20-101-1051 Datasheet, PDF (31/165 Pages) List of Unclassifed Manufacturers – C-Programmable Core Module with NAND Flash Mass Storage and Ethernet

• SWITCHCHAR.C—This program transmits and then receives an ASCII string on Serial
Ports E and F. It also displays the serial data received from both ports in the STDIO
window.
To set up the Prototyping Board, you will need to tie
TxE and RxF together on the RS-232 header at J14, and
you will also tie RxE and TxF together as shown in the
diagram.
J14
TxE RxE GND TxF RxF 485+ GND 485–
Once you have compiled and run this program, press
and release S2 on the Prototyping Board to send a message from Serial Port E to Serial
Port F; press and release S3 on the Prototyping Board to send a message from Serial
Port F to Serial Port E. The data sent between the serial ports will be displayed in the
STDIO window.
Two sample programs, SIMPLE485MASTER.C and 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—the second system may be another
RCM3365/RCM3375, or it may be any Rabbit single-board computer or RabbitCore mod-
ule that supports RS-485 serial communication as long as you use the master or slave sam-
ple program associated with that board.
Before running either of these sample programs on the RCM3365/RCM3375 assembly,
make sure pins 1–2 and pins 5–6 are jumpered together on header JP5 to use the RS-485
bias and termination resistors. The sample programs use Serial Port C as the RS-485 serial
port, and they use PD7 to enable/disable the RS-485 transmitter.
The RS-485 connections between the slave and master devices are as follows.
• RS485+ to RS485+
• RS485– to RS485–
• GND to GND
• SIMPLE485MASTER.C—This program demonstrates a simple RS-485 transmission of
lower case letters to a slave. The slave will send back converted upper case letters back
to the master and display them in the STDIO window. Use SIMPLE485SLAVE.C to
program the slave—reset the slave before you run SIMPLE485MASTER.C on the
master.
• SIMPLE485SLAVE.C—This program demonstrates a simple RS-485 transmission of
lower case letters to a master. The slave will send back converted upper case letters
back to the master and display them in the STDIO window. Compile and run this pro-
gram on the slave before you use SIMPLE485MASTER.C to program the master.
3.2.4 Real-Time Clock
If you plan to use the real-time clock functionality in your application, you will need to set
the real-time clock. Set the real-time clock using the SETRTCKB.C sample program from
the Dynamic C SAMPLES\RTCLOCK folder, using the onscreen prompts. The RTC_
TEST.C sample program in the Dynamic C SAMPLES\RTCLOCK folder provides addi-
tional examples of how to read and set the real-time clock.
User’s Manual
25