Usage of callback functions, BLE exyample

Projects Programming
1

Hi,

I have a question and I hope you can help me with that. I´m working with an Adafruit nRF52 Feather.

I´m developing a small Bluetooth Low Energy application and as basic I use the following code for Arduino:

I would like to know the connection state of my device. If a smartphone is connected to it via BLE or not. For this, in the linked code are two functions (I hope this is for that):

  • void connect_callback(uint16_t conn_handle)
  • void disconnect_callback(uint16_t conn_handle, uint8_t reason)

Now, in my loop I implemented it like this:

void loop()
{
  if (connect_callback) {
    connect = true;
  }
    else {
    connect = false;
  }
}

Unfortunaly the variable "connect" is always true, event if I connect with my smartphone or not...

I think I do something wrong in using this functions....could you say me WHAT?

Thanks in advance.

Simon

2

The callback functions are invoked by the library, not your code. Set your connect variable in the callbacks and check it in loop.

3

You did not use connect_callback as a function. Code snippets are no good. Please show ALL of your code.

http://snippets-r-us.com

4

If you look at the sample: you have to share the address of the callback function that you made with the library: this is done in the line below.

   Bluefruit.Periph.setConnectCallback(connect_callback);

And of course, this function must exist in your sketch as it exits in the example:

// callback invoked when central connects
void connect_callback(uint16_t conn_handle)
{  // Get the reference to current connection  
  BLEConnection* connection = Bluefruit.Connection(conn_handle);
  char central_name[32] = { 0 };  
  connection->getPeerName(central_name, sizeof(central_name));
  Serial.print("Connected to ");  
Serial.println(central_name);
}

If you want to know if you are connected set a flag in this function.
connect_callback is a function pointer, it contains the address of the function therefore it is always not 0 if the function exits in your sketch.
Best Regards,
Johi.

5

Hi,

thanks to you all.

I did it like wildbill said and set the variable in the callback-functions. This works very simple :slight_smile:

Thanks for your help!

6

Hi,

I have a similar question, maybe you can help me also with that.

I also have to know, when the device is advertising. For this, in the function

void startAdv(void)

is a line of the following code:

  Bluefruit.Advertising.addFlags(BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE);

But how do I get the boolean value from this, if the device is advertising or not? I´m not sure, how this works...

I attached my hole code.

I hope you can help me with that. Thanks in advance.

Simon

FactoryTest6.ino (19.7 KB)

7

This topic was automatically closed 120 days after the last reply. New replies are no longer allowed.