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

[@davehiginbotham5992]

Thank you Ralph, The answer to your reply query is definitely YES. I've done all 7 more than once. BTW: I got started looking at Bluetooth when I purchased two Nanos that have integrated BLE. When I couldn't get those talking, I thought I might learn something that might help by replicating your #36 & 37 experiments. Maybe you could do another episode focused on BLE (or just Bluetooth Ver 4). I did learn that there are different sets of AT commands. Meanwhile I'll keep trying to get the HC05 going by trying different Modes, etc.

[@RalphBacon]

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.

[@douglasthomson2986]

Great explanation of this Ralph. Thanks for making the video. Definetely need to try this out soon.

[@RalphBacon]

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.

[@douglasthomson2986]

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.

[@markgreco1962]

I was trying to learn about AT commands and here you are.

[@RalphBacon]

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

[@markgreco1962]

Ralph S Bacon absolutely

[@caribbeanchild]

One of my HC-06's (GW040) has nothing on the back about Level 3.3v and works just fine without any voltage divider. Using 5 volts all around and no problems! Lots of people on KZbin also have no problems!

[@RalphBacon]

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!

[@qzorn4440]

a wonderful walk through, now for the esp32 version. 😍 time for tea Mrs. Peel.

[@RalphBacon]

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!

[@qzorn4440]

@@RalphBacon thank you BT is new to me.

[@domseschummsi5476]

Hello Ralph, I am faced with the Problem of beeing out of time to buy an FTDI whitch means ill have to do it over the arduino directly. I however do not know how one would do that and would greatly appreciate your help!

[@RalphBacon]

"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!

[@domseschummsi5476]

@@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!

[@emj6724]

Thanks Ralph Great video very cool very informative :)

[@RalphBacon]

Glad you liked it!

[@emj6724]

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

[@philbowen8658]

Hi Ralph, Had a quite afternoon and found your channel, just got through all 36 videos. THANKS found lots of ideas and tips. I was wondering what terminal you are using in this video? it's not the standard Arduino IDE.

[@RalphBacon]

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.

[@stevef4943]

Like the videos! .. I have been looking at integrating bluetooth with other serial devices on the Nano, may be worth putting on your list an additional video on the vaguaries of using, for example, a Bluetooth Module to trigger a Serial Controller MP3 Player (or any other serial device!) by setting up multiple soft serial ports, or reusing the normal tx/rx pins used by the direct USB.. fun but frustrating !

[@RalphBacon]

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.

[@stevef4943]

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 :-)

[@mohamedsadokjomaa5579]

why i type in the serial monitor and hit enter there's no response how can i fix that

[@RalphBacon]

Ensure your TX/RX pins are connected correctly (TX to RX and vice versa).

[@noweare1]

Hello Ralph, just wondering why direction is from Arduino Pin 6 to HC06 Rx and Tx goes into Pin4. To me it looks like Rx should be Tx and visa versa. I know I am years behind but I just bought a couple of HC05 modules and trying them out. Hope all is going well. EDIT: Nvr mind Ralph, saw another vid and had it wired same as you so will have to get direction figured out that make sense to me.

[@RalphBacon]

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/

[@josephfranco9182]

I try with a CH340G instead of FTD1 and it does not OK response. Should it work still.

[@RalphBacon]

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.

[@josephfranco9182]

@@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)

[@RalphBacon]

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.

[@petewhite4233]

Hi Ralph Just been using these two programs of yours. I was unable to download them as they are apparently no longer available, so I was labouriously copying them off the screen, but was unable to get it to work properly. I then discovered that I needed to add "BTserial.print("ON") /("OFF") which was missing from the screen version. It then worked like a charm. Thanks, though, for the clearest explanation yet!

[@RalphBacon]

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) :)

[@RalphBacon]

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!

[@petewhite4233]

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!

[@RalphBacon]

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!

[@petewhite4233]

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!

[@munthiraljohani1998]

really really thank you I almost quit my project

[@RalphBacon]

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

[@chrisarmstrong8198]

Brilliant video !!

[@RalphBacon]

Glad you liked it!

[@TorIvanBoine]

My unit seems to have died when using the FTDI at 3.3v. at least the bluetooth's LED isn't blinking anymore

[@RalphBacon]

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.

[@TorIvanBoine]

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.

[@wowcoolm860]

Ralph, I am designing a weighing system that connects a load cell to an HX711 to an Arduino and then bluetooths the result (either the raw data or the value converted to a weight) to an Android smartphone. I then also want to be able to tare and recalibrate the scale from the smartphone. Which bluetooth module do I need for 2-way communication? HC06 or HC05? Confused!

[@RalphBacon]

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!

[@wowcoolm860]

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

[@georgepederson5015]

I get nothing I've tried a few options can you help or give suggestions I'll turn around RX and TX and I have tried different programmers models

[@RalphBacon]

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?

