#36 Control your Arduino from your phone - HC06 Bluetooth module 

Just do it, Douglas! It's amazing when it all just comes together (ironically, even better when you've had a couple of speed bumps along the way!). Let me know how you get on. Thanks for posting.

Yes, I will be giving it a go Ralph, plus going through the rest of your videos as well. Loads of great stuff to learn. I already have a pretty good grasp of the basics of electronics, and happy to not have to re-invent the wheel, when I can buy these modules so cheaply. Thanks again for the tutorials. Great stuff.

The idea is to move away from AT commands, Dave, and use the inbuilt facilities within C++. If you follow this video _exactly_ then you will the _exact_ same results (sounds logical, right?) When you say you have Nanos with integrated BT, what are they? Got a link? Arduino are about to release new Nanos (June/July 2019) with this type of feature but I'm not aware of any others right now.

OMG you watched all 36 videos! I guess you must be a very keen Arduinite (or really, really bored!). But seriously, it's great that you would spend the time watching them all and I'm really glad it gave you some ideas and tips. The IDE I use (sometimes) is the Eclipse IDE for Arduino (it's used for much more than Arduino, but there is a special version for Arduino users: eclipse.baeyens.it/download.php) but I do warn you it may take a couple of hours to get it up and running the way you want to. That's after you've read umpteen forums and FAQ pages! I was going to do a video on it but realised it was not for noobs (I use Microsoft Visual Studio in my day job and the Eclipse IDE feels very familiar - but not for the fainthearted). But if you're interested have a go - you can always revert back to the standard IDE as I do. Thanks for your kind words and do spread the word and subscribe if you haven't already. Part 2 of the Android Bluetooth Phone Control for Arduino due to be published in a few days.

Here I am. Did the video help you, Marco?

Ralph S Bacon absolutely

Glad you liked it!

Glad you liked it, Shyam, and I will try to keep going. I'm up to video #156 now so you have some more to watch!

I reckon it should work just the same on an ESP32 as it does on an Arduino. Admittedly I do very differently on my Smart Heating Controller (Wi-Fi not BT) but I'm using my ESP32 as a web server and my phone purely as a browser interface. Hmm, thinking cap on!

@@RalphBacon thank you BT is new to me.

Glad you liked it!

I loved it actually I'm going to check out all your other content thank you so much again

It sounds complicated just reading your post, Steve, no wonder you found it frustrating! It would be reasonably straightforward to control the MP3 player I demoed in video #40 using a Bluetooth link (from your phone, for example). I really need to find a similar MP3 player that sends back the current tracklist (and the one playing) I think that is a major limitation. Thanks for posting, great to hear from you.

As I am aiming to move the project to a single chip rather than the Nano, i think that the answer is to reuse pins 0 and 1, i can use a bluetooth terminal for debugging if required and then disconnect the bluetooth and plug in the usb when programming, or program via Bluetooth, can't see any reason for that not working as it is just presented as a UART Serial to the computer. ... What can go wrong :-)

Well, either one of two things is happening here: 1. You have a 5v device and all is well. 2. You have a 3v3 device and your device is working but under stress. It may continue to work or fail suddenly. If you can, check the supplier's page whether it is a 5v device (perhaps there is a voltage regulator on board?) just to be sure!

You're most welcome, Asger, glad you liked it! And quite straightforward actually. Thanks for posting.

Hey Golestaan! Welcome! Great you like the videos. I use the FTDI programmer so that the USB is still free to receive Serial data from/to the PC. Otherwise, you are working "blind" as you are using the same pins to communicate with it as when you upload the code, receive Serial messages etc. But, as you've found out, it works with those restrictions. Most developers leave pins 0 and 1 alone for this reason. An FTDI USB to Serial interface doesn't cost a lot and once you have it you can use it to program Sparkfun Micros (and other devices, that don't even have a USB port) for example. Thanks for posting this question, I'm sure others will read it and gain from it too :)

Well, PRObro, I can't do your assignment for you but let's think about this. The GPS module is entirely separate, logically from anything else. If your onboard Arduino is receiving GPS telemetry then it can send that via BT to a receiver (within range, as you say, which might not be that much, 30 metres? How high does your rocket fly?). I think I would have used a longer range data transmission protocol, perhaps using the nRF24L01+ modules, up to 1km range in free space (or sky). Whatever you use, my advice is to separate the two parts of this project and get them working independently before trying to combine them.

