate == HEATING) {
-			r = 0;
+		led_off(&st->red_led);
-		else
+		led_pattern(&st->green_led, t, 1000UL, "000123456789abcdefff");
-			r += 5;
+	} else if (st->mstate == COOLING) {
+		led_off(&st->red_led);
+		led_pattern(&st->green_led, t, 1000UL, "fffedcba987654321000");
 	} else if (st->mstate == HOT) {
-		setled(PIN_LED_RED, 0);
+		led_off(&st->red_led);
-		setled(PIN_LED_GREEN, 1);
+		led_on(&st->green_led);
-		r = 0;
 	} else if (st->mstate == PANIC_OVERHEAT) {
-		setled(PIN_LED_RED, 1);
+		led_pattern(&st->red_led,   t, 3000UL, "f0f0f0000000");
-		setled(PIN_LED_GREEN, 0);
+		led_pattern(&st->green_led, t, 3000UL, "000000f0f0f0");
 	} else if (st->mstate == BREWING_HOT || st->mstate == BREWING_COLD) {
-		setled(PIN_LED_RED, 0);
+		led_off(&st->red_led);
-		analogWrite(PIN_LED_GREEN, g);
+		led_pattern(&st->green_led, millis(), 2000UL, "0123456789abcdefedcba9876543210");
-		if (g >= 255)
-			g = 0;
-		else
-			g += 5;
 	} else {
-		setled(PIN_LED_RED, 0);
+		led_off(&st->red_led);
-		setled(PIN_LED_GREEN, 0);
+		led_off(&st->green_led);
-		r = 0;
 	}
+
+	analogWrite(PIN_LED_RED, led_level(&st->red_led, t));
+	analogWrite(PIN_LED_GREEN, led_level(&st->green_led, t));
 }
 
 void

barista/led.c

@@ -0,0 +1,71 @@
+/* Copyright (c) 2025 Rodrigo Arias Mallo <rodarima@gmail.com>
+ * SPDX-License-Identifier: GPL-3.0-or-later */
+
+#include "led.h"
+#include <string.h>
+
+void led_on(struct led *led)
+{
+	led->mode = LED_ON;
+}
+
+void led_off(struct led *led)
+{
+	led->mode = LED_OFF;
+}
+
+void led_pattern(struct led *led, unsigned long t_ms, unsigned long period_ms, const char *pattern)
+{
+	int n = strlen(pattern);
+	unsigned long step_ms = period_ms / n;
+
+	/* Don't change the current state */
+	if (led->mode == LED_PATTERN &&
+			led->step_ms == step_ms &&
+			led->pattern == pattern)
+		return;
+
+	led->mode = LED_PATTERN;
+	led->pat_i = 0;
+	led->pat_n = n;
+	led->pattern = pattern;
+	led->step_ms = step_ms;
+	led->t_ms = t_ms;
+}
+
+/* Return led level brightness in [0, 255] at current time */
+int led_level(struct led *led, unsigned long t_ms)
+{
+	if (led->mode == LED_OFF)
+		return 0;
+
+	if (led->mode == LED_ON)
+		return 255;
+
+	if (led->mode == LED_PATTERN) {
+		while (led->t_ms + led->step_ms < t_ms) {
+			led->t_ms += led->step_ms;
+			led->pat_i++;
+			if (led->pat_i >= led->pat_n)
+				led->pat_i = 0;
+		}
+
+		int c = led->pattern[led->pat_i];
+		int level;
+
+		if (c >= '0' && c <= '9')
+			level = 17 * (c - '0');
+		else
+			level = 17 * (10 + (c - 'a'));
+
+		if (level < 0)
+			level = 0;
+		else if (level > 255)
+			level = 255;
+
+		return level;
+	}
+
+	/* Unknown mode, turn off */
+	return 0;
+}

barista/led.h

@@ -0,0 +1,35 @@
+/* Copyright (c) 2025 Rodrigo Arias Mallo <rodarima@gmail.com>
+ * SPDX-License-Identifier: GPL-3.0-or-later */
+
+#ifndef BARISTA_LED_H
+#define BARISTA_LED_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+enum led_mode {
+	LED_OFF = 0,
+	LED_ON,
+	LED_PATTERN,
+};
+
+struct led {
+	enum led_mode mode;
+	const char *pattern;
+	int pat_i;
+	int pat_n;
+	unsigned long step_ms;
+	unsigned long t_ms;
+};
+
+void led_on(struct led *led);
+void led_off(struct led *led);
+void led_pattern(struct led *led, unsigned long t_ms, unsigned long period_ms, const char *pattern);
+int led_level(struct led *led, unsigned long t_ms);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* BARISTA_LED_H */

barista/test/compat.c

@@ -0,0 +1,13 @@
+/* Copyright (c) 2025 Rodrigo Arias Mallo <rodarima@gmail.com>
+ * SPDX-License-Identifier: GPL-3.0-or-later */
+
+#include "compat.h"
+#include <time.h>
+
+unsigned long millis(void)
+{
+	struct timespec ts;
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+
+	return ts.tv_sec * 1000UL + ts.tv_nsec / 1000000UL;
+}

barista/test/compat.h

@@ -0,0 +1,17 @@
+/* Copyright (c) 2025 Rodrigo Arias Mallo <rodarima@gmail.com>
+ * SPDX-License-Identifier: GPL-3.0-or-later */
+
+#ifndef BARISTA_COMPAT_H
+#define BARISTA_COMPAT_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+unsigned long millis(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* BARISTA_COMPAT_H */

barista/test/test_led.c

@@ -0,0 +1,42 @@
+/* Copyright (c) 2025 Rodrigo Arias Mallo <rodarima@gmail.com>
+ * SPDX-License-Identifier: GPL-3.0-or-later */
+
+#include <stdio.h>
+#include "led.h"
+#include "compat.h"
+
+int main(void)
+{
+	struct led led;
+	unsigned long t0 = millis();
+	unsigned long step = 1000UL;
+
+	led_pattern(&led, t0, step, "000123456789abcdefff");
+
+	int last_level = -1;
+
+	unsigned long last_t = millis();
+	while (1) {
+		unsigned long t = millis();
+
+		if (t - t0 >= 10000UL)
+			break;
+
+		if (t - last_t < 50UL)
+			continue;
+
+		int level = led_level(&led, millis());
+		printf("|");
+		for (int i = 0; i < 256; i+=4) {
+			if (i < level)
+				printf("=");
+			else
+				printf(" ");
+		}
+		printf("|\n");
+		last_level = level;
+		last_t = t;
+	}
+
+	return 0;
+}