[@georgepederson5015]

@@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 ?

[@PR0bro]

Hi, amazing video extremely well taught. Learned more in this one video than watching several others. I am under a bit of stress though, I'm in grade 10 and my tech project is due in two days. I chose to make a rocket that would send its coordinates to a device within Bluetooth range. I purchased the ublocks Neo-6m GPS module and the HC-06 Bluetooth. Would I be able to initiate a connection from the device and receive the GPS data in the Bluetooth Terminal? I am brand new to Arduino and after lots of trying I am running out of time, I'm wondering if you can help.

[@RalphBacon]

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.

[@PR0bro]

@@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.

[@_tinkerBOY]

Hi Ralph, thanks for this nice tutorial on bluetooth! Is it possible to use this module to read inputs from a Bluetooth mouse?

[@RalphBacon]

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

[@kitecattestecke2303]

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..

[@shyamnandankumar9955]

Nice ! Plz keep it up.

[@RalphBacon]

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!

[@NaderTheExpert]

Hi Ralph,Thanks for great educational Videos, well explained! One question though, Why do you need FTDI232? I used Arduino Uno Rx (0), TX (1) and Arduino sketch to send AT commands and eliminated the need to purchase FTDI232.

[@RalphBacon]

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 :)

[@jmc_fpv]

Hi, please. Muito led is flashing with a 1 second delay. And when I tried to send AT via serial become a message: ERROR on serial screen :(

[@RalphBacon]

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.

[@jmc_fpv]

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

[@davehiginbotham5992]

Hello Ralph, I've watched all 147 of your videos (and those regarding Arduinos multiple times.) And I've successfully replicated and modified many of your projects. However, when I try to duplicate the #36 Bluetooth LED experiment (using a slave DSD TECH HC-05 in place of the 06 you show) I can't make it work. Changing the HC-05 by using AT commands through FTDI all works as you show. But, for controlling the LED using a MEGA, I've tried both sketches and also tried adding the "BTserial.println" changes someone suggested. The Android App connects with the HC-05 OK(?) and reads back the "Set up complete" message. But nothing seems to be transmitting from the App by the Arduino and so the LED remains stubbornly OFF. I'm sure I've faithfully replicated your wiring and have tried changing '05 modules, etc. I realize it's been a long time since #36 was done and the '05 architecture might have changed enough to be the problem - but my research hasn't found anything useful in that area. Any ideas or suggestions about what I might be doing wrong or should change in the setup?

[@RalphBacon]

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 🙂

[@davidkempton2894]

Hello Ralph. I really like your videos and the way you explain stuff. HOwever I have had not much success with talking to my HC06 module using my FTDI module. I get no response. I even got the supplier to send me another one but same result. Any suggestions as to what I might be doing wrong? Yes I have got it set to 3V3. Pairing light is flashing and I have done a TX/RX loop back test on my FTDI module and it works fine then. Cheers.

[@RalphBacon]

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.

[@davidkempton2894]

Ralph S Bacon Thanks Ralph!

[@RalphBacon]

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).

[@davidkempton2894]

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. 😊

[@andymouse]

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

[@AtlantaTerry]

The HC-06 module used in the video may be found here for US $4.09 including shipping: www.banggood.com/HC-06-Wireless-Bluetooth-Transceiver-RF-Main-Module-Serial-For-Arduino-p-80364.html?rmmds=detail-bottom-alsobought__5&cur_warehouse=CN

[@RalphBacon]

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.

[@maggiemay8696]

Hi Ralph, loved this video but could you tell me why it does not work on Attiny85 with the pin numbers changed

[@RalphBacon]

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?

[@RalphBacon]

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

[@maggiemay8696]

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.

[@RalphBacon]

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?

[@maggiemay8696]

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.

[@sevenminuteswiththelord]

Is it possible to read more than one character?

[@RalphBacon]

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.

[@mendebil]

your last name is a subscriber magnet I bet

[@RalphBacon]

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

[@YusraozzA]

Thanks alot

[@RalphBacon]

Most welcome!

[@9b_vajra4]

Awesome vid , but can we communicate with hc 06 with just the arduino

[@RalphBacon]

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.

[@patricksmit1090]

Nice video just one comment... The modules discussed do NOT work with IOS/iPhone... Just to let others now up front as my project will be IOS based... For the rest very clearly explained...

[@RalphBacon]

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.

[@patricksmit1090]

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.

[@avejst]

Thanks for sharing :-)

[@RalphBacon]

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

[@ronchampagne8484]

Ok . SO what are the people who can't establish communication with the HC06 supposed to do ? I can talk to FTDI but not the HC06 It's this problem which leads many of us here in the first place !!

[@RalphBacon]

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.