As noted earlier, RELAY_OFF needs a defined value.
Note, rather than using clumsy list of #define statements to define a bunch of integer constants, you can use C's enum declaration to define them, as shown in the following sketch, which produces the output
Relay 1 should be OFF
Relay 2 should be OFF
Relay 3 should be OFF
Relay 4 should be OFF
Relay 5 should be OFF
Relay 6 should be OFF
Relay 7 should be OFF
Relay 8 should be OFF
when it is run.
#include <Streaming.h>
// Arduino Digital I/O pin numbers for UNO R3
enum { Relay1=2, Relay2=3, Relay3=4, Relay4=5, Relay5=7, Relay6=8,
Relay7=9, Relay8=10, Relay9=11, Relay10=12, Relay11=13,
Relay12=A0, Relay13=A1, Relay14=A2, Relay15=A3, Relay16=A4};
int relays[] = {Relay1,Relay2,Relay3,Relay4,Relay5,Relay6,Relay7,Relay8};
// Number of relays in the array
enum { maxRelayCount = sizeof relays / sizeof relays[0] };
enum { RELAY_OFF = HIGH }; // Set LOW or HIGH as appropriate
char rx_byte = 0;
void setup() { // Initialize variables and settings
Serial.begin(9600);
//Set pins to OFF & declare pins as OUTPUTS
for(int i = 0; i < maxRelayCount; ++i) {
digitalWrite(relays[i], RELAY_OFF);
pinMode(relays[i], OUTPUT);
// Serial.print("Relay " +[i] + " set HIGH and as OUTPUTS");
Serial << "Relay " << i+1 << " should be OFF" << endl;
}
// Check that all relays are inactive at Reset
delay(4000);
}
void loop() {}
Note, the Streaming.h library adds some “syntactic sugar” to Arduino C. At compile time it converts C++-like << Serial stream operators to Serial.print statements, without increasing code size. You can install it by unzipping Streaming5.zip from arduiniana.org in your sketchbook/libraries directory..