@@RalphBacon Thank you. I did what you said and tried them separately first, then combined and it worked. As for the nRF24L01+, this was only a prototype project so I was able to get away with just a proof of concept of sending the data. Thank you for your time, very appreciated.

I'd be surprised if the output from the mouse was not encrypted and proprietary - and the manufacturers are not going to tell you anything about the protocol used, either. I'm not sure how to proceed really. Try the Arduino forum, they probably have more expertise: forum.arduino.cc

If you use an arduino on a very old serial mouse? Or ps2 host chip there some CH chips that could host hid devices mouse and keyboard as ps2 and they an arduino could send aerial to BT what you want..

Most welcome!

Welcome to my channel! If you want the Arduino (via the Bluetooth module) to initiate the connection then you need an HC-05. If you want to connect to the Arduino from your phone (by launching an app) then an HC-06 is enough. That said, an HC-05 offers the best of both worlds inasmuch that it can be either master (initiator) or slave (responder) for just about the same price as an HC-05 (I'm pretty sure it's just a different version of the flashed code contained within it that determines whether it's an HC-05 or an HC-06). So if you have not got a Bluetooth module already get the HC05 for flexibility! I have an HC-05 module and I will do another video in the future with the HC-05 initiating the connection to the phone to 'push' messages out to an Android app. I have a project in mind that I need to complete before winter so stay tuned! BTW did you watch my Coffee Cup Coaster Load Cell video on the HX711 which shows how to connect it all up? That coaster is very popular at work with everybody wanting one! Not that I have the time to build them (I want to make a new one for myself first, for use at home). Thanks for your interest in my channel and I hope I've clarified your query - if not, ask another question!

Watched many of your vids including the coaster one...great stuff. cheers

And I'm sorry you could not download the programs, due to Dropbox withdrawing the shared folder facility grrr, but as you've now highlighted it I will move them to GitHub for other users. On the other hand, I'm delighted you got it working (and, of course, it was all a cunning plan to get you to type it all in, to enhance your experience!). I'll add a note here when I've moved the code so you can compare. And thanks for posting, I'm glad you found it "the clearest explanation yet" (the cheque's in the post) :)

I've moved the code, circuit diagram and everything else to another folder in DropBox (easier than creating a whole Github repository): www.dropbox.com/sh/8tf9fjb2tugkkr8/AAD0jaeRQlWhQtfv764pTEf5a?dl=0 I've updated the links in the video description too. Any difficulties access this, please do let me know!

Hi Ralph Downloaded all the code OK, so thanks for that. I've compared your .ino code with mine and it is virtually identical - apart from a few omitted comments - but I still can't understand why, if I comment out the BTserial.print("ON") or OFF on mine, it doesn't work properly. It will switch on the LED, then get hung up waiting for the two bytes. But yours works OK without it!

So let's see if I understand this: *my code* without the BTSerial.Print statements works fine, but *yours* does not? (Actually, I notice I have two versions of that sketch (have a look in that folder). Guess what the difference is? Doh!) Given that this video was done some time ago you'll forgive me I'm sure if I can't quite recall all the finer details so if the two statements (used, for debugging, I believe, or for sending a response back to your module) is what you need then put them in and enjoy the BT goodness! Once you get the LED working reliably on/off with the reply to your mobile BT device then you will be undoubtedly see the possibilities of controlling *anything* (with a bit of coding). Frankly I'm really glad you got at least one version of the sketch working OK!

Yes, you're right, there are 2 versions, one is called demo which lacks the BTserial.print bit which still works anyway. But mine doesn't. I could understand it (I think!) if it were connected to pins 0 and 1. I wanted to use it as a starting point to transmit data from a DHT11 to a master/slave combination and I've succeeded, having spent most of the day on it. Well, it's a bit wet and windy down here anyway! So thanks again for your help. Oh, and say 'Hi' to Benny for me!

Yes, the way I have it wired most definitely worked just fine! Good resources can be found here for BT modules: www.martyncurrey.com/arduino-with-hc-05-bluetooth-module-at-mode/

It's nice to hear that I helped you! Good luck with your project.

"Do it over the Arduino" needs a bit of clarification! This is an old video and I cannot remember what the FTDI was for. Let me know!

