How to Pair HC-05 Bluetooth Modules

A fast explanation on how to pair two HC-05 bluetooth modules!
!!!!!!!PLEASE READ IF YOU ARE HAVING TROUBLE PAIRING YOUR BOARDS !!!!!!!
COMMON ISSUES:
Issue 1: This method works ONLY with an Arduino UNO. (edit: One user claims it works with an Arduino Mega as well but I have not tested myself. Could be an option if you have a Mega). Once the boards are paired you can use whatever you want, but for programming in AT Command mode you MUST use an UNO.
Issue 2: Some boards require the button to only be held during power up (as seen in video). Some boards require the button to pressed at power up AND when hitting "enter" on AT commands. Some boards require the button to be held at ALL TIMES in AT mode.
Issue 3: ERROR: (7) when trying to use the AT+BIND command. Your address be entered in this exact format XXXX,XX,XXXXXX 4 characters (comma) 2 characters (comma) 6 characters. If the address given by the slave module is not in this format, you must add zeros at the beginning of the section to make up for it. i.e. If the address given by your slave is 13:EF:C76A you would enter that as 0013,EF,00C76A. If the number of characters is correct an you're still getting the error; check that you do not accidentally have a space at the end of your string (very common).
Issue 4: The Baud Rate for AT Command Mode is 38400. The default Baud Rate for communication between modules is 9600. This can be changed with the command AT + BAUD
If you are still having trouble, post in the comments. I also offer pre-paired boards from my store: www.patrickstefanski.com/store
NO-INTRO TUTORIALS - Don't you hate when the first 10 minutes of video is the creator talking about what he's going to be doing and why he is going to do it? GET TO THE POINT! No-Intro Tutorials are designed to cut to the chase and dive right in.

[@PatchBOTS]

If this process isn't working for you, please read the video description. I've updated it with a few of the most common problems. If that doesn't help, search through the comments, i try to respond to every question. If that doesn't work, post your new issue in the comments and I will get to it. If that doesn't work, I sell pre-paired boards in my store. Link in the description!

[@maulanafahman9332]

bray ngubah ke 38400 baud ratenya gimana

[@JonahStubbs]

Did you do this for your clone comm pad?

[@JonahStubbs]

And could you make a video all about your clone comm pad because I want to do what you did but I’m not sure how you did it and would like an explanation and how-to.

[@ArcaneStellaris]

It worked for me with an arduino mega for AT Command mode stuff

[@PatchBOTS]

@@ArcaneStellaris that's great to know, I'll add it to the description

[@reinerhildebrand5915]

Excellent tutorial! Clear explanations, no intro, no background music, no bla-bla, just pure information. Greetings from Berlin!

[@MakerProjectLab]

Great explanation. Clear and concise. Well done. Subscribed.

[@PatchBOTS]

Maker Project Lab perfect!

[@PatchBOTS]

After checking out your channel I sub'd right away. Really looking forward to going through your video roll. Great stuff!

[@adkeco]

You gave me all I needed to know... in 5 minutes. Outstandingly clear and concise. Cheers!

[@vedansh29]

tHE MOST EASY VIDEO FOR THE THING I SEARCHED FOR

[@PatchBOTS]

Thanks!

[@Osmanity]

TOOK ME 1 YEARS TO PAIR THIS HC-06 AND U MY FRIEND MADE MY DREAM COME TRUE AFTER 100 VIDS WITH POORLY EXPLATION BUT U SAVED ME FROM GIVING UP MY DREAM AND FOR THAT I WANT TO SAY THANK U FROM THE BOTTOM OF MY HEART

[@Poult100]

Good tutorial re pace, no padding, no 5h1tty music and once the bid description is read, all is well. One other small comment; the paired flash is not synchronous. They both flash together to begin with but normally gradually drift in timing. Not important but some may worry.

[@1e0_oki]

Thank you so much I have been trying to pair the the modules together the whole day, NOBODY mentioned that you have to remove the high signal on the EN pin and swap the TX|RX BUT YOU. you are amazing .

[@PatchBOTS]

Glad it was helpful!

[@mewintle]

Super clear and concise. I wish all instructional videos were this good! Thank you!

[@PatchBOTS]

Really nice feedback thanks!

