FreeRTOS Utilities

Data Structures
struct	rtos_instance_t
	Instance of a FreeRTOS task. More...

Enumerations
enum	rtos_event_t { RESEND_SENSOR = 0 , RESEND_IMAGE , RESEND_VIDEO }
	Event types posted to the memory event queue. More...

Functions
BaseType_t	task_create (TaskFunction_t pxTaskCode, rtos_instance_t *inst, void *const pvParameters)
	Create a FreeRTOS task using the provided instance parameters.
void	log_watermark (const rtos_instance_t *const inst)
	Log the high-water mark (stack usage in bytes) of a FreeRTOS task.
void	log_info (const rtos_instance_t *const inst)
	Log general task information in a human-readable way.
pal_err_t	sensor_queues_init (void)
	Create and initialize all sensor measurement queues.
pal_err_t	system_queues_init (void)
	Create and initialize all system queues.

Sensor Queues
FreeRTOS queues carrying measurements from each sensor task.
QueueHandle_t	queue_scd30
	SCD30 measurement queue.
QueueHandle_t	queue_veml7700
	VEML7700 measurement queue.
QueueHandle_t	queue_bme280
	BME280 measurement queue.

System Queues
FreeRTOS queues used by the aggregation, packet and memory tasks.
QueueHandle_t	queue_sens_agg
	Aggregated sensor payload queue.
QueueHandle_t	queue_pkt_tx
	New outgoing packets queue.
QueueHandle_t	queue_pkt_rx
	Inbound packet queue.
QueueHandle_t	queue_pkt_retx
	Stored outgoing packet queue.
QueueHandle_t	queue_mem_evt
	Memory task event queue.

Core Definitions
CPU core identifiers
#define	CORE0   (0)
	CPU core 0.
#define	CORE1   (1)
	CPU core 1.

General Macros
#define	WORD_LEN_BYTE   (4)
	Word length in bytes.
#define	BASIC_QUEUE_DEPTH   (5)
	Default number of items a queue can hold.
#define	SENSOR_RESEND_QUEUE_DEPTH   (32)
	Depth for the sensor data retransmission queue.
#define	NOT_SET   (255)
	Sentinel value for uninitialized fields.

Detailed Description

Copyright

Copyright (c) 2026 Adrien Chevrier. Under AGPL-3.0-or-later license.

A collection of useful ESP-IDF FreeRTOS wrappers.

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Data Structure Documentation

rtos_instance_t

struct rtos_instance_t

Instance of a FreeRTOS task.

Stores the task handle and its configuration parameters.

Data Fields
const BaseType_t	CORE	CPU core for pinning the task.
const UBaseType_t	PRIORITY	Task priority.
const uint32_t	STACK_SIZE	Task stack size in words.
const char *const	TAG	Tag used for logging.
TaskHandle_t	task_handle	FreeRTOS task handle.

Macro Definition Documentation

BASIC_QUEUE_DEPTH

#define BASIC_QUEUE_DEPTH   (5)

Default number of items a queue can hold.

CORE0

#define CORE0   (0)

CPU core 0.

CORE1

#define CORE1   (1)

CPU core 1.

NOT_SET

#define NOT_SET   (255)

Sentinel value for uninitialized fields.

SENSOR_RESEND_QUEUE_DEPTH

#define SENSOR_RESEND_QUEUE_DEPTH   (32)

Depth for the sensor data retransmission queue.

WORD_LEN_BYTE

#define WORD_LEN_BYTE   (4)

Word length in bytes.

Enumeration Type Documentation

rtos_event_t

enum rtos_event_t

Event types posted to the memory event queue.

Enumerator
RESEND_SENSOR	Request to transmit a stored sensor payload.
RESEND_IMAGE	Request to transmit a stored image.
RESEND_VIDEO	Request to transmit a stored video clip.

Function Documentation

log_info()

void log_info

(

const rtos_instance_t *const

inst

)

Log general task information in a human-readable way.

The following information is logged:

• Core ID.
• Current state.
• Current priority level.
• Current high-water mark.

Parameters

inst	Pointer to the rtos_instance_t structure.

Note

Pass NULL if calling this function from within the task itself.

log_watermark()

void log_watermark

(

const rtos_instance_t *const

inst

)

Log the high-water mark (stack usage in bytes) of a FreeRTOS task.

Uses FreeRTOS uxTaskGetStackHighWaterMark() internally.

See also

uxTaskGetStackHighWaterMark() from FreeRTOS for more details.

Parameters

inst	Pointer to the rtos_instance_t structure.

Note

Pass NULL if calling this function from within the task itself.

sensor_queues_init()

pal_err_t sensor_queues_init

(

void

)

Create and initialize all sensor measurement queues.

Initializes the following queues:

• queue_scd30 to hold sensor payload part items of type scd30_meas_t.
• queue_veml7700 to hold sensor payload part items of type veml7700_meas_t.
• queue_bme280 to hold sensor payload part items of type bme280_meas_t.

All queues can hold BASIC_QUEUE_DEPTH items.

See also

payload_utils.h for payload item types.

Return values

PAL_OK	On success.
PAL_ERR_INVALID_ARG	One or more queues could not be created.

system_queues_init()

pal_err_t system_queues_init

(

void

)

Create and initialize all system queues.

Initializes the following queues:

• queue_sens_agg to hold sensor paylaod items of type sensor_payload_t.
• queue_pkt_tx to hold packet items of type packet_t.
• queue_pkt_rx to hold packet items of type packet_t.
• queue_pkt_retx to hold packet memory indexes of type uint8_t.
• queue_mem_evt to hold RTOS event items of type rtos_event_t.

Queues can hold BASIC_QUEUE_DEPTH items, except queue_pkt_retx which is of depth SENSOR_RESEND_QUEUE_DEPTH.

See also

payload_utils.h for payload item types and packet_utils.h for packet items type.

Return values

PAL_OK	On success.
PAL_ERR_INVALID_ARG	One or more queues could not be created.

task_create()

BaseType_t task_create	(	TaskFunction_t	pxTaskCode,
		rtos_instance_t *	inst,
		void *const	pvParameters )

Create a FreeRTOS task using the provided instance parameters.

Uses FreeRTOS xTaskCreatePinnedToCore() internally.

See also

xTaskCreatePinnedToCore() from FreeRTOS for more details.

Parameters

[in]	pxTaskCode	Pointer to the task function.
[in,out]	inst	Pointer to a preconfigured rtos_instance_t structure.
[in]	pvParameters	Parameters to pass to the task function.

Returns

Any BaseType_t value from xTaskCreatePinnedToCore().

Variable Documentation

queue_bme280

QueueHandle_t queue_bme280

extern

BME280 measurement queue.

queue_mem_evt

QueueHandle_t queue_mem_evt

extern

Memory task event queue.

queue_pkt_retx

QueueHandle_t queue_pkt_retx

extern

Stored outgoing packet queue.

queue_pkt_rx

QueueHandle_t queue_pkt_rx

extern

Inbound packet queue.

queue_pkt_tx

QueueHandle_t queue_pkt_tx

extern

New outgoing packets queue.

queue_scd30

QueueHandle_t queue_scd30

extern

SCD30 measurement queue.

queue_sens_agg

QueueHandle_t queue_sens_agg

extern

Aggregated sensor payload queue.

queue_veml7700

QueueHandle_t queue_veml7700

extern

VEML7700 measurement queue.