@@RalphBaconwell, I‘m afraid it does not matter anymore as i accidentaly fried my entire project by running to high of a voltage… thanks for the reply anyways , great video!

Good question you have there, Maggie May! Firstly, did you get it working *first* on a standard Uno or Nano? It's always useful to have a working prototype and *then* move to a ported platform. I assume you've used Pin 1 as Rx and Pin2 as Tx for the SoftwareSerial pins? You've successfully established comms from your phone to the BT module (without any µprocessor involved) as per the demo? Are you running the ATTiny85 at 5v or 3.3v? At this point the ATTiny85 just reads serial data in the standard manner, so I am bit confused now. Let me know the answers above and we'll see what else I can think of?

I've found this ATTiny85 specific article on getting BT working, it may help you too: www.instructables.com/id/ATtiny85-Bluetooth/

hi Ralph thank you for your reply . meant to ask but will the apk need to changed aswell?, it does work on a uno. any help would be appreciated in getting this to work.the instructable site just confuses me more because he says connect rx ti pin 1 when pin 1 is reset! regards paul ps as you can tell im a noobie to arduino.

No, the apk is for the mobile phone app, it doesn't have any bearing on the Arduino side of things; it simply does its BT thing (in this case to that BT module). Yes, pin 1 is Reset on the Tiny unless you've disabled that to get another GPIO pin. But if not, ignore that and use two pins that are free. This is always going to be a bit of a challenge because you have so few pins. Now when you say "not working" what exactly happens, if anything? I've assumed you've tested the BT module because you say it works on the Uno. Sure you haven't swapped the Rx / Tx pair over? Final question: why are you so keen to get this working on an ATTiny85?

I am trying to run Rx to pin 7 on the Attiny85 {aka pin 2) and Tx to pin 6. reason for Attiny85 is that i wanted to put it on a board so that i could free my Arduino up for other project but would still be able to return to the boards later. Hope this helps to understand what i am trying to do, maybe im trying to run before i can walk with the programming side.

I'm replacing my original reply to you, George, here goes. Let's do this step-by-step to ensure we are both on the same page: 1. The Android app is up and running on your phone. 2. The Arduino app is connected to the HC-05 via the correct resistor divider and is running 3. You can connect with your phone to the Arduino / BT by pressing the "Choose BT device" button. 4. If you press the ON or OFF on the Android app, nothing happens on the Arduino. Is this as far as you have got or has it failed at step 3?

@@RalphBacon i con't pair the bluetooth device with my laptop when i type in (AT)on my serial monitor i get nothing the red ligth still fiashes fast ?

Hmm, I will have to get one out and see what roadblock you have uncovered, but that may be in a couple of days (over the weekend). Bear with me and do nudge me if you haven't heard back from me by Saturday. From what I recall from this video (it was recorded a couple of years ago now) it was all plain sailing so it's probably some silly little thing we can clear up quickly.

Ralph S Bacon Thanks Ralph!

So, I've had a think. 1. Are you connecting the TX/RX pair the correct way round? That is, the RX of the FTDI is going to the TX of the HC06 module? And ditto for the TX of the FTDI? 2. And you are SURE you have an HC06, not an HC05? The HC06 is permanently in AT mode (when not paired) as soon as you switch it on; mine has a rapid red LED light flashing. 3. You should be able to set the baud rate on your Arduino IDE to 38400 and "Both NL & CR". Then send AT and you should get a response of OK. 4. The HC06 (slave device) will probably have something like JY-MCU on the back (probably).. 5. An HC05 device has something like ZS-040 on the back (probably). Any luck? If not, and you're sure it's an HC06 run the example BT program on your Arduino and try and connect to it anyway using the phone app I supplied. I just tried this again and it connected straightaway (although I had modified my HC06 sometime in the past and called it an RSB which made it easier to identify).

Ralph S Bacon Hello Ralph. Thanks very much for your suggestions. I am definitely connecting the TX and RX correctly. But I will investigate your other suggestions and see whether I get anywhere. Thanks so much for finding the time to reply to me. 😊

@@davidkempton2894 Hi did you get this going in the end because I have the same problem and have tried all of the above....Ta!

