User's Manual

BlueMod+C11/G2
Hardware Reference
www.stollmann.de Page 10 of 42
3.4 Serial Interface
The interface functionally corresponds to the norm V.24 / RS-232 but has TTL-level.
Transmission speeds 300 bps 921600 bps (asynchronous)
Character representation: 7 to 9 Bit, even, odd, mark, space or no Parity, 1, 1.5
or 2 stop bits
Half duplex or full duplex
Hardware flow-control (RTS/CTS)
Note: All signals of the serial interface are named according to the EIA232 DTE
definition.
3.4.1 RS-485 Support
For RS-485 support the serial interface has to be connected to an external Tran-
sceiver, we suggest the MAX3491E from Maxim Integrated Products, due to it sup-
ports full duplex transmissions.
UART_RX
UART_TX
BlueMod+C11/G2
Connections in Full Duplex Mode
D
R
RO
RE
DI
DE
GND
A
B
Z
Y
VCC
GND
2
3
4
5
14
6,7
9
10
11
12
+
+3,3V
MAX3491E
UART_CTS
GND