nick gammon rs485 blocking

Projects Programming
1

i am using rs485 with multiple arduinos (1 master, 2 slaves). The code is working with a single master and slave setup but when i connect the second slave, the second slave hears nothing.. plxx guide me! The code is mentioned below. For the second arduino i used a second msg..

//Master sketch

#include "RS485_protocol.h"
#include <SoftwareSerial.h>

const byte ENABLE_PIN = 3;
const byte LED_PIN = 13;

SoftwareSerial rs485 (10, 11); // receive pin, transmit pin

// callback routines

void fWrite (const byte what)
{
rs485.write (what);
}

int fAvailable ()
{
return rs485.available ();
}

int fRead ()
{
return rs485.read ();
}

void setup()
{
Serial.begin(9600);
rs485.begin (9600);
pinMode (ENABLE_PIN, OUTPUT); // driver output enable
pinMode (LED_PIN, OUTPUT); // built-in LED
} // end of setup

byte old_level = 0;

void loop()
{

// read potentiometer
byte level = analogRead (0) / 4;
Serial.println(level);
delay(100);

// no change? forget it
if (level == old_level)
return;

// assemble message
byte msg [] = {
1, // device 1
2, // turn light on
level // to what level
};

byte msg1 [] = {
5, // device 2
2, // turn light on
level // to what level
};

// send to slave
digitalWrite (ENABLE_PIN, HIGH); // enable sending
sendMsg (fWrite, msg, sizeof msg);
digitalWrite (ENABLE_PIN, LOW); // disable sending
delay(1000);
digitalWrite (ENABLE_PIN, HIGH); // enable sending
sendMsg (fWrite, msg1, sizeof msg1);
digitalWrite (ENABLE_PIN, LOW); // disable sending
// Serial.print(fWrite);

// receive response
byte buf [10];
byte received = recvMsg (fAvailable, fRead, buf, sizeof buf);
// Serial.print(received);
digitalWrite (LED_PIN, received == 0); // turn on LED if error

// only send once per successful change
if (received)
old_level = level;
delay(2000);

//Slave sketch 1

#include <SoftwareSerial.h>
#include "RS485_protocol.h"

SoftwareSerial rs485 (7, 5); // receive pin, transmit pin
const byte ENABLE_PIN = 4;

void fWrite (const byte what)
{
rs485.write (what);
}

int fAvailable ()
{
return rs485.available ();
}

int fRead ()
{
return rs485.read ();
}

void setup()
{
Serial.begin(9600);
rs485.begin (9600);
pinMode (ENABLE_PIN, OUTPUT); // driver output enable
}

void loop()
{
byte buf [10];

byte received = recvMsg (fAvailable, fRead, buf, sizeof (buf));

if (received)
{
if (buf [0] != 2)
return; // not my device

if (buf [1] != 2)
return; // unknown command

byte msg [] = {
0, // device 0 (master)
3, // turn light on command received
};

delay (1); // give the master a moment to prepare to receive
digitalWrite (ENABLE_PIN, HIGH); // enable sending
sendMsg (fWrite, msg, sizeof msg);
delayMicroseconds (660);
digitalWrite (ENABLE_PIN, LOW); // disable sending

analogWrite (3, buf [2]); // set light level
} // end if something received

}

//Slave sketch 2

#include <SoftwareSerial.h>
#include "RS485_protocol.h"

SoftwareSerial rs485 (52, 53); // receive pin, transmit pin
const byte ENABLE_PIN = 4;

void fWrite (const byte what)
{
rs485.write (what);
}

int fAvailable ()
{
return rs485.available ();
}

int fRead ()
{
return rs485.read ();
}

void setup()
{
Serial.begin(9600);
rs485.begin (9600);
pinMode (ENABLE_PIN, OUTPUT); // driver output enable
}

void loop()
{
byte buf [10];

byte received = recvMsg (fAvailable, fRead, buf, sizeof (buf));

if (received)
{
if (buf [0] != 5)
return; // not my device

if (buf [1] != 2)
return; // unknown command

byte msg [] = {
0, // device 0 (master)
3, // turn light on command received
};

delay (1); // give the master a moment to prepare to receive
digitalWrite (ENABLE_PIN, HIGH); // enable sending
sendMsg (fWrite, msg, sizeof msg);
delayMicroseconds (660);
digitalWrite (ENABLE_PIN, LOW); // disable sending

analogWrite (51, buf [2]); // set light level
} // end if something received

} // end of loop

2

Please go back and edit your code to use code tags.

Next, you connect something, then the problem begins and we get no schematic?

3

Please modify your post and use the code button </> so your code looks like this and is easy to copy to a text editor. See How to use the Forum Your code is too long to study quickly without copying to a text editor.

What has Nick Gammon got to do with your problem?

...R