Hardware Description
10
SLLU250 – November 2016
Copyright © 2016, Texas Instruments Incorporated
BOOSTXL-RS232 BoosterPack™ Hardware
3.6
LED Description
For this BoosterPack, there are two LEDs per RS232 line (RTS1, RX1, CTS1, TX1) and one power
indication LED, see
. The LEDs serve as a reference when connecting the BoosterPack to a
LaunchPad and up to a RS232 serial port. A red LED for an RS232 line indicates negative voltage or a
LOW signal, while a green LED indicates positive voltage or a HIGH signal. This information is also
denoted next to each LED; a '+' sign for the green LED and a '-' sign for the red LED. Upon powering the
BoosterPack, the power LED will turn on and the driver and receiver line LEDs may also be on, depending
on what the board is connected to.
Since RS232 TX and RX lines sit at a LOW voltage level until data is transmitted or received, the red LED
for TX1 and RX1 on the board will be on until data is transmitted or received. While transmitting or
receiving, the green LED will blink for the line in use. End of transmission is indicated with just a red LED.
The RTS1 green LED will be on when a request-to-send signal is raised and the CTS1 green LED will be
on when the clear-to-send signal is raised. Otherwise, the red LEDs will be on.
Figure 10. RS232 LEDs