[@Hurtcules]

The best tutorial I've seen so far on this subject. Gonna give it a try in a day or so.

[@PatchBOTS]

Hurtcules thanks! that means a lot! good luck and message me if you run into any trouble

[@LewisO.]

OMG OMG OMG OMG OMG YOUR EXPLANATION IS THE MOST SIMPLEST ONE TO FOLLOW AND YOU TALK FAST AND IS WELL SPOKEN MAKES IT EASY TO FOLLOW AND I WANNA BE LIKE YOU WHEN YOU GROW UP SUBSCRIBEDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD

[@ljay0778]

Great video, and i have no idea how it ever worked with TX going to TX and RX going RX in the first place. Most the world knows they need to be reversed as the module TRANSMITS into the RECEIVE pin . but it general it worked for me doing it the right way . thank you.

[@doctorteeth]

Puzzled me at first - but I think the cross is unnecessary because the data is just passing through the serial interface from the USB port, rather than originating within the Arduino.

[@andrewmagdaleno5417]

This video really helped out a lot thank you for the clarity and speed!

[@tchiltchil]

Great video and explanations.Thanks from Nairobi

[@nomaanishfaq8917]

THE BEST EXPLAINED VIDEO I'VE EVER WATCHED.......... THANK YOU VERY MUCH :)

[@nancyrobles8481]

THE SHORTEST VIDEO I FIND, AND THE GREATEST, YOU EXPLAIN VERY WELL, YOU SOLVED MY PROBLEM, THANK YOU VERY MUCH FRIEND, NEW SUBSCRIBER

[@PatchBOTS]

Great! Glad to help!

[@BHANUPRAKASH-nc8hz]

It worked , with easy with your clear cut explanation , thank you very much sir.

[@46449771]

Very good video. Straight to the point and perfect instructions. Thanks.

[@ELECTRICALTOOLBOXPH]

Thank you so much! Brief and concise..

[@antoniosantos6104]

Thank you so much for this video, I was looking for a video that explained it easily and thoroughly!

[@mikex691]

Excellent, excellent!!! You inspire me. Please do more like this !!

[@webslinger2011]

Need to add zeros for binding the address if not complete. Also, I've used Invootech method to connect the modules.

[@MichaelPick]

Great video! Subscribed!

[@PatchBOTS]

Thanks man!

[@Tokke_ALT]

Its a very good and clear video. Can u make another video that you program a simple ting with it like a press on a button sends signal to the slave and lights up a light. Can u also make another video where u can send with both that u can use them like a chat, or is it not possible.

[@devindavis1833]

This would a fantastic addition

[@hasanadmani6388]

amazing tutorial finally got everything to work great job!!!!!!!!!!!!!!!!!!!!

[@Alex-nl4ib]

You literally saved my life, THANK YOU A LOT

[@PatchBOTS]

Glad I could help

[@ouchanihida3327]

@@PatchBOTS You advise me what type of GBS modules that will be compatible with a Bluetooth module and at the same time an SD card . You can advise me because I'm a little lost thank you

[@glindquist5635]

Thank you so much, saved me a lot of frustration!

[@kingsleyjide4486]

New subscriber here! this video was concise and full of value.. I have a question, is it possible to add more than one address for the master to connect to whenever any of the added addresses are in range?

[@PatchBOTS]

Not that I'm aware of, but check more recent firmware guides.

[@IanZ_Forge]

Thanks mate! This helped a ton! God bless

[@DanGahagan]

I was trying to do this with a Arduino Nano and was not successful. Bought a Arduino Uno and it took 2 minutes =) Thanks!

[@PatchBOTS]

Great glad you found the solution!

[@venkatmourya5117]

SUPERB EXPLANATION

[@yuchoy1]

Very nice and clear! Thanks for the info!

[@wiseThingz]

as I tested, to get into AT command mode, you only need to hold down the button while switching on HC-05. immaterial if u have made EN/KEY pin HIGH

[@jeffl7124]

Best video on this subject I've seen so far! Great job! I'm assuming you're using a 3.3V arduino (since you're not running the arduino's TX pin through a logic level converter or resistor voltage divider)? You might want to specify this in the video. I'm pretty sure that the HC-05 can only handle 3.3V on its TX and RX pins and that 5V would fry it. Or maybe I've heard wrong and the HC-05 can handle 5V just fine?

