soft-UART problems reciving data from HC-05 device

[gamerse]

Hi every one.

Info:
Arduino ATmega2560
HC-05 Device (slave) - Default Baud: 9600

I need to be able to send data from my phone (android) via bluetooth. I use an app on the phone called: Simple Bluetooth terminal.
But i can’t recive anything…

I know that the module is correctly set up and configured.
Since I can send and receive data in Arduino IDE via serial monitor
see the pictures below:

I’ve tried copying someone else’s setup from a post on the same forum:

Link to the forum: HC-05 UART Communication

Here is the setup I made in XOD, however I can’t get it to work:

I have also tried this way, but without success:

I hope someone can help me further. It is to be used for a school project.
If you need more information, I will try to answer as soon as possible.

Thanks in advance

[wayland]

Hi @gamerse,

The Arduino Mega has four serial ports, so there is no need to use software serial (soft-uart). In any case, pins D18 and D19 on the Arduino Mega cannot be used for software serial (see: https://docs.arduino.cc/learn/built-in-libraries/software-serial).

Replace the soft-uart node with the uart-1 node. The uart-1 node corresponds to the 2nd serial port on your Arduino Mega (D18=TX1, D19=RX1). I don’t have a HC-05 device, so I can’t test your patch.

Hope this helps!

[gamerse]

Hello @wayland and thanks for the fast response!

I have tested it as you suggested:

Now I can at least see that I am receiving a signal from my phone to the arduino.

When I send the number 50. The number changes from 0 to 10 in the Watch node. But the value always shows 10. even if I send other values ​​from my phone se pictures.

Any idea what could be the problem?
Many many thanks for the help

[gamerse]

I just tested it both ways.

Using Read-line I can only receive the value if it is sent twice.

Any idea what could be causing this?

[gweimer]

How many bytes are being sent? If more than one byte is sent, one read-byte node isn’t going to clear the is-available to cause it to pulse again.

I don’t see read-line built-in to XOD. It implies reading until a newline character, which may or may not get sent (maybe it just reads available bytes and returns string).

You could look into using read-bytes, even if only as a test to verify what is being sent. You could use clock to pulse read-bytes-READ every few seconds and see how many times output updates for a single message you are sending.

[gamerse]

I will try it out.

Thank you for the input