Could someone explain this code that sets up the software serial port data rate?

Question

I understand most of it. The part I don't understand is the is the code in for void loop. How does that set the data rate for the software serial port? I thought mySerial.begin(9600) did that? Please help.

#include <SoftwareSerial.h>
SoftwareSerial mySerial(2, 3); // RX, TX
void setup()
{
 // Open serial communications and wait for port to open:
 Serial.begin(9600);
 while (!Serial) {
 ; // wait for serial port to connect. Needed for Leonardo only
 }
 Serial.println("Goodnight moon!");
 // set the data rate for the SoftwareSerial port
 mySerial.begin(9600);
 // set master
 mySerial.print("AT+ROLE1");
 delay(10000);
}
void loop() // run over and over
{
 // set the data rate for the SoftwareSerial port
 mySerial.print("test I am master ");
 delay(10000);
 ***if (mySerial.available())
 Serial.write(mySerial.read());
 if (Serial.available())
 mySerial.write(Serial.read());***
}

• Juraj: it is just a wrong placed comment :-)
• Juraj: are you asking about the code highlighted with ***?

Answer 1

You're confusing "data rate" with "baud rate".

The baud rate is the speed at which bytes are transmitted over the wires, and is set with mySerial.begin(9600);.

The data rate is the speed at which data is sent over the serial port, and that is set by the delay(10000); which dictates how often "test I am master " is sent and any incoming data is checked for and echoed.

Answer 2

The void loop

while(!Serial) {
;
}

simply wait for the serial port to be ready to transmite/receive data. Otherwise, your first Serial.print will be lost.

You can omit it if you don't plan to transmit anything during the first second or two in your sketch.