[@PatchBOTS]

Nah I think they can handle it. Haven't had any problems yet.

[@jeffl7124]

Just fried my HC-05 board by connecting my arduino's TX pin to the HC-05's RX pin (without first going through a logic level converter). So it's definitely possible to fry it (as I feared). Not sure how you're getting away with 5V.

[@PatchBOTS]

Yeah man, doing some research it says you should use a voltage divider on the RX pin to get it down to 3.3v. But I have 2 sets of HC-05's in my BB-8 driod, and I use one set for testing things all the time and have never had a issue with frying them. Really strange.

[@jeffl7124]

No worries. It was cheap. The back or your modules look a bit different than mine. It seems that not all HC-05s are created equal. There's probably varying base boards and manufacturers out there. Anyway, it would be awesome if you added a quick note about this in your video so no one else has to go through this.

[@PatchBOTS]

Yeah, maybe a brand issue. I'll put a notation in there later today and make a section in the description of the video.

[@gpTeacher]

Thanks very much for very clear instructions!

[@PatchBOTS]

You're very welcome! Glad it worked for you!

[@arivnidunami3047]

what i looking for, thanks. good video.

[@eleftheriostriantafyllidis3012]

Hello! Great Video! Right to the point. One question, do we have to set the AT commands every time we disconnect and re-connect the arduinos ? Or do the HC-05 "remember" their master or slave state ? Thanks!

[@PatchBOTS]

They remember!

[@eleftheriostriantafyllidis3012]

@@PatchBOTS Insanely fast reply, thank you, really appreciate it :)

[@PatchBOTS]

@@eleftheriostriantafyllidis3012 No sweat, if you run into any issues post them here and I'm happy to help

[@eleftheriostriantafyllidis3012]

@@PatchBOTS Oh, you could add in the description that Error (7) may also come up in case the address is two characters less; For example an address FCA8:9A:22ED is two characters less than in your tutorial in the end. This is simply fixed by adding zeros in the end, i.e.: FCA8:9A:22ED00 :)

[@davidhead6549]

Cannot get HC-05 to accept AT commands. Have followed instructions to the letter on two different modules, with two different Unos, and two different sets of jumper wires. Have tried all of the

[@PatchBOTS]

Sorry not sure what could be wrong there.

[@vkb1]

Make sure you use this format for your AT+BIND=xxxx,xx,xxxxxx. Add zeros to pad the address. I was getting Error(7) (Bluetooth address: LAP is too long.). But this fixed it.

[@PatchBOTS]

Good advice, this error can also be caused by accidentally leaving a space at the end of your numbers, which is very easy if you're using Notepad on Windows. This error is extremely common among those that message me.

[@davidhead6549]

By the way, an excellent video.

[@rogerdeutsch5883]

Great video. Subscribed.

[@PatchBOTS]

Thanks Roger, that's the best kind of feedback there is!

[@jozzetrick]

Hi, I have a HC-5 and when I try to repower it using my power supply it worked but 5 second after it didn't work anymore the light is not blinking, and the resistor is very hot it even melts the plastic cover in it. Do you know how to fix this problem?

[@ilikekids8095]

It fried up.go buy another one pal

[@marsanishadraa]

Great video thank you!! I follow your instruction to write AT in serial monitor and the reply is OK so when I write AT+ROLE=1 there's no response in the serial monitor, what should I do?

[@almeespinosawild2196]

you found any solution?

[@marsanishadraa]

@@almeespinosawild2196 actually I already finish that 2 years ago😅

[@govorilegko]

The best explanation ever on how configure and pair 2 HC-05 modules. Very clear. But I cannot even turn on the light (pin 13) on Slave from Master. I don't understand what I do wrong way. Can you make some simple code and really pair 2 modules?

[@PatchBOTS]

What exactly are you trying to do? What input are you trying to use on the master side to turn the light on on the slave side?

[@govorilegko]

everything is okay, thank you

[@enestastan7147]

I have a question. What about the passwords that we configured? I applied exactly the same procedure but master could not connect to slave just because I have changed 1234 default password to something else. When I reconfigured the slave's password to be 1234 master could connect to it? If pasword matters (which seems so) how can we let the master know or bypass the password of the slave?

