Link switch and Antenna selector
Link switch input¶
The link switch input (LINK_SW) can be used to interface with a momentary (monostable) closing push button to facilitate a simple user interface. This is an alternative to using the SPI interface to integrate into a host device's menu system.
This signal shall be pulled to VDD using an external 4.7kΩ-10kΩ resistor to ensure proper function.
The switch input has multiple functions, please see the table below for details about the functions of the switch input.
| Function | Conditions |
|---|---|
| Link | Only for transmitters. Pull signal low (button pressed) for 0.1-1 second. |
| Unlink | Hold signal low (button pressed) for >3 seconds. |
| Change RX/TX mode | See Mode selection for more info |
| Change TX protocol | See Protocol selection for more info |
| Force driver update mode | Hold signal low (button pressed) during power on. |
Antenna selection¶
The antenna selection input can be used to select the required RF antenna for use on TiMo. This pin is internally pulled high, meaning the External U.FL/IPEX connector is the default option. This pin can be overridden by writing to the ANTENNA register. See page 19 for details.
| Function | Conditions |
|---|---|
| High Level (Logical 1) | External U.FL/IPEX connector (default) |
| Low Level (Logical 0) | Internal Chip Antenna |