PIR Motion Sensor

Device driver interface for the PIR motion sensor. More...

Detailed Description

Device driver interface for the PIR motion sensor.

Topics
	PIR Motion Sensor driver compile configuration

Files
file	pir.h
	Device driver interface for the PIR motion sensor.
file	pir_params.h
	Default configuration for PIR devices.

Data Structures
struct	pir_params_t
	Parameters needed for device initialization. More...
struct	pir_t
	device descriptor for a PIR sensor More...

Enumerations
enum	{ PIR_OK = 0 , PIR_NOGPIO = -1 , PIR_NOTHREAD = -2 , PIR_TIMEERR = -3 }
	PIR specific return values. More...
enum	pir_event_t { PIR_STATUS_ACTIVE = PIR_MSG_T_STATUS_START , PIR_STATUS_INACTIVE }
	event type for a PIR sensor More...

Functions
int	pir_init (pir_t *dev, const pir_params_t *params)
	Initialize a PIR motion sensor.
pir_event_t	pir_get_status (const pir_t *dev)
	Read the current status of the motion sensor.
int	pir_get_occupancy (pir_t *dev, int16_t *occup)
	Read OCCUPANCY value.
int	pir_register_thread (pir_t *dev)
	Register a thread for notification when state changes on the motion sensor.

Enumeration Type Documentation

anonymous enum

anonymous enum

PIR specific return values.

Enumerator
PIR_OK	everything went as expected
PIR_NOGPIO	errors while initializing the GPIO
PIR_NOTHREAD	errors while registering the thread
PIR_TIMEERR	errors while getting the time information

Definition at line 35 of file pir.h.

pir_event_t

enum pir_event_t

event type for a PIR sensor

Enumerator
PIR_STATUS_ACTIVE	motion was detected
PIR_STATUS_INACTIVE	no motion is detected

Definition at line 78 of file pir.h.

Function Documentation

pir_get_occupancy()

int pir_get_occupancy	(	pir_t *	dev,
		int16_t *	occup )

Read OCCUPANCY value.

Parameters

[in]	dev	device descriptor of the PIR motion sensor to read from
[out]	occup	occupancy ratio [in 100 * percentage] The value is renewed when it is read. So it is percentage of occupancy since the last read.

Returns

0 on success,

-1 on errors,

pir_get_status()

pir_event_t pir_get_status

(

const pir_t *

dev

)

Read the current status of the motion sensor.

Parameters

[in]

dev

device descriptor of the PIR motion sensor to read from

Returns

1 if motion is detected, 0 otherwise

pir_init()

int pir_init	(	pir_t *	dev,
		const pir_params_t *	params )

Initialize a PIR motion sensor.

The PIR motion sensor is interfaced by a single GPIO pin, specified by gpio.

Note

The sensor needs up to a minute to settle down before meaningful measurements can be made.

Parameters

[out]	dev	device descriptor of an PIR sensor
[in]	params	parameters of the PIR sensor

Returns

0 on success

-1 on error

pir_register_thread()

int pir_register_thread

(

pir_t *

dev

)

Register a thread for notification when state changes on the motion sensor.

Note

This configures the gpio device for interrupt driven operation.

Parameters

[in]

dev

device descriptor of the PIR motion sensor to register for

Returns

0 on succuess,

-1 on internal errors,

-2 if another thread is registered already