Rabbit RCM3365 User Manual

Contents

Rabbit RCM3365 User Manual Manual pdf 31 page image

User’s Manual 25• SWITCHCHAR.C—This program transmits and then receives an ASCII string on SerialPorts E and F. It also displays the serial data received from both ports in the STDIOwindow.To set up the Prototyping Board, you will need to tieTxE and RxF together on the RS-232 header at J14, andyou will also tie RxE and TxF together as shown in thediagram.Once you have compiled and run this program, pressand release S2 on the Prototyping Board to send a message from Serial Port E to SerialPort F; press and release S3 on the Prototyping Board to send a message from SerialPort F to Serial Port E. The data sent between the serial ports will be displayed in theSTDIO window.Two sample programs, SIMPLE485MASTER.C and SIMPLE485SLAVE.C, are availableto illustrate RS-485 master/slave communication. To run these sample programs, you willneed a second Rabbit-based system with RS-485—the second system may be anotherRCM3365/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-485bias and termination resistors. The sample programs use Serial Port C as the RS-485 serialport, 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 oflower case letters to a slave. The slave will send back converted upper case letters backto the master and display them in the STDIO window. Use SIMPLE485SLAVE.C toprogram the slave—reset the slave before you run SIMPLE485MASTER.C on themaster.• SIMPLE485SLAVE.C—This program demonstrates a simple RS-485 transmission oflower case letters to a master. The slave will send back converted upper case lettersback 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 ClockIf you plan to use the real-time clock functionality in your application, you will need to setthe real-time clock. Set the real-time clock using the SETRTCKB.C sample program fromthe 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.-./;";" ;5;5)*% )*%7