[@kbruin79]

Great tutorial. This might be Ok for connecting couple pieces what if you have a 100 or 1000 Bluetooth pairs is there a way for two known Bluetooth hardware devices to auto connect?

[@ppionke]

SHOT AND SHOW ANY STEP NEEDED gj !!

[@Greebstreebling]

Mmmm, what about the 3.3V logic level requirement? The HC05 Rx pin might survive for the duration of testing, but longer term you'll kill your HC05. It needs a logic level shifter for long term use, as per datasheet.

[@PatchBOTS]

Yeah you're totally right. A voltage divider is needed for long term use.

[@richard1001001]

Great video. Would you mind if I asked a question? I want to remotely control some 12v lights, but need to use a standard toggle switch. How would you connect a switch to one of these units. I am a new boy to these products so my knowledge is limited. Thank you.

[@PatchBOTS]

Well it would be connected to a microcontroller on both ends so connect the switch to that and transmit the on/off data

[@dgrek9459]

Yeah its very similar to wireless controlling of an LED just you will need to wire your micro controller to your 12V power supply and lighting to give it the input from the switch which is also wired to a separate micro controller

[@emyalfaro]

Thanks a lot for this! New subscriber =)

[@PatchBOTS]

Much appreciated! Thanks for watching, glad it worked out for you

[@emyalfaro]

I got everything working just in 5 minutes! Thanks again!

[@dashl5069]

it is not working with my nano, it has had other problems like not using the normal USB drivers (SDTI are the most common I believe) however I cannot see why this would not work, any ideas? Thanks

[@PatchBOTS]

@swishy _ fishy In the end you can use a Nano for your project, but it appears you need to use an Uno to do the AT mode commands. Others have had the same issue using a nano which was resolved by switching to the Uno.

[@ziyujin9106]

Great video thank you!! I follow your instruction to write AT in serial monitor but there is a problem in writing AT+BIND. Can I know why?

[@talitaanogueira]

Thank you! You saved me!

[@andrecartagena3201]

Nice, your also very smart

[@rohitchaturvedi2271]

Hc 05 logic pins are 3.3 v, UNO is 5 v, can it tolerate ?. I saw in a Great Scott video to use a voltage divider between tx of uno and rx of hc 05.

[@PatchBOTS]

Yes, should be fine without for programming but you should probably use one for regular use

[@nenorse]

For the Arduino Nano - I needed to drop the voltage to 3.3v on the RX Pin by connecting a 1k and 2k resistor. (search google for connecting HC-05 to Arduino Nano)

[@Rotellini-9809]

hey hope you see this comment, i followed the procedure with an arduino uno everything is ok the module respond ok to every command i send but when i try to change the role to 1 it just stays 0, even if i get an ok after the command AT+ROLE=1

[@hairiyaacob6289]

great explaination. just a quick question: do we really need to make a potential divider for the TX connection from arduino using 1k and 2k resistors. is it really necessary?

[@PatchBOTS]

hairi yaacob you probably should yes. For just pairing them I haven't had any issues, but for long term use it's definitely on your best interest

[@MicroModDude]

I’m new to this? You didn’t explain how to wire the boards.

[@lania4334]

Isn't it bad to take the pin directly to the Arduino without using resistor does it not damage the Bluetooth.

[@akramhassan7484]

Really great explained but I've got a question I want to send send and receive data in my sonar project( servo+ ultrasonic), Can it be done with the method you explained with these Bluetooth modules ?? Thanks

[@PatchBOTS]

Hi Akram, This tutorial just shows how to set up communication between the two modules. So this tutorial would get you started. Yes, you can absolutely use these two bluetooth modules in your sonar project. You'd can send the data from your sensor to your servo over bluetooth or your remote to your servo, whatever you need. The bluetooth is just replacing i2c or other serial connections with a wireless solution. HOWEVER, you'd need to seek out another tutorial for that, this one is just about establishing the connection between the modules.

[@amihemat5130]

thanks, now a question : how we can have directly connecting with HC-05 and headset bluetooth?

[@isabelpestana1081]

Great video!! One question tho, can I use a arduino nano after?

