Using HC-08 bluetooth module with arduino

Question

I have an arduino mega 2560 and a recently purchased HC-08 module and the connection is as the following:

Arduino | HC-08

VCC - VCC

GND - GND

14TX3 - TXD

15TX3 - RXD

When I power up the arduino it shows that flashing light and I am able to see it on my android phone but would only reject the connection every time I tried to pair. Also I am not able to send or receive any data from it at all, here is my code:

#include <SoftwareSerial.h>
SoftwareSerial hc08(15,14) // RX pin, TX pin;
void setup(){
 //Initialize Serial Monitor
 Serial.begin(9600);
 Serial.println("ENTER AT Commands:");
 //Initialize Bluetooth Serial Port
 hc08.begin(9600);
}
void loop(){
 //Write data from HC08 to Serial Monitor
 if (hc08.available()){
 Serial.println("Reading from bluetooth");
 Serial.write(hc08.read());
 }
 
 //Write from Serial Monitor to HC08
 if (Serial.available()){
 Serial.println("Writing to bluetooth");
 hc08.write(Serial.read());
 } 
}

I'd really appreciate help on how to get it working.

• Majenko: Don't use SoftwareSerial when you're using the hardware serial pins. For TX3/RX3 use Serial3. In fact, on the 2560 don't use SoftwareSerial at all - there's only certain select pins it will work on.
• Wool: Could you send a link to any documentation of this so I can see how to use Serial3
• Wool: I've now seen I can just use Serial1, 2 or 3 just like I would use Serial. Thanks
• Wool: But there still is the problem with the pairing being rejected.
• Majenko: But now you should be able to see and control the HC-08 through the Arduino to configure the pairing - however that's done on that board (I've never used one).

Answer 1

void setup(){
 //Initialize Serial Monitor
 Serial.begin(9600);
 Serial.println("ENTER AT Commands:");
 //Initialize Bluetooth Serial Port
 Serial3.begin(9600);
}
void loop(){
 //Write data from HC08 to Serial Monitor
 if (Serial3.available()){
 Serial.println("Reading from bluetooth");
 Serial.write(Serial3.read());
 }
 
 //Write from Serial Monitor to HC08
 if (Serial.available()){
 Serial.println("Writing to bluetooth");
 Serial3.write(Serial.read());
 } 
}

• Wool: ALSO: the HC-08 uses BLE, unlike the HC-05 and HC-06 and so won't exactly connect through the phone's system bluetooth settings.

Answer 2

I think this is the problem on the hardware setting. It should be: Arduino | HC-08

VCC - VCC

GND - GND

14RX3 - TXD

15TX3 - RXD

Variable declare: SoftwareSerial hc08(14,15) // RX pin, TX pin;