Hello! I've been trying for a few days to set up 2 HC05 modules to connect with each other. However, I'm unable to get the two modules to fully pair up with each other.
Hardware:
2 Arduino Nanos, one official, the other a knockoff using the old bootloader.
2 standard 6-pin HC05 breakout boards
What I have done so far:
So far I've had lots of luck with setting up each of the modules, after sending a blank sketch to each arduino, reversing the tx and rx connections (tx to tx, rx to rx), and connecting the EN pin, both modules successfully enter AT mode and I can change the settings, below are photos of the fully set-up master and slave consoles.
Master:
After uploading the settings to each HC05 modules, I revert the wiring to what I have in the drawing (rx to tx, tx to rx) and then upload a simple sketch that starts up the serial connection
void setup() {
Serial.begin(38400);
int state = 20;
}
void loop() {
if(Serial.available() > 0){ // Checks whether data is comming from the serial port
int state = Serial.read(); // Reads the data from the serial port
}
}
The problem:
This is where my success runs short, each module refuses to enter the "paired" mode where the on-breadboard LEDs flash together in short pulses. At this point, I've checked my wiring plenty of times- but I can't figure out what I am doing wrong. Are my modules busted? Am I missing something? Please help.
Ryanwew:
So far I've had lots of luck with setting up each of the modules, after ......... reversing the tx and rx connections (tx to tx, rx to rx), and connecting the EN pin, both modules successfully enter AT mode and I can change the settings,
Really? I'm betting you haven't, and that is where the problem lies. For all that, you might check the Martyn Currey website to get the real deal. He specifically refers to Nanos. I don't think the slave HC-05 needs any configuration, indeed an HC-06 will suffice.
Nick_Pyner:
Really? I'm betting you haven't, and that is where the problem lies.
I know that the HC-05 modules are wired correctly because they do not enter this state when wired wrong, and I have wired them wrong a handful of times. Furthermore, the modules reply to all commands sent through the console and save all information in between disconnections (they still have the same role and bonded address after completely restarting power). See my posted master and slave console imigur links, let me know if anything looks off.
Nick_Pyner:
For all that, you might check the Martyn Currey website to get the real deal. He specifically refers to Nanos. I don't think the slave
However, the tutorials are very out of date and no longer work. "There are now newer modules that use a 3.0-20170601 firmware. This guide does not work for these modules (AT+INQ gives an error)" indeed many of the commands from the tutorial return error(16), including AT+LINK and AT+INQ. Do you have any experience with newer modules?
Nick_Pyner:
I don't think the slave HC-05 needs any configuration, indeed an HC-06 will suffice.
I know the slave doesn't need configuring, I just wanted to make sure that I included all details of my issue. This is my first post, sorry if it's a little over-detailed.
As for the HC06, is it necessary, or can I find a way to work with the HC05s that I have now.
Thanks for the tips, hopefully, I can get them to eventually work.
p.s. I've swapped to using SoftwareSerial so I don't have to rewire all the time, should I still have the connections reversed (tx to rx) or vice versa?
However, the tutorials are very out of date and no longer work. "There are now newer modules that use a 3.0-20170601 firmware. This guide does not work for these modules (AT+INQ gives an error)" indeed many of the commands from the tutorial return error(16), including AT+LINK and AT+INQ. Do you have any experience with newer modules?
I know the slave doesn't need configuring, I just wanted to make sure that I included all details of my issue. This is my first post, sorry if it's a little over-detailed.
As for the HC06, is it necessary, or can I find a way to work with the HC05s that I have now.
No, the first image looks exactly as it should be - Tx>Rx and Rx<Tx - and if you understand what Tx and Rx actually mean, there should be no surprise there. Further, there is no need to change the wiring for AT mode. Needless to say, software serial is used the same way. If you move to software serial, which is hardly a good idea at this juncture, it might be a good idea to get off the 38400 and use 9600 instead.
It is not necessary to use HC-06
I do not have direct experience with the V3-2017 version, but it is pretty clear that they are more trouble than they are worth, and should be avoided like the plague. Unfortunately, I don't know how you can do that. The problems with them are only manifest in AT mode. You are probably already aware that some AT commands can only be executed by using the EN pin, not by button, but I don't think that will save you in this instance.
Your post is fine but there are instructions for inserting pictures directly into your post.
Nick_Pyner:
Further, there is no need to change the wiring for AT mode.
I just tested that, AT mode only works then the wires are connected as TX > TX and not reversed as you said.
Nick_Pyner:
I do not have direct experience with the V3-2017 version, but it is pretty clear that they are more trouble than they are worth, and should be avoided like the plague. Unfortunately, I don't know how you can do that. The problems with them are only manifest in AT mode. You are probably already aware that some AT commands can only be executed by using the EN pin, not by button, but I don't think that will save you in this instance.
Most of the tutorials online show using the new HC05 modules as effortless, I don't see why you think using them is difficult. Unless those tutorials are simply lying, I'm making a mistake and that is causing my troubles. I will be ordering a new pair of HC05 modules, at this point, I've checked over everything and can't find any mistakes. Everything is working, but I just can't get them to connect. If even new modules don't work, at that point I will look into a new module- If I do have to resort to that, what do you suggest for short-range (30 ft max) wireless communication?
Nick_Pyner:
Your post is fine but there are instructions for inserting pictures directly into your post.
I tried inserting photos into my post, but I got an error saying my post exceeded the character limits. Can you send me the instructions?
Ryanwew:
I don't see why you think using them is difficult. Unless those tutorials are simply lying,
Well, they could be. There is a lot of that about, and connecting a receiver to a receiver makes no sense whatsoever. I say this specifically because the V3 HC-05s are on the same breakout boards that have been around for some years. However, if Groundfungus says it's kosher, I will go along with it. This particularly as he is apparently succeeding in doing exactly what you are trying to do, and failing, and using the same references.
I point out that V3s are fine until you go into AT mode, which most users probably don't, and even then the problems don't necessarily arise because some or most of the AT instructions are OK. Nonetheless, there are enough people on this forum that have had grief of varying sorts to confirm that V3s are a right royal pain in the arse. I also understand that the problems with V3s are inconsistent, but that may be user perception.
If I do have to resort to that, what do you suggest for short-range (30 ft max) wireless communication?
You might look at the HM-10. It is a BLE device but operationally more akin to an HC-05. The AT command set is limited, by BLE standards, but may be adequate for your needs. I have had very little experience with it but was surprised to find that, apart from requiring a BLE-compatible terminal, it worked just like an HC-05.
The price and range are about the same. I have never heard any proper claims of BLE devices being duds or fakes, which is more than can be said for HC-05s these days.
