SI4840-DEMO Datasheet, PDF (11/22 Pages) Silicon Laboratories – Si4840/44 DEMO BOARD USERS GUIDE

Si4840/44-DEMO
Figure 3. LCD Display in FM Radio Mode
The demo board provides two methods to select the radio band. One is to use the slide switch (S2). The other is to
use the POWER/BAND push button. S14 determines which method is in use.
The demo board also provides two methods to set the band property. One is to use the tuner default values; the
other is to use the keypad to reconfigure the band property value via the MCU. S13 determines which method is in
use. If you use the tuner default values, the band property is fixed and cannot be reconfigured. Refer to section
“4.2.1. MCU Setting Band Property” for the operation details for setting the band property using the keypad.
To operate the demo board, follow these procedures:
1. According to the desired radio band selection method, set S14 to use the slide switch or push button.
2. According to the desired radio band property, set S13 to use tuner default values or reconfigure the band
property.
3. Hold the POWER/BAND push button (hold time >1s) or when the alarm time is reached, the device will enter
FM/AM/SW Radio Mode.
4. Use slide switch S2 or press the POWER/BAND push button to select the desired band.
5. Refer to section “4.2.1. MCU Setting Band Property” or section “4.2.2. MCU Setting Radio Working Mode” to
reconfigure the band property or radio working mode if necessary.
6. Rotate the turning wheel and find the desired radio station with the help of the LCD display and/or tuning
indicator D1.
7. Rotate the volume control wheel VR2 and/or press the DOWN/VOL- or UP/VOL+ button to get a comfortable
volume. Press the BASS/TMR or TREBLE/AL button to get the desired bass/treble level.
Notes:
 For FM listening, the earphone cable must be connected to the board when S12 is set to HP ANT or an external
antenna must be connected to the BNC connector when S12 is set to BNC.
 For AM listening, the ferrite antenna must be connected to the board and the S11 is set to Ferrite before turning
on the radio or switching the band to AM.
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