You're right about this being some time ago, Dave, but the hardware will not have changed. The main difference between an HC-05 and HC-06 is that the HC-05 can be a master _or_ slave. The HC-06 is a slave only. This means the HC-05 can initiate a connection to another device and the HC-06 can only accept a connection from another device, such as your phone. So you have swapped out a slave-only device with a master-or-slave - which should be OK. Let's do this step-by-step to ensure we are both on the same page: 1. The Android app is up and running on your phone. 2. The Arduino app is connected to the HC-05 via the correct resistor divider and is running 3. You can connect with your phone to the Arduino / BT by pressing the "Choose BT device" button. 4. If you press the ON or OFF on the Android app, nothing happens on the Arduino. 5. Have you put various debugging (Serial.print) statements in the Arduino code to prove that _nothing_ is being received? In the loop() after the BTserial.available statement? 6. You have definitely used the correct pins in the SoftwareSerial setup? 7. The baud rate is correct (I chose 9600 for reliability over speed)? If all the above is a "Yes" then we will have to check the HC-05 vs HC-06 setup. Let me know about the above first. And a big thank you for being such an avid viewer of my videos 🙂

I suspect you have not paired your phone with the device. Go through the pairing process as per the video demo and it will work just fine.

@@RalphBacon Thank you Ralph. I found out the problem. My bluetooth is the hm10 4.0 module. Not hc-05 one. 🤭

Have you tested your FTDI unit, Tor? Does it really give out 3v3? If it does then it didn't cause your BT device to fail, something else has happened (not necessarily bad). Try writing a simple sketch (or take mine) and see if it can wake it up again.

yes. the FTDI gives out 3.3 or 5v. But the BT module itself requires 3.6-6v right? But the RX is limited to 3.3v. That is what I have set up on my breadboard - and the bluetooth (my other one) lights up and connects. The reason I found this video is that I have trouble getting my bluetooth HC-06 devices to hold a connection. It always times out after 10-20 seconds and I don't know why. That happened with both modules I have. Have ordered new ones, but china mail sure takes its time.

DO you mean can you change the BAUD rate, for example, using the Arduino? You _can_ by sending it the AT commands but you will be programming those into a sketch. What if the HC06 device does not respond? Not the best way to do it for the initial setup, at least, Vajra, but,yes, you can send out AT commands just the same.

Theoretically, any USB-to-serial adapter should work. But the pins are different on the CH340G modules. I'd say buy a (cheap, clone $3) FTDI module and go from there.

@@RalphBacon I bought a FTDI and he responded OK only one time, I replaced USB cable (short cable), dupont wires, and no more respond. The communication with serial monitor (ARDUINO IDE) and with serial terminal (Smartphone) it works only with Hello world both side .(but none AT commands)

Ensure you have the BT device in command mode: power off, hold down the small button whilst you power up, keeping the button pressed until the LED flashes slowly (much slower than when you do not keep the button pressed). Then you are in command mode. AT commands should work now. Enter AT and it should reply OK.

For us in the UK that is $4.54 or £2.99, Terry (due to the poor UK -> USA exchange rate for us these days). However, today at AliExpress it drops to just £1.99 plus a few pennies for postage, such is the competition at the AliExpress site. Thanks for the info and also for posting.

Thanks for sharing that, I can't remember what I set mine to, but I'm glad you got yours working, it may well help others reading your comment.

I wish! I should have called my channel Sizzling Bacon!

Yes, just send the required (fixed) number of characters in a struct and it will be fine. This means you can send integers, chars, longs etc without having to worry about it.

I don't have an IOS-based device, Patrick, but I do know they are locked down to the nth degree. So I'm not surprised the app didn't work. But the HC06 device should work if you wrote an Apple-verified app, it's just BT, after all. But then again, we're talking Apple here. Thanks for raising this for others to be aware of.

I didn't program anything for the HC 06 as I did research first. Apple is notorious for locking things down specially in software While the phone is capable of certain things Ios just blocks it mostly for "security reasons" in the end I went for the HM10 which seems to work fine with Ios... I've also been working with CoreBlueTooth which is the apple API and it seems to work fine better then expected.

When you plug it in and type AT you don't get an OK response? Firstly, it can take a couple or more goes to wake it up. More commonly, you haven't got it in Command Mode. Disconnect the device from power, press the small button and reconnect the power whilst you keep the button down. After a few seconds the red light will start blinking slowly. Release the button and try the AT command again, a few times. If still nothing, triple check your wiring.