Setup HC-05 and HC-06, for Wireless 'Number Invaders'

As an enhancement of my previous post -- 'Number Invaders' with Virtual 7 Segment Display -- the target for this post is to show how to make this very simple game wireless, with Bluetooth module like HC-05 / HC-06.

Changing the game's code to make use of Bluetooth is very easy; nevertheless, I will show how to setup and configure HC-05 / HC-06 first.

Although HC-05 and HC-06 are functionally similar, setting them up have some subtle differences. I hope this post will make the differents clear, and be helpful for seting up HC-05 / HC-06. What you need is a microcontroler board, like Arduino Nano, some wireings, and of cause a simple sketch to do the job.

Step 1: Connection Diagram

The concentration should simply be on connections between Arduino Nano and HC-05 (or HC-06)

Connect HC-05 VCC to Arduino Nano 5V.
Connect HC-05 GND to Arduino Nano GND.
Connect HC-05 TXD to Arduino Nano D2.
Connect HC-05 RXD to Arduino Nano D3.

The rest is just the wireings for the "Number Invaders" game, the same as mentioned in my previous post.

Step 2: The Sketch for Setting Up HC-05 / HC-06

// ***
// * notes for HC-06 / HC-08:
// * . default baud rate is 9600
// * . serial monitor needs no
// * notes for HC-05:
// * . need be in AT mode; need to hold its button while powering on; LED on HC-05 will flash slowly
// * . baud rate is 38400
// * . serial monitor needs NL and CR
// ***
#include <SoftwareSerial.h>
SoftwareSerial hc(2, 3);  // 2 => TX of HC; 3 => RX of HC
// for HC-6
//   9600: AT+BAUD4
//   57600: AT+BAUD7
//   115200: AT+BAUD8
//   arduino: AT+NAMEarduino
//   1234: AT+PIN1234
// for HC-05
//   get name: AT+NAME?
//   set name: AT+NAME=arduino
//   set password: AT+PSWD=1234
//   get baud: AT+UART? 
//   set baud: AT+UART=115200,0,0 
//   reset: AT+ORGL
// for HC-08 (set up like HC-06)
//  get info: AT+RX  
//  set name: AT+NAME=xxx
//  set baud: AT+BAUD=nnn 
//  reset: AT+RESET
//  reset to default: AT+DEFAULT
const unsigned long baud = 38400;  // default for HC-06 / HC-08 is 9600; for HC-05, set to 38400 (assume HC-05 in AT mode)
void setup() {
  // initialize Serial 
  Serial.begin(baud);
  Serial.println("Hello from Arduino. Please enter AT command:");
  // initialize HC06
  hc.begin(baud);
}
void loop() {
  // write data from HC06 to Serial
  if (hc.available()) {
    Serial.write(hc.read());
  }
  // write data from Serial to HC06
  if (Serial.available()) {
    hc.write(Serial.read());
  }  
}

If all the comments are removed, the sketch should be short. Moreover, the sketch should be good for both HC-05 and HC-06.

But do notice the variable baud. Make sure it is set to the correct value.

Step 3: Running of the Sketch for HC-05

Set the sketch's baud variable to 38400, which is the baud rate to use when HC-05 is in AT mode. Then, upload the sketch.
Put HC-05 in AT mode. To do this, press the button on HC-05 while powering the Arduino Nano / HC-05 up. When in AT mode, the LED on HC-05 should blink very slowly.
Use a serial monitor / terminal to connect to Arduino Nano. Make sure 1) the termainl is configured to use the baud rate 38400; and 2) make sure it is set to use CR and NL
Make connection.
Should see "Hello from Arduino. Please enter AT command". If not, reset Arduino Nano.
Enter "AT" to test if the connection is good. It should response with "OK".
To set name for HC-05, enter the AT command like "AT+NAME=Nano". It should response with "OK".
To check the name set is correct, enter the AT command "AT+NAME?". It should response with "+NAME:Nano".
To set HC-05 baud rate to 115200, enter the AT commant "AT+UART=115200,0,0". It should response with "OK".
To check the baud rate set, enter the AT command "AT+UART?". It should response with "+UART:115200,0,0".
That is it. Now, the attached HC-05 has a name, and is using the baud rate 115200.

Step 4: Running of the Sketch for HC-06

Set the sketch's baud variable to 9600 which is the default baud rate of HC-06. Note that after you changed the baud rate, this variable shoud match, if you need to re-run the sketch.
Use a serial monitor / terminal to connect to Arduino Nano. Make sure 1) the termainl is configured to use the baud rate 9600; and 2) make sure it is set to append nothing; i.e. no CR; no NL
Make connection.
Should see "Hello from Arduino. Please enter AT command". If not, reset Arduino Nano.
Enter "AT" to test if the connection is good. It should response with "OK".
To set name for HC-06, enter the AT command like "AT+NAMENano". It should response with "OKsetname".
To set HC-06 baud rate to 115200, enter the AT commant "AT+BAUD8". It should response with "OK115200".
That is it. Next time if you need to change it's setting, the baud rate will be 115200. Be reminded!

Step 5: Modify 'Number Invaders' Sketch for HC-05 / HC-06

In order to make use of HC-05 / HC-06 for bluetooth connection to DumbDisplay Android app, the 'Number Invaders' sketch (show in previous post), certainly need be modified, a tiny bit.

Simple replace 2 lines

#include "dumbdisplay.h"
DumbDisplay dumbdisplay(new DDInputOutput(115200));

with

#include "ssdumbdisplay.h"
DumbDisplay dumbdisplay(new DDSoftwareSerialIO(new SoftwareSerial(2, 3), 115200, true, 115200));

In order to change connection method, simply need to change IO object passed when create the DumbDisplay object.
For HC05 / HC06 attached to Arduino Nano, software serial is used. And here it is assumed the same pin assignments as described previously.
Note that the OTG connection mechanism is still enabled; due to how the last 2 arguments passed.