RFD900ux Data Sheet
www.rfdesign.com.au
10
Last update 12/09/2019
25
SIRX_EXT
Input
UART Data In
3.3V
26
SITX_EXT
Output
UART Data Out
3.3V
27
SIRTS_EXT
Output
Request to send
3.3V
28
SICTS_EXT
Input
UART Clear to send
3.3V
29
GND
-
Ground
0V
30
GND
-
Ground
0V
In case there is a need to force the modem into boot mode, pull the SWO pin to the ground while
applying power. The on-board LED will become solid red when in bootloader mode.
