HC-05 in at mode but dont answer my request [Solved]

I have an HC-05 but and the module is in AT mode. I can see the LED blinking slowly but when I send an AT command i dont get any answer. Can somebody help me?

Moderator: Title edited

Send more details. Schematics etc....

all there

David_Pires:
http://www.instructables.com/id/How-to-Configure-HC-05-Bluetooth-Module-As-Master-/

all there

And that "tutorial" is all wrong.

I have a HC-05 module and I think I´m in AT mode the Led on the board is blinking slowly, like 2 secons ON next two seconds OFF. But when I send some commands I got no answer back pls help me, I need to know the adress from the bluetooth module to connected it with a shield.

This is my wiring:

I have double checked the wiring and I have everything connected like Im supposed to...
Key -> Pin 2
Vcc -> 5v (My module supports from 3.6v to 6v)
Gnd -> Arduino Gnd
Txd -> Pin 3
Rxd -> Pin 4
State -> Nothing cause im not using it.

This is the code:

#include <SoftwareSerial.h>

SoftwareSerial serial2(3,4);

void setup(){
Serial.begin(9600);
serial2.begin(38400);

pinMode(2,OUTPUT);
digitalWrite(2,HIGH);

Serial.print("AT Commands");

}

void loop(){
if(Serial.available())
serial2.write(Serial.read());

if(serial2.available())
Serial.write(serial2.read());
delay(200);
}

My HC-05 module:

https://lh3.googleusercontent.com/VUkOFY-JpizP5igBIftCabtgG4ITsunU_Ax7a97u52b47CjHXbHCiLFyDk6hAqNJEMzUvA=s85

My shield:

You don't need to start a new post for the same problem!

Continue the discussion at HC-05 in at mode but dont answer my request [Solved] - #3 by David_Pires - Networking, Protocols, and Devices - Arduino Forum

.

You had better sort out what you are talking about and merge your posts. In your other thread, you specifically refer to an HC-06. Once you have that sorted, you might have a look at the Martyn Currey site. He knows what he is doing - a state of affairs not common in Instructables. Your problem may be no more than a matter of properly formatting the AT commands.

So I have seen Martyn currey site but i can´'t solve the problem With my HC-05 module so I have made some test with my smartphone, I can connect to the module and receive values sended on my smartphone but I cant send values from my device to the arduino by the module.

When values froma arduino are send by the module for my smartphone the TX LED blinks when i try to send from smartphone nothing happens

Is my module damaged?

:frowning: >:( >:(

David_Pires:
I have made some test with my smartphone, I can connect to the module and receive values sended on my smartphone but I cant send values from my device to the arduino by the module.

When values froma arduino are send by the module for my smartphone the TX LED blinks when i try to send from smartphone nothing happens

This is utterly unintelligible, but HC-0x are pretty robust and there is nothing to suggest you have damaged it. About the worst that has happened is that you have actually succeeded in sending AT commands without being aware of it.

If you can refrain from getting into AT commands for the moment, you might 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

I still dont have no solution and I woul try ask you guys if the module needs a resistor dividor on RX I see some guys using I dont try it because I Have to buy the resistor is the resistor dividor required?

Thank You

Nobody should tell you you don't need it, but plenty of people get away without it.

Thank you again, I cant find my problem. I will continue searching.

Mar 30, 2018, 05:04 pm
I have an HC-05 but and the module is in AT mode. I can see the LED blinking slowly but when I sen an AT command i dont get any answer. Can somebody help me?

Recently, I have bought two HC05s. They work well in terms of inter communication; but, they don't accept AT commands.

I have one more HC05 which I have borrowed (before purchasing the later two HC05s) from my friend. It is good, and it takes AT command. This good one and other two suspected modules are looked identical; all three have the same micro switches on-board to bring them into AT Modes. The good one responses to micro switch activation; but, the other twos do not care!! I think these are cheap Chinese colons and they have not implemented the circuitry for the AT command in order to save money.

Oh so maybe I cant solve the problem at all. Nice so I need some lucky when I buy a HC-05, so tell me your friend bought the good HC-05 where maybe I have more lucky than in "my shop".

Help me if you can. Thank you.

I guys I solve the problem, so the problem was the RX resistor dividor, I wasnt using it so i talk to Martyn Currey in him website and he told me to put the resistor and now its working thank you all you guys.

Glad to hear it is working, but it has nothing to do with the divider. While it is good practice to use a divider, you can have an HC-05 running perfectly for years without it. You can be quite sure that, if you fixed things now, the real problem was just sloppy wiring.