SI4731-DEMO Datasheet, PDF (7/14 Pages) Silicon Laboratories – Si4731 DEMO BOARD USERS GUIDE

5. Human interface
There are 12 keys for controlling the demo board as shown in Figure 7:
Si4731-DEMO
MEM/AL/1
VOL+/2
M+/3
UP/4
MSCAN/5
VOL-/6
M-/7
DOWN/8
SET/9
BANDS/0
FUNC/DIGIT POWER
Figure 7. Human Interface Keys
Each key can have a different function under each operating condition:
 Calendar/Powerdown Mode: Radio function is disabled. LCD displays Calendar. Buttons can be used to set
time, etc.
 Radio AM/FM Mode: Tuner IC works in powerup mode (FM or AM). Radio function is enabled. LCD displays
the radio station parameters. Buttons are used to adjust radio settings.
 Digital Input Mode: Tuner IC works in powerup mode (FM or AM). Radio function is enabled. LCD displays the
radio station parameters. The buttons are used for direct digit input of station frequencies.
The functions of the buttons are summarized in Table 1:
Table 1. Key Function Description
Button/Mode
Calendar Mode
Tuner Off
Radio AM/FM Mode
Tuner On
MEM/AL/1
POWER
None
Enable radio
FM Mode: Used to adjust calendar using received RDS CT.
AM Mode: Used to automatically detect and set the channel spacing.
Disable radio function and enter calendar mode.
(Radio parameters will be saved to Flash).
SET
Enter calendar setup
menu
Enter radio setup menu.
(Parameter list in Table 2)
BANDS
UP/ Hold
DOWN ^{Time <}
0.5 s
0.5 s <
Hold
Time
< 3s
None
In setup menu,
change the current
calendar item by one
step.
Change between FM and AM band.
In setup menu, change the current parameter by one step.
In radio mode, tune up or down by one step.
Perform a station seek.
Hold
Time
> 3s
MSCAN
Fast parameter setting
None
Fast parameter setting.
Scan for all valid stations and save them to presets.
Note: Combination keying is entered and exited from Radio Mode by pressing and holding the SET key then pressing the
BANDS key. A combination of the SET and the MSCAN keys will cycle through the available display items.
Rev. 0.1
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