SYNOPSIS
#include <hal.h>
int hal_pin_new_bool(int comp_id, hal_pdir_t dir, hal_bool_t *pin_ptr, rtapi_bool dflt, const char *fmt, ...);
int hal_pin_new_real(int comp_id, hal_pdir_t dir, hal_real_t *pin_ptr, rtapi_real dflt, const char *fmt, ...);
int hal_pin_new_sint(int comp_id, hal_pdir_t dir, hal_sint_t *pin_ptr, rtapi_sint dflt, const char *fmt, ...);
int hal_pin_new_uint(int comp_id, hal_pdir_t dir, hal_uint_t *pin_ptr, rtapi_uint dflt, const char *fmt, ...);
int hal_pin_new_port(int comp_id, hal_pdir_t dir, hal_port_t *pin_ptr, const char *fmt, ...);ARGUMENTS
- comp_id
-
HAL component identifier returned by an earlier call to hal_init(3).
- dir
-
The direction of the pin, from the viewpoint of the component. It may be one of
HAL_IN,HAL_OUT, orHAL_IO. Any number ofHAL_INorHAL_IOpins may be connected to the same signal, but at most oneHAL_OUTpin is permitted. A component may assign a value to a pin that isHAL_OUTorHAL_IO. Components may not assign a value to a pin that isHAL_IN. - pin_ptr
-
The address of the opaque pin data storage reference, which must lie within memory allocated by hal_malloc(3).
- dflt
-
The default assigned pin value when the pin is created.
- fmt, …
-
A printf-style format string and arguments
DESCRIPTION
The hal_pin_new_*() family of functions create a new pin object. The type of the pin corresponds to one of the hal_type_t(3) types. Once a pin has been created, it can be linked to a signal object using hal_link(3). A pin contains an opaque reference, which can be dereferenced the appropriate getter/setter. Pins of type HAL_IN only can use the appropriate getter hal_get_*(). Pins of type HAL_OUT and HAL_IO and use the getter and the setter hal_set_*(). Getting and settin a pin’s value will address the value of the signal if the pin is connected. If no signal is linked, it gets/sets a dummy signal.
There are functions for each of the data types that the HAL supports. Pins may only be linked to signals of the same type.
The hal_pin_new_port() functions is special in that it does not have a default. Exact two HAL_PORT port pins, one HAL_IN and one HAL_OUT, must be connected to a HAL_PORT type signal. You cannot call hal_set_p(3) or hal_get_p(3) on a HAL_PORT pin. A call to hal_set_s(3) on the port signal will set the queue size.
RETURN VALUE
Returns zero (0) on success, or a negative errno value on failure.
SEE ALSO
hal_param_new(3), hal_getter(3), hal_setter(3), hal_type_t(3), hal_pdir_t(3), hal_link(3)