The UMSRadioTuner is a device specific object that controls an FM radio tuner. The tuner tunes stations between 88100 MHz and 107900 MHz. Stations are tuned in 200 MHz increments. This object is an interface to the tuner hardware. It will select a station, scan for string stations, return the status (tuned, stereo) of a station, and mute/unmute the audio. The actual volume of the audio is controlled through the master volume applet.
The RadioTuner hardware connects to the AUX1 input. This input must be active in order to hear the radio. AUX1 can be activated via master_settings at runtime. AUX1 is the same input as the CDROM. The CD audio is mixed with the radio audio.
You must call the open method to start tuning radio stations.
To learn more about the UMSRadioTuner object, see:
For introductory information, see Tuner Objects.
This method opens the Radio Tuner interface on the tuner device driver. This method must be called before other methods will work. After the interface is opened, the object will attempt to tune the default frequency (88100 KHz).
| Success | Call completed successfully. |
| InvalidArgument | Path was incorrect. |
| DeviceError | Call to driver failed. errno is set. |
This method closes the device driver.
| Success | Call completed successfully. |
| DeviceError | Method call to driver failed. errno is set. |
This method allows the caller to set the Radio Tuner to a specific frequency. The frequency is designated in kilohertz (for example, 93.7 FM is 93700). The valid frequency range is 88100 to 107900. This method returns the status, which is a combination of whether the frequency is tuned and whether it is stereo or mono.
| in long channel | The radio frequency in kilohertz. |
| out long status | The enumerated type tuner_status and the status of the frequency. Possible status states are NotTuned, TunedMono, and TunedStereo. |
This method returns the current channel and indicates whether the frequency is tuned.
| out long channel | The frequency is in kilohertz. The default channel is 88100 KHz. |
| out boolean Tuned | A value of True if the current station is in tune. |
This method increment or decrement the radio frequency by 200 KHz. The direction is set via the direction argument. The status feature is the same as that of the select_channel method.
| in UMSTuner_Direction direction | The direction to increment or decrement, either Up or Down. |
| out long status | The enumerated type tuner_status. |
This method scans to the next radio station. The direction of the scan (up or down) is determined by the direction argument. The locking strength is an integer between 0 and 3 that tells the tuner whether to stop on a frequency and call it tuned. A locking strength of 0 is Very Low and a strength of 3 is Very High. This call should be followed by a get_current_channel call to see where the tuner stopped and what status is (tuned, stereo, etc.). If the call is blocked, it does not return until the seek is complete. If no channels are tuned, the object resets the tuner to the default channel of 88100 KHz.
| Success | Call completed successfully. |
| DeviceNotOpen | Call to open was never made (or failed). |
| DeviceError | Call to driver failed. errno is set. |
This method sets and resets the mute on the radio.
| in UMSTuner_OnOff mute | Turns the mute On or Off. |
| Success | Call completed successfully. |
| DeviceNotOpen | Call to open was never made (or failed). |
| DeviceError | Call to driver failed. errno is set. |
This methods returns the current mute state.
| out UMSTuner_OnOff mute | The current mute state. The default value is Off. |
| Success | Call completed successfully. |
| NullPointer | The out parameter mute was not allocated properly. |
This method sets whether stereo or mono is requested. This might not be what is actually tuned, but it is used for the request to the hardware.
| in UMSTuner_OnOff stereo | Turns the stereo On or Off. The default value is On. |
| Success | Call completed successfully. |
This method returns the current stereo state. If you request stereo by using the set_stereo_audio call and the tuner is tuned to a mono station, the value of Off is returned on this call.
| out UMSTuner_OnOff stereo | Returns the state of the stereo as On or Off. |
| Success | Call completed successfully. |
| NullPointer | The out parameter was not allocated properly. |
This method sets a timeout value for use by the select_channel method. This value is the maximum time, in milliseconds (ms), that the driver waits on a PRESET call for the station to be tuned.
| in long timeout_ms | The timeout value in milliseconds that the select_channel method uses. |
| Success | Call completed successfully. |
| InvalidArgument | The timeout value was not reasonable (negative or > 60 seconds). |
This method returns the user-defined timeout value or the default value if the timeout value has not been set.
| out long timeout_ms | The timeout value in milliseconds that the select_channel method uses. |
| Success | Call completed successfully. |
| NullPointer | The out parameter was not allocated properly. |
For introductory information, see Tuner Objects.