feat(personal-state): Convert personal state to use the work queue

This reduces the power consumption of the system by around .1 mA when
the personal state is not active.

Documentation/overview.rst

@@ -29,8 +29,6 @@ number of tasks that will have been keeping card10 running.  These are:
 +--------------------+-------------------------------+----------+-------------------------------------------+
 | `vInterruptsTask`_ | ``interrupts_task`` (static)  | +2       | Interrupt dispatcher worker               |
 +--------------------+-------------------------------+----------+-------------------------------------------+
-| `vLedTask`_        | -/-                           | +1       | LED Animations                            |
-+--------------------+-------------------------------+----------+-------------------------------------------+
 | `vMAX30001Task`_   | ``max30001_task_id`` (static) | +1       | `MAX30001`_ ECG driver                    |
 +--------------------+-------------------------------+----------+-------------------------------------------+
 | `vBhi160Task`_     | ``bhi160_task_id`` (static)   | +1       | `BHI160`_ sensor fusion driver            |

epicardium/main.c

@@ -172,17 +172,6 @@ int main(void)
 		}
 	}
 
-	/* LEDs */
-	if (xTaskCreate(
-		    vLedTask,
-		    (const char *)"LED",
-		    configMINIMAL_STACK_SIZE,
-		    NULL,
-		    tskIDLE_PRIORITY + 1,
-		    NULL) != pdPASS) {
-		panic("Failed to create %s task!", "LED");
-	}
-
 	/* Lifecycle */
 	if (xTaskCreate(
 		    vLifecycleTask,

epicardium/modules/personal_state.c

@@ -2,20 +2,36 @@
 #include "leds.h"
 #include "modules.h"
 
+#include "os/work_queue.h"
+
+#include "FreeRTOS.h"
+#include "timers.h"
+
 #include <math.h>
 
-uint8_t _personal_state_enabled   = 0;
-uint8_t personal_state            = STATE_NONE;
-uint8_t personal_state_persistent = 0;
+static uint8_t _personal_state_enabled   = 0;
+static uint8_t personal_state            = STATE_NONE;
+static uint8_t personal_state_persistent = 0;
+
+static int led_animation_ticks = 0;
+static int led_animation_state = 0;
 
-int led_animation_ticks = 0;
-int led_animation_state = 0;
+static TimerHandle_t led_timer;
+static StaticTimer_t led_timer_buffer;
+static void worktick(void *data);
+
+static const int led_animation_rate = 1000 / 25; /* 25Hz -> 40ms*/
 
 int personal_state_enabled()
 {
 	return _personal_state_enabled;
 }
 
+static void tick(TimerHandle_t xTimer)
+{
+	workqueue_schedule(worktick, NULL);
+}
+
 int epic_personal_state_set(uint8_t state, bool persistent)
 {
 	if (state > STATE_CAMP)
@@ -30,7 +46,29 @@ int epic_personal_state_set(uint8_t state, bool persistent)
 	_personal_state_enabled   = (state != STATE_NONE);
 	personal_state_persistent = persistent;
 
-	if (was_enabled && !_personal_state_enabled) {
+	if (!was_enabled && _personal_state_enabled) {
+		// Activate
+		if (!led_timer) {
+			led_timer = xTimerCreateStatic(
+				"personal state",
+				led_animation_rate / portTICK_PERIOD_MS,
+				pdTRUE,
+				NULL,
+				tick,
+				&led_timer_buffer
+			);
+			// since &poll_timer_buffer is not NULL, xTimerCreateStatic should allways succeed, so
+			// we don't need to check for poll_timer being NULL.
+		}
+
+		if (xTimerIsTimerActive(led_timer) == pdFALSE) {
+			xTimerStart(led_timer, 0);
+		}
+
+	} else if (was_enabled && !_personal_state_enabled) {
+		// Deactivate
+		xTimerStop(led_timer, 0);
+		// TODO: we might need a lock here to avoid a race condition
 		leds_prep(PERSONAL_STATE_LED, 0, 0, 0);
 		epic_leds_update();
 	}
@@ -48,19 +86,15 @@ int epic_personal_state_is_persistent()
 	return personal_state_persistent;
 }
 
-void vLedTask(void *pvParameters)
+static void worktick(void *data)
 {
-	const int led_animation_rate = 1000 / 25; /* 25Hz -> 40ms*/
-	while (1) {
 	if (_personal_state_enabled) {
 		led_animation_ticks++;
 		if (personal_state == STATE_NO_CONTACT) {
 			leds_prep(PERSONAL_STATE_LED, 255, 0, 0);
 		} else if (personal_state == STATE_CHAOS) {
 			if (led_animation_state == 0) {
-					leds_prep(
-						PERSONAL_STATE_LED, 0, 0, 255
-					);
+				leds_prep(PERSONAL_STATE_LED, 0, 0, 255);
 				if (led_animation_ticks >
 				    (200 / led_animation_rate)) {
 					led_animation_ticks = 0;
@@ -74,9 +108,7 @@ void vLedTask(void *pvParameters)
 					led_animation_state = 2;
 				}
 			} else if (led_animation_state == 2) {
-					leds_prep(
-						PERSONAL_STATE_LED, 0, 0, 255
-					);
+				leds_prep(PERSONAL_STATE_LED, 0, 0, 255);
 				if (led_animation_ticks >
 				    (1000 / led_animation_rate)) {
 					led_animation_ticks = 0;
@@ -92,9 +124,7 @@ void vLedTask(void *pvParameters)
 			}
 		} else if (personal_state == STATE_COMMUNICATION) {
 			if (led_animation_state == 0) {
-					leds_prep(
-						PERSONAL_STATE_LED, 255, 255, 0
-					);
+				leds_prep(PERSONAL_STATE_LED, 255, 255, 0);
 				if (led_animation_ticks >
 				    (1000 / led_animation_rate)) {
 					led_animation_ticks = 0;
@@ -115,13 +145,9 @@ void vLedTask(void *pvParameters)
 				1.0f,
 				fabs(sin(
 					led_animation_ticks /
-						(float)(1000 /
-							led_animation_rate))));
+					(float)(1000 / led_animation_rate))));
 		}
 
 		epic_leds_update();
 	}
-
-		vTaskDelay(led_animation_rate / portTICK_PERIOD_MS);
-	}
 }