Texas Instruments SWRU294, User Manual, Page: 20 / 57

SWRU294
Page 20/40
6.8 Buttons
There are 7 buttons on the SmartRF TrxEB. Status of BTN_LEFT, BTN_RIGHT, BTN_UP,
BTN_DOWN and BTN_SELECT can be read by the onboard MSP430. These buttons are
intended for user interfacing and development of demo applications.
The RESET MCU button resets the MSP430 MCU by pulling its reset line low (MCU_RESET_N).
The RESET USB button similarly resets the USB controller (pulling USB_RESET_N low). Note
that the standard firmware on the USB controller will reset the EM and MSP430 during startup, so
pushing the RESET USB button also resets the controller on the EM board and the MSP430.
6.9 LEDs
6.9.1 General Purpose LEDs
The four LEDs D3, D4, D5, D7 can be controlled from the onboard MSP430 and are suitable for
demo use and debugging. The LEDs are active low.
6.9.2 USB LED
LED D6 (USB LED) is controlled by the USB controller and is used to indicate the status of the
EB. The USB LED has several states, listed in Table 6.
USB LED state Description
OFF Power is turned off, the USB controller is in Disabled
Mode or the software on the USB controller is corrupt.
ON
SmartRF Mode: The standard firmware is running and
a RF-IC has been detected.
UART Mode: The standard firmware is running. The
USB LED is quickly toggled OFF/ON when UART traffic.
This is typically seen as slight variations in emitted
intensity.
BLINKING (100 ms ON
– 900 ms OFF)
SmartRF Mode: No RF-IC is detected.
BLINKING (1 Hz) The USB MCU has entered the boot recovery mode.
See chapter 11 for further details.
BLINKING (10 Hz) The bootloader on the USB MCU could not find a valid
application to boot. Basic USB services are available
and both SmartRF Studio and SmartRF Flash
Programmer can be used to program an application to
the USB controller’s flash. See chapter 11 for further
details.
Table 6
– USB LED state descriptions