User`s manual

16 RabbitCore RCM2300
3.1.2 Serial Communication
The following sample programs can be found in the
SAMPLES\RCM2300 folder.
One sample programs, PUTS.C, is available to illustrate RS-232 communication. To run
thIs sample program, you will have to add an RS-232 transceiver such as the MAX232 at
location U2 and five 100 nF charge-storage capacitors at C3–C7 on the Prototyping
Board. Also install a 2 × 5 IDC header with a pitch of 0.1" at J6 to interface the RS-232
signals. The diagram shows the connections.
This program writes a null terminated string over Serial Port A, B, or C. Only Serial Port
B is accessible by using a 10-pin header to DB9 cable with header J6 on the Prototyping Board.
Use a serial utility such as HyperTerminal or Tera Term to view the string. Use the follow-
ing configuration for your serial utility.
Bits per second: 19200
Data bits: 8
Parity: None
Stop bits: 1
Flow control: None
To access Serial Port A or Serial Port C, change the 2 to 1 or 3 respectively in the follow-
ing line in the sample program.
#define SERIAL_PORT2
Once the sample program is running, you may use a 10-
pin header to DB9 cable (for example, Part No. 540-0009) to
connect header J6 to your PC COM port (you will have to
disconnect the programming cable from both the RCM2300
and the PC if you only have one PC COM port, then press the
RESET button on the Prototyping Board). Line up the
colored edge of the cable with pin 1 on header J6 as shown in
the diagram (pin 1 is indicated by a small square on the
Prototyping Board silkscreen).
MAX232
100 nF
storage
capacitors
ry
ON
J6
TxB
RxB
GND
Colored
edge
RxC
TxC