Hi,
A few days ago, I tried to change the name of the HC05 Bluetooth module
via AT commands using the method shown in the picture, and I was able to change it, but when I tried to use it with the phone to control a robot or something else, it appeared in the list of available Bluetooth devices and I was able to pair, but after that I was unable to connect, noting that I tried all the methods to exit AT command mode and most of the time it was in normal mode, but I did not understand the reason for the problem.
Hello,
What do you mean by
And are you sure your wiring is good? You linked both of the TX together on your schematic. Is this the way you can communicate with the HC05?
i meant that can pair the bluetooth HC05 with my phone but when i try to connect it with my app, i can't knowing that the app work well with other bluetooth modules.
Concerning the wiring, i agree with you that the Tx should be connected to Rx and opposite but i tried this wiring and it worked for me when trying to get access to AT mode.
Before changing the name of the device, did you "forget" the module on your phone? Maybe now you have two device with different name but same MAC address which could be confusing for your app
yes, i did it many times
Me neither. Did you try to set the old name?
Can you try to connect with another phone?
True, i didn't tried to connect it with another phone.
I connected it to another phone and i got the same problem
And you can exchange AT command with the module?
BTW, you're supposed to have a voltage divider on the RX pin of the module. Check on the WEB
Also, I recommand using other pins that 0 and 1, that are used by the Arduino to communicate with the computer
yeah, the AT commands work
Quelle est la fréquence de la LED sur le module ?
Essai de l'alimenter depuis une source externe. Pense à mettre un GND commun
on my HC05 module I put a switch between VCC and EN, because when you work in AT mode they must be connected, while when you work in normal mode they are not
I successfully entered AT mode on my HC-05 Bluetooth module (version: hc05V2.3_le) using an Arduino Uno and changed the module name using AT+NAME. However, after that:
The module appears in the phone's Bluetooth list and pairs automatically without asking for a PIN
Once paired, I can’t connect or communicate with it using any Bluetooth Serial app
I tried with two phones (Android), same issue
What I Tried:
Confirmed AT mode using AT → got OK
Tried AT+PSWD=1234 → got FAIL
Tried AT+PIN=1234 → got no response
Tried AT+CMODE=1 → got FAIL
Reset with AT+ORGL → worked, but issue persisted
Checked firmware: AT+VERSION? → +VERSION:hc05V2.3_le
After reset, module still pairs instantly, no PIN prompt, and won’t send/receive data
Wiring is correct, baud rate is 38400 in AT mode, using Arduino with SoftwareSerial.
I was able to change the password using 6-digit password but the problem of connecting it to my phone app is not working
What is the actual wiring you have?
Is the EN pin (seems to be called Key on your schematic) linked to Vcc or no?
If yes, try to put it to low, and send again the AT+RESET cmd
Is software serial viable at 38400 baud?
Why wouldn't it? I never got any problem with software serial; at least at 19200bps
The hardware serial uses a UART but software serial uses 'bit banging' so the processor needs more time to process each character.
Please post a link to where you bought the modules. They are mislabeled and don't work as advertised. They appear to have BLE code on them. See this thread:
So it will not work ?
The module was falsely advertised and will not do what you want it to do.
Please post a link to where you bought the modules, so others can avoid making that mistake.