Assuming that the target hardware is something like an Arduino Mega with support for multiple hardware serial ports.
I'm trying to write a fairly simple terminal emulator to go between the principal (USB) serial port and an arbitrary secondary port, so that I can experiment with various devices that expect "Hayes-like" command sequences. What I was hoping to do was have a menu at the start of the run so that I could select the port plus possibly Baud rate etc.
The thread at Hardware Serial Port Referencing - Programming Questions - Arduino Forum from around 2013 has examples of using both a reference and a pointer to indicate one of the possible hardware serial ports. I can get the "pointer-style" code to work, but can't help but feel that it's rather "K&R"; I can't get the reference-style code to work, getting something like
terminal:50:17: error: 'mySerial' declared as reference but not initialized
HardwareSerial& mySerial;
^~~~~~~~
/usr/local/src/arduino-examples/terminal/terminal.ino: In function 'void loop()':
terminal:15:14: error: use of deleted function 'HardwareSerial& HardwareSerial::operator=(const HardwareSerial&)'
#define PORT Serial1
^~~~
/usr/local/src/arduino-examples/terminal/terminal.ino:56:16: note: in expansion of macro 'PORT'
mySerial = PORT;
^~~~
Is this "use of deleted function" error to be expected? What's best practice for this sort of thing these days?
My apologies if I've overlooked anything obvious, I'm no great devotee of C/C++ so there's a possibility that I quite simply haven't hit on the right bit of "Google-fu".
#define PORT Serial1
#define PORTNAME "Serial1"
#define BAUD 115200
#define ONLINE false
#include "board_info.h" // Relies on a pair of symlinks from .. to .
void setup() {
// put your setup code here, to run once:
Serial.begin(115200); // Note: some boards do not support 9600 Baud etc.
while (!Serial) ; // wait for serial port to connect. Needed for Native USB only
#ifdef board_info_h
BOARD_INFO(__FILE__ " " __DATE__ " " __TIME__);
#endif
Serial.print("Port: ");
Serial.print(PORTNAME);
Serial.print(", online: ");
if (ONLINE) {
Serial.print("yes, baud: ");
Serial.print(BAUD);
} else
Serial.print("no");
Serial.println();
}
HardwareSerial *mySerial;
void loop() {
// put your main code here, to run repeatedly:
if (ONLINE) {
mySerial = &PORT;
mySerial->begin(BAUD);
while (! mySerial) ;
}
char c;
while(true) {
while (mySerial->available()) {
c = mySerial->read();
Serial.write(c);
}
if (Serial.available()) {
c = Serial.read();
mySerial->write(c);
}
}
mySerial->end();
}
This does not compile with the errors given:
#define PORT Serial1
#define PORTNAME "Serial1"
#define BAUD 115200
#define ONLINE false
#include "board_info.h" // Relies on a pair of symlinks from .. to .
void setup() {
// put your setup code here, to run once:
Serial.begin(115200); // Note: some boards do not support 9600 Baud etc.
while (!Serial) ; // wait for serial port to connect. Needed for Native USB only
#ifdef board_info_h
BOARD_INFO(__FILE__ " " __DATE__ " " __TIME__);
#endif
Serial.print("Port: ");
Serial.print(PORTNAME);
Serial.print(", online: ");
if (ONLINE) {
Serial.print("yes, baud: ");
Serial.print(BAUD);
} else
Serial.print("no");
Serial.println();
}
HardwareSerial &mySerial = PORT;
void loop() {
// put your main code here, to run repeatedly:
if (ONLINE) {
mySerial = PORT;
mySerial.begin(BAUD);
while (! mySerial) ;
}
char c;
while(true) {
while (mySerial.available()) {
c = mySerial.read();
Serial.write(c);
}
if (Serial.available()) {
c = Serial.read();
mySerial.write(c);
}
}
mySerial.end();
}
/usr/local/src/arduino-examples/terminal/terminal.ino: In function 'void loop()':
terminal:15:14: error: use of deleted function 'HardwareSerial& HardwareSerial::operator=(const HardwareSerial&)'
#define PORT Serial1
^
/usr/local/src/arduino-examples/terminal/terminal.ino:49:16: note: in expansion of macro 'PORT'
mySerial = PORT;
^~~~
What I was hoping to do was start off with a menu including 1-2-3 to select the secondary port to be used and probably letters for Baud (sorry, bps) rate etc. All hack stuff that I've done plenty of times on other platforms.
Indeed, using a pointer works. But the link I cited in my second message Easy way to select Serial, Serial1, Serial2, etc.... - Programming Questions - Arduino Forum explicitly says that references work, so I'm interested to know whether that was wrong (when written) or if there's been some subsequent change in the compiler, the compilation options, or the Arduino class library which has broken it.
