5
Serial Port – P3
The uEZGUI-EXP1 Board includes one female DB9 Serial Port Connector. This connector may operate in either RS232 or
RS485 (Full-duplex) interface levels depending on jumper settings of JP1 through JP4.
Jumpers JP1 – JP4 select the operating mode of the serial port;
Jumper 1-2 for RS232 levels, using UART0
Jumper 2-3 for RS485 levels, using UART1
When operating as RS232, the serial port may also be optionally configured to support ISP programming of the LPC1788
using FlashMagic Software. To enable ISP programming, jumper JP6 & JP7 must be loaded. Note that with these jumpers
loaded, operation of the LPC1788 may be affected by the RS232 interface signals. Refer to the FlashMagic user manual
for details.
Pin Number
RS485 Mode
RS232 Mode
1
No Connect
No Connect
2
485_RDB-
TXD (Output)
3
RXD (Input)
4
Signal Ground
No Connect
5
Signal Ground
Signal Ground
6
Signal Ground
Signal Ground
7
(OPT) RTS
8
485_TDB-
(OPT) CTS
9
(OPT 5V)
No Connect
Example Connections to the uEZGUI Boards
uEZGUI-1788-43WQR example connection with uEZGUI-EXP1