[@PatchBOTS]

Yes. UNO is only needed for programming. Then you can use anything you'd like.

[@isabelpestana1081]

@@PatchBOTS thank you so much!!

[@davidhead6549]

Cannot get HC-05 to accept AT commands. Have followed instructions to the letter on two different modules, with two different Unos, and two different sets of jumper wires. Have tried all of the fixes in the description. Odd thing is the modules appear to be in programming mode with or without pushing the button at power up.

[@PatchBOTS]

I know you said you did everything to the letter, just double check these two things: 1. Your baudrate is set to 38400 in the Serial Monitor. 2. TX-->TX RX-->RX

[@galacticxranger9863]

i want my bluetooth hc 05 to connect to any device so if I use ur tutorial then I can connect my phone to the slave module and then I can use it . am I correct?

[@byungshin8773]

Hi I do not know if you are still answering questions, but I am able to follow your steps to a tee except when I switch to the other bluetooth module. When I do, I am unable to get a response from the serial monitor. No matter how many times I type "AT", nothing seems to come out. Is this a problem with my own bluetooth module, or is there something I missed in the video?

[@PatchBOTS]

Troubleshooting: 1. Are you using an Arduino UNO? You must use an UNO to program. 2. Is the light doing the slow, long blinks representing AT COmmand Mode? 3. Is there a blank sketch uploaded to the arduino? 4. Is your serial monitor set to 38400 baud? If the answer to all these questions is yes then you may have a busted module, try another module with the same method to confirm.

[@machwasmakerspace362]

WOW... that's a how to the way I like it!

[@robGamings08]

Hey so I followed your video, (great job by the way!), and they are blinking twice every 2 seconds like they are paired, but it’s back and forth and not synchronized. Is it still paired? I couldn’t find anything wrong with what I did.

[@morrism6743]

Sir, after all the steps is done, what if the blinking light is not synchronized? But both blinking lights actually get slower but not synchronized

[@salvo5631]

My problem is at AT Command mode. I bring up my Serial monitor up on 38400 baud . I type in AT in the bar and get nothing not even a error what happened what have I done wrong. Also does it make any difference if i am using a Iphone as i can not see it in my Bluetooth.

[@ranidusoysa8789]

In my case it is not bind. when I bind serial monitor shows 'OK' but still not bind. can you tell me why is that? --Very urgent--

[@bufferingmp.018]

Hello pathbots, this was very helpful and I almost finished in less than 10 minutes but I ran into a problem. It says that my modules are binded and stay binded but they won't connect. I'm using an Arduino uno and have checked every step and everything is correct. Not sure why?

[@luiscostoya7879]

I know others have probably asked but I cant seem to get a response at all from the AT command. I get the show blinking to happen but when I type AT on to command line I get nothing in return. Im on an Arduino Uno, made sure to set baud to 38400, and TX -> TX + RX -> RX. Not sure what could be wrong, any help would be appreciated.

[@steve_lion8563]

I have the same exact issue

[@TheOnlyLama]

Thank you so much

[@ashinthaCARBON]

huy, I did the same thing as "AT+ROLE=1" it says ok, but when I try to verify it's still in the slave mode. Can you tell me how to fix it

[@amizu1006]

I succeeded in making the HC-05 blink slowly, but there was no response when I opened the serial monitor and entered AT twice (I entered the command within a second). serial monitor set to 38400 baud, I used an Uno R3

[@UserBatoste36]

Hello, when I make an AT+ROLE=1, I get nothing and the role keeps being slave (0). Any idea why ?

[@almeespinosawild2196]

Hello did you find any solutions? Im at the same page

[@UserBatoste36]

@@almeespinosawild2196 no unfortunately my module was a fake one and there was nothing I can do to make this command works. Maybe by trying to flash a new firmware, but it's out of my knowledge

[@iggyboyTV]

it is possible that thus setup is control by mobile phone?

[@xavierr4508]

Connecting the module's serial lines to 5V might fry it!

[@baitodansu]

Hey! My Module Is Won't Turn On... Is Not Blinking... Please helpme....

[@Dheazzo]

Can I use these modules to transmit audio between two devices

[@markgreco1962]

Thank you very much So do they also send the command using the wire library on Arduino Is there anything we have to do in addition in the code?

