Here we create a basic Classic Bluetooth joypad for use on an Android device to control a microprocessor (Arduino) connected to a Bluetooth module. The app is fairly simply. There are 2 screens; the first is the main control panel and the second is a connection page.
When the CONNECT button on the main screen is clicked the second screen is opened to allow the user to connect to a Bluetooth device. The direction buttons, when clicked, transmit codes to the Arduino.
There are now many cheap and no brand HC-05 modules that use the 2.0-20100601 firmware and rather than keep making the same post for different modules I will have a single main post which, as I update and add to it, will become a single point of reference.
The 2.0-20100601 firmware is originally by HC/Wavesen and as the version number may suggest it is from 2010. I am not sure if other manufacturers use it under license or simply copy it since the genuine HC/Wavesen modules now use version 2.1 firmware.
HC-05
HC-05 with 2.0-20100601: AT Command Mode
HC-05 with 2.0-20100601: Connecting to an Arduino
HC-05 with 2.0-20100601: Initial Communications Test
HC-05 with 2.0-20100601: Main AT Commands
HC-05 with 2.0-20100601: AT Commands Dealing With Connections
HC-05 with 2.0-20100601: Making A Connection
Downloads
The HC-05 (ZG-B23090W) uses a regular Bluetooth smd module based on the csr BC417 with a MX 29LV800CBXBI-70G flash memory chip. It appears to be using the HC/Wavesen 2010 firmware and a Google search for “HC-05 2.0-20100601” should give you plenty to read, including some of my older posts.
I have received a few comments about HC-06 and HC-05 modules that use a new breakout board (new to me at least). When I received the first comment I hadn’t seen these modules, by the time I had received the 4th or 5th comment the modules were all over Taobao so I decided to order a few (2 x HC-06 and 2 x HC05). I have no real use for these except to see if they are different to previous versions.
HC-05s are Bluetooth 2.0/2.1 EDR devices that have a serial UART layer on top of the Bluetooth. The UART layer makes them easy to use but hides the Bluetooth functions from the user. This is good if all you want is to make 2 things talk to each other. The HC-05 has two modes of operation; AT command mode and transmission mode. When in AT command mode all data received over the serial UART connection is treated as a command, and when in transmission mode, all data received over the serial UART connection is treated as data.
When in communication mode, if there is an active connection the data is broadcast to the connected device. If not connected, the data, disappears in to some mysterious void.
The HC-05 can operate as either a slave or master device. Slave devices cannot initiate connections, they can only accept them. Master devices can initiate and (depending on the actual module) sometimes accept them. If you want to use the module with a mobile device such as an Android phone, the phone will be the master device and so the HC-05 will need to be the slave. If you want to link two HC-05s, one will need to be a master and the other one a slave.
The HC-06 (ZG-B23090W) uses a regular smd Bluetooth module based on the csr BC417 chip with a MX 29LV800CBXBI-70G flash memory chip. The firmware is well documented and a Google search for “HC-06 linvor V1.8” should get you more than a few hits.
I have received a few comments about HC-06 and HC-05 modules that use a new breakout board (new to me at least). When I received the first comment I hadn’t seen these modules, by the time I had received the 4th or 5th comment the modules were all over Taobao so I decided to order a few (2 x HC-06 and 2 x HC05). I have no real use for these except to see if they are different to previous versions.
The HC-06 is a Bluetooth 2.0/2.1 EDR device that has a serial UART layer on top of the Bluetooth. The UART layer makes them extremely easy to use but hides the Bluetooth functions from the user. This is good if all you want is to make 2 things talk to each other.
The HC-06 has 2 modes of operation; AT mode and transmission mode. When the modules are first powered on they go in to AT mode. Here AT commands can be entered via the wired serial connection. After a connection has been made the modules go in to transmission mode. Here everything the modules receives via the wired serial connection is sent to the connected device. At commands cannot be entered again until the connection is broken.
HC-06s are slave only modules and require a master device to make a connection. Slave devices cannot initiate a connection which means you cannot link 2 HC-06s together. The master module is the HC-05 which can be either slave or master. Since the price for the HC-05 and the HC-06 is basically the same I would suggest buying HC-05s and not HC-06s.
Since I first posted about the HM-10 the firmware has been updated many times and some of the commands have changed. Therefore, I decided to redo the guide. For the main article I am using modules with firmware 5.49 (regular) except the one I am using for the firmware update guide which started with v5.40 and become 5.47.
There have been several firmware updates since this guide was written, as of March 2020 the latest is v707.
Updated 2019-08-25
I thought it was time for a minor update.
The latest zs-040 HC-06 modules have an updated firmware, hc01.comV2.0. This firmware has the following defaults:
– baud rate = 9600
– password = 1234
– nl/cr line endings not required.
– AT commands are required to be in upper case
– Firmware version = hc01.comV2.0
– Name = HC-06
– No parity
– SLAVE mode
Since the Bluetooth hardware is the same as the previous zs-040 HC-06s the Bluetooth specs are also the same. Bluetooth 2.0 EDR, SSP.
