10
RS-232 interfaces
EVBlpc213x has two RS232 ports with DB-9 connector. TxD and RxD lines (and also RTS and CTS for port 1)
are led to jumpers through MAX3232 transceiver.
Stuffing jumpers causes connection of TxD and RxD signals to microcontrollers UART0 or UART1 ports.
RS232 signals can also be connected to any microcontroller’s pins with use of wires. Drawing below shows
implementation of RS232 ports.
13
10
11
8
12
9
14
7
C1+
1
C2+
4
GND
15
C1-
3
VCC
16
C2-
5
V-
6
V+
2
U1
MAX3232CSE
RX0
TX0
GND
GND
13
10
11
8
12
9
14
7
C1+
1
C2+
4
GND
15
C1-
3
VCC
16
C2-
5
V-
6
V+
2
U2
MAX3232CSE
RTS1
CTS1
RX1
TX1
RX1
CTS1
RTS1
TX1
GND
GND
1
6
2
7
3
8
4
9
5
J5
DB9F
+3.3V
+3.3V
+3.3V
+3.3V
+3.3V +3.3V
+3.3V
+3.3V
GND
GND
GND
1
6
2
7
3
8
4
9
5
J8
DB9F
GND
GND
GND
R
S
-2
32
0
R
S
-2
32
1
D15
CTS1
D16
RXD1
D17
RTS1
D18
TXD1
D13
RXD0
D14
TXD0
RS232_1_TXD
RS232_1_RTS
RS232_1_RXD
RS232_1_CTS
RS232_0_TXD
RS232_0_RXD
P0.0
P0.1
JP4
JP2
JP5
JP3
P0.8
P0.9
P0.10
P0.11
JP7
JP8
R27
220R
R28
330R
R29
220R
R30
220R
R31
330R
R32
330R
C9
100n
C6
100n
C7
100n
C5
100n
C4
100n
C2
100n
C3
100n
C1
100n
C10
100n
C14
100n
GND
GND
Figure 11
Connection of RS-232 ports to MMlpc213x.
1-Wire interface
The EVBlpc213x board has a 1-Wire bus connector. This connector can be used to connect e.g. a digital
DS1820 thermometer or Dallas/Maxim iButton reader from. The data signal has been applied to the J13
connector and designated as 1-W. It can be connected to any microcontroller lead-out by means of the
attached cable.