[@PatchBOTS]

The way I've used them is with UART communication. I'm not sure if you can use it as an I2C device with the wire library but it's something to look into.

[@Seifsstudying-wq2nv]

What a legend

[@doctorteeth]

Having tried to get into command mode with a Nano and failed several times, I saw this video - and of course it works with a Uno - but I'm not sure why!

[@lustrals1273]

I don't have a reset button on my Bluetooth module, please help

[@nicknavarrete2838]

Hey, Ive been working with them using a different micro, UART is working, Role and CMODE are working. For whatever reason, the address I try to bind is not remembered by the HC-05. Any ideas?

[@rubenamoretti1219]

Can you explain about the AT+INIT and AT+INQ commands? I want to use the RSSI property, maybe that can help

[@wanghuwanghu]

Both BT modules need to have set the SAME PAIRING CODE. :) Hope that helps.

[@thibaultdenoix1763]

It didn't just help, it saved me ! Thanks a lot

[@munch15a]

So ive gotten it too AT command mode as indicated by the flashing light but thats as far as it goes the serial monitor will not give me any feed back ?

[@dashl5069]

I have this problem too with my nano, what board are you using?

[@josephnavinkumar3089]

im using a uno board but it still dosnt work

[@dgrek9459]

@@josephnavinkumar3089 some hc-05 boards have issues in the 38400 baud rate. There are codes I have found online to allow you to try this same tutorial in the 9600 baud rate. Try looking for these

[@minugupta9532]

Sir my hc05 is blinking twoceand turning off Can you help me?

[@Graham1904]

Don't you need level changer on the tx/rx lines as these are 3V3?

[@scitechnotuber548]

Is there any way in which we can define the address of master in the code of slave circuit ?? To connect it directly

[@VidAdiction]

I can not get the HC-05 to enter paired mode. I feel like I am following this guide exactly. PLEASE HELP!!!

[@Nate-hv2ub]

Look at the description

[@PatchBOTS]

Sorry this comment got flagged by youtube, I just saw it for the first time. Are you still having trouble? Please post a more specific problem you are having and I'll be happy to guide you.

[@VidAdiction]

@@PatchBOTS I actually got them to pair! I found another circuit that used a level converter, and it worked great! Thank you!

[@PatchBOTS]

@@VidAdiction Awesome!

[@shrijanmaram7939]

Can I do the same if I want to connect to smartphones rather than another HC-05?

[@EVERYTHING-tw5vm]

thanks alot

[@unglaubichuberlieber8048]

thanks for the clear, step by step explanation, one question: how can one master be connected to two slaves concurrently??? thanks for your reply

[@PatchBOTS]

If this is possible I am unaware of how to do it.

[@kumarjha1729]

Nice video. I made Master and Slave, but I didn't get last step when you used other arduino and exchanged RX-TX and TX-RX (bluetooth and Arduino uno)?

[@PatchBOTS]

Oh okay let me explain a little better. Tx is your "transmitter" and Rx is your "receiver". When you're programming the modules through AT you want the transmitters connected to each other and the receivers connected to each other. After everything is programmed and you have your master and slave, you need to switch around one pair of those wires such that the Transmitter of your Arduino is connected to the Receiver of your Bluetooth Module and vice versa. This way one receives what the other transmits.

[@kumarjha1729]

@@PatchBOTSthanks for 1st doubt. Also if I want to send 5 sensors data by bluetooth, in that case which of the following two methods will be better. 1. Using 2 arduino uno and 2 HC05 MODULE...One arduino uno connected to Laptop for monitoring in Serial monitor. 2. ONE ARDUINO uno and one HC05 MODULE directly interface with laptop bluetooth. Also can we interface the master module with MATLAB? Kindly share your experiences. Thanks

[@ouchanihida3327]

You advise me what type of GBS modules that will be compatible with a Bluetooth module and at the same time an SD card . You can advise me because I'm a little lost thank you

[@korasukaro7794]

thanks for the video .. subscribed

[@PatchBOTS]

Glad it worked for you! Thanks for the sub, good luck with your project!

[@hsiehpanggi]

Hello, teacher, can you directly write code in arduino ide to import AT commands into HC05? In addition, one master can be paired with multiple slaves, and the master will control all slaves synchronously?