UM1537
Hardware layout and configuration
Doc ID 023059 Rev 1
15/52
2.7
RS-232, RS-485 and IrDA
The RS-232 (with hardware flow control CTS and RTS), RS-485 and IrDA communication is
supported by D-type 9-pin RS-232/RS-485 connectors CN7, and IrDA transceiver U1 which
is connected to USART1 of the STM32F051R8T6 on the STM320518-EVAL evaluation
board. The signal Bootloader_RESET (shared with the CTS signal) and Bootloader_BOOT0
(shared with the DSR signal) are added to the RS-232 connector CN7 for ISP support.
Table 10.
RS-232 and IrDA related jumpers
Jumper
Description
JP3
RS232_RX is connected to the RS-232 transceiver and RS-232 communication is
enabled when JP3 is set as shown (default setting):
RS485_RX is connected to the RS-485 transceiver and RS-485 communication is
enabled when JP3 is set as shown:
IrDA_RX is connected to the IrDA transceiver and IrDA communication is enabled
when JP3 is set as shown:
JP4
PA11 is connected to the RS-232 transceiver as RS232_CTS when JP4 is set as
shown (default setting):
PA11 is connected to the HDMI_Sink connector as HPD when JP4 is set as shown:
RS
232_RX
RS
485_RX
Ir
DA
_
R
X
RS232_RX
RS485_RX
Ir
D
A
_
R
X
RS
232_RX
RS
485_RX
Ir
D
A
_
R
X
3
2
1
3
2
1