hal_signal_new, hal_signal_delete, hal_link, hal_unlink − Manipulate HAL signals
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int hal_signal_new(const char *signal_name, hal_type_t type) | |
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int hal_signal_delete(const char *signal_name) | |
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int hal_link(const char *pin_name, const char *signal_name) | |
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int hal_unlink(const char *pin_name) |
signal_name
The name of the signal
pin_name
The name of the pin
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type |
The type of the signal, as specified in hal_type_t(3hal). |
hal_signal_new creates a new signal object. Once a signal has been created, pins can be linked to it with hal_link. The signal object contains the actual storage for the signal data. Pin objects linked to the signal have pointers that point to the data. ’name’ is the name of the new signal. If longer than HAL_NAME_LEN it will be truncated. If there is already a signal with the same name the call will fail.
hal_link links a pin to a signal. If the pin is already linked to the desired signal, the command succeeds. If the pin is already linked to some other signal, it is an error. In either case, the existing connection is not modified. (Use ’hal_unlink’ to break an existing connection.) If the signal already has other pins linked to it, they are unaffected - one signal can be linked to many pins, but a pin can be linked to only one signal.
hal_unlink unlinks any signal from the specified pin.
hal_signal_delete deletes a signal object. Any pins linked to the object are unlinked.
Returns a HAL status code.
hal_type_t(3hal)