SI4840-DEMO Datasheet, PDF (10/22 Pages) Silicon Laboratories – Si4840/44 DEMO BOARD USERS GUIDE

Si4840/44-DEMO
4. Operation
The Si4840/44-Demo Board, a complete analog tune and digital display radio, provides two major modes of
operation: Time Mode and FM/AM/SW Radio Mode.
4.1. Time Mode
Put 2 AAA batteries into the battery compartment. The board will automatically enter Time Mode and display the
time. The demo board display in Time Mode is illustrated in Figure 1.
4.1.1. Time Setting
The time default value is 00:00 and can be set to the correct time manually when needed.
1. In Time Mode, press the BASS/TMR button to enter the setting menu. The default is to set the minute item first.
Press this button again to select the hour item. The selected item flashes.
2. While the selected item is flashing, press the DOWN/VOL- and UP/VOL+ button to set the desired time.
3. When you have finished setting the time, press the BASS/TMR button to quit the setting menu. The MCU
automatically quits the setting menu if there is no operation within 2 seconds.
4.1.2. Alarm Setting
1. In Time Mode, press the TREBLE/AL button to enable or disable the alarm function, and enter the setting menu
automatically when the alarm is enabled. Once you have entered the setting menu, the default is to set the
minute item first. Press this button again to select the hour item. The selected item flashes.
2. While the selected item is flashing, press the DOWN/VOL- and UP/VOL+ button to set the desired time.
3. When you have finished the alarm setting, press the TREBLE/AL button to quit the setting menu. The MCU
automatically quits the setting menu if there is no operation within 2 seconds.
4. If the alarm is enabled and the alarm setting time is matched, the radio will be automatically turned on after the
buzzer sounds for 5 seconds.
5. The radio will be turned off and the demo board will go into sleep mode automatically if there is no operation on
the buttons within 15 minutes; if there is any operation on the buttons, the auto-sleep function will be disabled.
The radio keeps working throughout this time.
4.2. FM/AM/SW Radio Mode
In Time Mode, long press (hold time >1s) the POWER/BAND button or when the alarm time is reached, the device
will enter FM/AM/SW mode. The LCD displays the following information: band indicator, band frequency indicator,
stereo indicator, and sleep indicator in case radio is automatically turned on by the alarm.
The demo board display in FM/AM/SW Mode is illustrated in Figure 3.
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Rev 0.1