Cannot get my ZS040 into AT mode

Hello everyone, I am currently trying to use a ZS040 bluetooth module and setting it up to slave by entering AT mode, however it does not work even when pressing the button or feeding 3V3 directly to pin 34. It keeps blinking every one second and I don't know what else to do.
Any ideas or suggestions?

The standard rate for the LED is about 2Hz in communications mode. In AT mode it is slower, and you could be there already.

Nick_Pyner:
The standard rate for the LED is about 2Hz in communications mode. In AT mode it is slower, and you could be there already.

The blinking rate does not change at all after I try going into AT mode. It keeps blinking every one second or so

It is probably faster than you think but the lack of change indicates it is not in AT mode. I might point out that Bluetooth is in slave mode by default, and you will be amazed how many people can go through life without ever having to use AT mode. In the, as yet unlikely, event that you need to use AT mode, you can get good advice on the Martyn Currey website, and ou might also find the following background notes useful.

http://homepages.ihug.com.au/~npyner/Arduino/GUIDE_2BT.pdf
http://homepages.ihug.com.au/~npyner/Arduino/BT_2_WAY.ino

Nick_Pyner:
It is probably faster than you think but the lack of change indicates it is not in AT mode. I might point out that Bluetooth is in slave mode by default, and you will be amazed how many people can go through life without ever having to use AT mode. In the, as yet unlikely, event that you need to use AT mode, you can get good advice on the Martyn Currey website, and ou might also find the following background notes useful.

http://homepages.ihug.com.au/~npyner/Arduino/GUIDE_2BT.pdf
http://homepages.ihug.com.au/~npyner/Arduino/BT_2_WAY.ino

The problem that is happening now is that I'm trying to bind a Master HC05 to a slave one and it keeps showing up error(0). The format of the address of one is way different that the other one, is that a reason as to why it is not working? I am pretty sure one of the modules i have is HC05 but the others ones im not so sure. I'm guessing one of them is 4.0 because I tried the AT+VERSION and it showed something as in 4.0

Well, I guess a proper indication of intention, and a fair knowledge of what you are holding in your hand, is more to the point than trying to make a slave a slave. Of the three bluetooth modules that may be on a ZS-040 backboard

HC-06 identifies as LINVOR, has two chips, usually four pins and no button

HC-05 usually identifies as HC-05, has two chips, must have six pins, always has a button.

HM-10 has one chip and will not work with either of the above.

All have some commands that are common and some commands that are exclusive, so making sure you know which is which is a really good idea. One thing that they all have in common is that they must be wired to Arduino Rx>Tx and Tx>Rx, which could be one of your problems, but not likely to be the only problem.

Nick_Pyner:
Well, I guess a proper indication of intention, and a fair knowledge of what you are holding in your hand, is more to the point than trying to make a slave a slave. Of the three bluetooth modules that may be on a ZS-040 backboard

HC-06 identifies as LINVOR, has two chips, usually four pins and no button

HC-05 usually identifies as HC-05, has two chips, must have six pins, always has a button.

HM-10 has one chip and will not work with either of the above.

All have some commands that are common and some commands that are exclusive, so making sure you know which is which is a really good idea. One thing that they all have in common is that they must be wired to Arduino Rx>Tx and Tx>Rx, which could be one of your problems, but not likely to be the only problem.

Ok your answer was pretty helpful. I did not know about the existence of the HM-10 bluetooth module and after looking it up it is the one I have and I'm trying to use to set as a slave. The other one is a HC-05 and works wonders, just like you described. The third BT module I have I still can't seem to understand what model it is nor why it doesn't go to AT mode. It also does not have a button.
Thank you!

Could you provide me further help by PMing me? I'm developing my final project and I haven't worked with bluetooth modules that much.

Best regards

I think PM is a bad idea because it excludes others. You need to know what the third bluetooth is. This cannot be hard. You should be able to power it up, sniff it with the phone, and then it should tell you. See my previous. There is a fair chance it is an Hm-10 (one chip) or an HC-06 (two chips), most likely the former and, irrespective of which it is, the reason why you cannot get it into AT mode is because it is in AT mode by default, and stays in AT mode until you connect via wireless. This also explains the absence of the button. Knowing what is what determines which way you go, since you have three Blueteeth but only need two and use the following logic trail

  1. Blueteeth never need be made into a slave unless was previously made into a master.

  2. An HM-01 can be made to converse with another HM-10 - master/slave - but neither will talk to an HC-0x, ever

  3. An HC-05 master can converse with an HC-06 slave or another HC-05. slave.

If ALL your boards are ZS-040, I think that covers it. My notes only cover data to outside world. For Arduino<>Arduino, either by HM-10<>HM-01 or HC-0x<>HC-0x, check the Martyn Currey website.