Rabbit RabbitCore RCM3000 Getting Started Manual page 25

•
SIMPLE3WIRE.C
communication. Lower case characters are sent by TxC, and are
received by RxB. The characters are converted to upper case and are
sent out by TxB, are received by RxC, and are displayed in the
Dynamic C
STDIO
To set up the Prototyping Board, you will need to tie TxB and RxC together on the
RS-232 header at J5, and you will also tie RxB and TxC together using the jumpers
supplied in the Development Kit as shown in the diagram.
•
SIMPLE5WIRE.C
with flow control on Serial Port C and data flow on Serial Port B.
To set up the Prototyping Board, you will need to tie TxB and RxB
together on the RS-232 header at J5, and you will also tie TxC and
RxC together using the jumpers supplied in the Development Kit as
shown in the diagram.
Once you have compiled and run this program, you can test flow con-
trol by disconnecting TxC from RxC while the program is running. Characters will no
longer appear in the
back to RxC.
—This program demonstrates transmits and then receives an ASCII
•
SWITCHCHAR.C
string on Serial Ports B and C. It also displays the serial data received from both ports
in the window.
STDIO
To set up the Prototyping Board, you will need to tie TxB and RxC
together on the RS-232 header at J5, and you will also tie RxB and
TxC together using the jumpers supplied in the Development Kit as
shown in the diagram.
Once you have compiled and run this program, press and release S2
and S3 on the Prototyping Board. The data sent between the serial ports will be dis-
played in the
STDIO
Two sample programs,
and
MASTER.C SIMPLE485SLAVE.C
are available to illustrate RS-485
master/slave communication. To run
these sample programs, you will need
a second Rabbit-based system with
RS-485, and you will also have to add
an RS-485 transceiver such as the
SP483E and bias resistors to the
RCM30/31/32XX Prototyping Board.
The diagram shows the connections.
You will have to connect PC0 and PC1 (Serial Port D) on the RCM30/31/32XX Proto-
typing Board to the RS-485 transceiver, and you will connect PD4 to the RS-485 trans-
ceiver to enable or disable the RS-485 transmitter.
Getting Started
—This program demonstrates basic RS-232 serial
window.
—This program demonstrates 5-wire RS-232 serial communication
window, and will display again once TxC is connected
STDIO
window.
SIMPLE485-
,
Vcc
DI
PC0
RO
PC1
RS-485
CHIP
DE
PD4
/RE
GND
RxC TxC
TxB RxB GND
RxC TxC
TxB RxB GND
RxC TxC
TxB RxB GND
Vcc
485+
681 W
bias
A
termi-
220 W
nation
B
bias
681 W
485–
J5
J5
J5
21