These use a slightly different BT module than the other zs-040 boards and there is a blue LED at the top left of the daughter board.
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Updated 12.06.2016: Added example 2
In the Connecting 2 Arduinos by Bluetooth using a HC-05 and a HC-06: Pair, Bind, and Link post I explained how to connect a HC-05 to a HC-06 so that when powered they automatically made a connection. Here we look at using that connection to get Arduinos talking over Bluetooth. Before continuing you need to have the Arduinos and BT modules set up as per the previous post. Here I am using 2 HC-05s. One in master mode the other in slave mode. The setup process for the slave mode HC-05 is the same as the HC-06 in the previous post.
Updated: 21.07.2017
There are many very similar Bluetooth modules available and sometimes it can be difficult finding out, not only which one you have, but also how yo use them. Here I look at some of the modules I have and try to show the basic settings.
Getting Started
Connecting To A Computer
Android Apps
Bluetooth 2.0/2.1 EDR Modules
HC-06 (ZG-B23090W) Bluetooth 2.0 EDR modules
HC-05 (ZG-B23090W) Bluetooth 2.0 EDR modules
SPP-C HC-06 / BT06 HC-06
HC-06 zs-040 hc01.com v2.0
HC-05 zs-040 hc01.com V2.1
HC-05 FC-114 and HC-06 FC-114
HC-05 and HC-06 zs-040 Bluetooth modules
Bluetooth 4 / BLE Modules
HM-10
HM-11
BT05-A mini BLE Bluetooth V4.0 iBeacon
AT-09 Bluetooth V4.0 CC2541
In a previous post I showed how to connect an app inventor Android app to a Bluetooth module connected to an Arduino to control an LED. See Turning a LED on and off with an Arduino, a HC-06 and Android
A few people have asked how to make it so that the app auto-connect to the Arduino on start up and I thought I would offer my solution. This example adds to the previous guide.
Update 19.09.2015
The FC-114 boards I have have the Bolutek firmware. User DS has reported that he/she has FC-114 boards that have the linvorV1.8 firmware. So if the below does not work for you then check what firmware you have.
I may be missing something but I can not get the HC-05 FC-114 boards in to Master Mode and connect to other BT devices with just AT commands. The modules say they have accepted the commands, such as AT+ROLE1 but when I try to connect to other modules I get the error message “Can only be used in Lord Mode”.
The modules accept “AT+ROLE1” and report they have changed mode but they haven’t really.
In an earlier post I mentioned that it looks likes pin 27 or pin 28 has to be pulled HIGH to enter Master Mode and this does indeed seem to be the case. Everything I have tried without pulling the pin(s) HIGH has failed.
They reply with “OK” and if you interrogate with “AT+ROLE” they report “+ROLE=1” but they are actually still in Slave Mode.
Update 19.09.2015
The FC-114 boards I have have the Bolutek firmware. User DS has reported that he/she has FC-114 boards that have the linvorV1.8 firmware. So if the below does not work for you then check what firmware you have.
Since the HC-05 FC-114s and the HC-06 FC-11s share the same firmware the following should work on either module.
The default setting on start up is Slave Mode waiting for pairing or a connection and also accepting AT commands. This means it is fairly simply to start using AT commands.
I have just received some new HC-05 and HC-06 Bluetooth modules. These were sold as zs-040s which is the module I actually wanted but I received modules marked FC-114. They share the same breakout board as the zs-040 but have different pins soldered between the Bluetooth module and the breakout board and have a very different firmware.
The small push button switch still has traces to pin 34 and still pulls pin 34 HIGH, however, on the FC-114 boards, pin 34 is a regular IO pin and closing the button switch doesn’t do anything. On the zs-040 boards, closing the button switch and pulling pin 34 HIGH puts the modules in to AT mode. Since the FC-114 starts in AT mode this is no big loss.
It took me a while to figure out the differences.
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This post follows on from Arduino With HC-05 Bluetooth Module in Slave Mode
The STATE pin on the HC-05 zs050 board is connected to the LED 2 pin on the small bluetooth module and the LED 2 pin is used to indicate when there is an active connection. This means the Arduino can connect to the STATE pin and determine when we have a connection. The STATE pin is LOW when the HC-05 is not connected and HIGH when the HC-05 is connected.
As a quick visual indicator you can put a LED + suitable resistor on the STATE pin. When the module is connected the LED will light.
You can also use the Arduino to read the value of the STATE pin.
The Arduino Mega has 4 hardware serial channels so we do not need to use software serial, we can use one of the extra hardware serials to talk to the Bluetooth module. In the below example I using serial1 to talk to the HC-05.
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Updated on 06.08.2016
Here is an example of controlling the Arduino over Bluetooth using a HC-06 bluetooth module and an Android app. The example uses an Arduino Nano but other Arduinos will work just as well. A HC-05 module can be used stead of the HC-06.
The Android app was created in app inventor and the aia file can be downloaded at the bottom of the page.