I've tried several wiring configurations and example sketches, but I'm not able to get anything useful when it comes to rs485.
The latest example I followed is this guide
https://arduino-info.wikispaces.com/SoftwareSerialRS485Example
with two Megas and these rs485 boards...
http://www.ebay.com/itm/5PCS-MAX485-RS-485-Module-TTL-to-RS-485-module-for-Arduino-Raspberry-pi-N122-/401251155592?hash=item5d6c6ebe88:g:oR8AAOSwHnFVl81j
There is some debate about whether the A and B need to crossover. I think they would have to.
After following the example and trying the serial monitor at 4800 and 9600, the "master" mega shows up with
YourDuino.com SoftwareSerial remote loop example
Use Serial Monitor, type in upper window, ENTER
but then when I type in the window, I get gobblygook in the master serial monitor.
Over on the slave side, I get
SerialRemote
but nothing shows up on either serial monitor if I type over there.
For clarification, here's my code.
Master
/* YourDuino SoftwareSerialExample1
- Connect to another Arduino running "YD_SoftwareSerialExampleRS485_1Remote"
- Connect this unit Pins 10, 11, Gnd
- Pin 3 used for RS485 direction control
- To other unit Pins 11,10, Gnd (Cross over)
- Open Serial Monitor, type in top window.
- Should see same characters echoed back from remote Arduino
Questions: terry@yourduino.com
*/
/*-----( Import needed libraries )-----*/
#include <SoftwareSerial.h>
/*-----( Declare Constants and Pin Numbers )-----*/
#define SSerialRX 10 //Serial Receive pin
#define SSerialTX 11 //Serial Transmit pin
#define SSerialTxControl 3 //RS485 Direction control
#define RS485Transmit HIGH
#define RS485Receive LOW
#define Pin13LED 13
/*-----( Declare objects )-----*/
SoftwareSerial RS485Serial(SSerialRX, SSerialTX); // RX, TX
/*-----( Declare Variables )-----*/
int byteReceived;
int byteSend;
void setup() /****** SETUP: RUNS ONCE ******/
{
// Start the built-in serial port, probably to Serial Monitor
Serial.begin(9600);
Serial.println("YourDuino.com SoftwareSerial remote loop example");
Serial.println("Use Serial Monitor, type in upper window, ENTER");
pinMode(Pin13LED, OUTPUT);
pinMode(SSerialTxControl, OUTPUT);
digitalWrite(SSerialTxControl, RS485Receive); // Init Transceiver
// Start the software serial port, to another device
RS485Serial.begin(4800); // set the data rate
}//--(end setup )---
void loop() /****** LOOP: RUNS CONSTANTLY ******/
{
digitalWrite(Pin13LED, HIGH); // Show activity
if (Serial.available())
{
byteReceived = Serial.read();
digitalWrite(SSerialTxControl, RS485Transmit); // Enable RS485 Transmit
RS485Serial.write(byteReceived); // Send byte to Remote Arduino
digitalWrite(Pin13LED, LOW); // Show activity
delay(10);
digitalWrite(SSerialTxControl, RS485Receive); // Disable RS485 Transmit
}
if (RS485Serial.available()) //Look for data from other Arduino
{
digitalWrite(Pin13LED, HIGH); // Show activity
byteReceived = RS485Serial.read(); // Read received byte
Serial.write(byteReceived); // Show on Serial Monitor
delay(10);
digitalWrite(Pin13LED, LOW); // Show activity
}
}//--(end main loop )---
Slave
/* YourDuino SoftwareSerialExample1Remote
- Used with YD_SoftwareSerialExampleRS485_1 on another Arduino
- Remote: Receive data, loop it back...
- Connect this unit Pins 10, 11, Gnd
- To other unit Pins 11,10, Gnd (Cross over)
- Pin 3 used for RS485 direction control
- Pin 13 LED blinks when data is received
Questions: terry@yourduino.com
*/
/*-----( Import needed libraries )-----*/
#include <SoftwareSerial.h>
/*-----( Declare Constants and Pin Numbers )-----*/
#define SSerialRX 10 //Serial Receive pin
#define SSerialTX 11 //Serial Transmit pin
#define SSerialTxControl 3 //RS485 Direction control
#define RS485Transmit HIGH
#define RS485Receive LOW
#define Pin13LED 13
/*-----( Declare objects )-----*/
SoftwareSerial RS485Serial(SSerialRX, SSerialTX); // RX, TX
/*-----( Declare Variables )-----*/
int byteReceived;
int byteSend;
void setup() /****** SETUP: RUNS ONCE ******/
{
// Start the built-in serial port, probably to Serial Monitor
Serial.begin(9600);
Serial.println("SerialRemote"); // Can be ignored
pinMode(Pin13LED, OUTPUT);
pinMode(SSerialTxControl, OUTPUT);
digitalWrite(SSerialTxControl, RS485Receive); // Init Transceiver
// Start the software serial port, to another device
RS485Serial.begin(4800); // set the data rate
}//--(end setup )---
void loop() /****** LOOP: RUNS CONSTANTLY ******/
{
//Copy input data to output
if (RS485Serial.available())
{
byteSend = RS485Serial.read(); // Read the byte
digitalWrite(Pin13LED, HIGH); // Show activity
delay(10);
digitalWrite(Pin13LED, LOW);
digitalWrite(SSerialTxControl, RS485Transmit); // Enable RS485 Transmit
RS485Serial.write(byteSend); // Send the byte back
delay(10);
digitalWrite(SSerialTxControl, RS485Receive); // Disable RS485 Transmit
// delay(100);
}// End If RS485SerialAvailable
}//--(end main loop )---
Does anyone have a point in the right direction on this?
