task_definitions.md

Task Definitions

Calendar Sync Task

• Creates an MQTT Client, and connects
• Subscribes to applicable roommate calendar topics events. Callback sends result to a queue
• Updates app state with most recent calendar event list

UX Task

• Waits for user interaction events, calendar updates, or calendar event transitions and initiates updates to the LEDs accordingly

LED Control Task

• Maintains a steady state LED pattern
• Waits on a queue of either steady state pattern updates or sequence requests
• When a pattern update is received update app state and the LEDs
• When a sequence is received call the sequence functions (via func ptrs) to orchestrate the LEDs
• When sequence is finished update the LEDs with the steady state pattern again

Proposed data structures

// This is the type of object that would be sent to the LED Control Task message queue
struct led_control_request {
	enum led_control_request_type type;
	union {
		struct led_sequence sequence_request_data;
		struct led_state steady_state_update_request_data;
	}
}  

enum led_control_request_type { LED_CONTROL_SEQUENCE_REQUEST, LED_CONTROL_STEADY_STATE_REQUEST };

struct led_sequence {
	led_sequence_executor_func executor;       // Called in a loop to get the next LED state (frame) until return value is null
	led_sequence_state_init_func initializer;  // Called to get initial state for sequence 
	uint8_t max_frames;
}

typedef struct led_frame (*led_sequence_executor_func)(void *sequence_state);

typedef void *(*led_sequence_state_init_func)(void);  // Ideally, this should return a struct instead of void ptr...

struct led_state {
	uint32_t leds[NUM_LEDS];
};

struct led_frame {
	struct led_state new_state;
	uint8_t duration_ms
};