W: conn failed to establish. RF noise?

RE: W: conn failed to establish. RF noise?

Susheel Nuguru — Tue, 13 May 2025 11:25:12 GMT

Assuming that you are able to reproduce this on DK, Can you please attach your minimalistic project so that I can reproduce this on my desk and find out the reason for this. This will avoid a lot of ping pong questions and let me dive straight to debugging.

RE: W: conn failed to establish. RF noise?

Susheel Nuguru — Wed, 07 May 2025 11:15:50 GMT

There is a bug in your code, in the connected_cb() you are not giving the semaphore when the connection fails.

So when there is a connection failure your main loop is stuck. You also still have k_sem_take waiting for K_FOREVER.

I suggest you one of the two changes

1) In your connected_cb()

static void connected_cb(struct bt_conn *conn, uint8_t err)
{
    if (err) {
        LOG_ERR("Connection failed (err 0x%02x)", err);
        bt_conn_unref(conn);
        k_sem_give(&sem_connected);    // ADD THIS NEW LINE ADDED SUSHEEL
        return;
    }

    /* On success the same give(), which you are doing already. */
    k_sem_give(&sem_connected);
    …
}

2) Make sure your k_sem_take are not waiting for ever and PLEASE DO NOT IGNORE RETURN VALUES of function calls like k_sem_take

RE: W: conn failed to establish. RF noise?

NickDeLeenheer — Tue, 06 May 2025 13:41:18 GMT

deleted

RE: W: conn failed to establish. RF noise?

Susheel Nuguru — Tue, 06 May 2025 07:38:20 GMT

Yes, Please share you whole project zipped. I need to see what your code is doing in other callbacks like connected(). I also need to see how you are giving the semaphore sem_connected.

RE: W: conn failed to establish. RF noise?

NickDeLeenheer — Mon, 05 May 2025 20:45:40 GMT

deleted

RE: W: conn failed to establish. RF noise?

Susheel Nuguru — Mon, 05 May 2025 09:46:25 GMT

Also please do not open multiple threads on the same issue and please close on of these two threads.

RE: W: conn failed to establish. RF noise?

Susheel Nuguru — Mon, 05 May 2025 09:45:25 GMT

Isn't this the same issue as mentioned here ?

Yes, the infinite loop seems wrong like you already suspected and it is better to have a timeout and move on. I suggest the below for the cleanup code

if (k_sem_take(&sem_connected, K_SECONDS(4)) != 0) {
    printk("W: Connection to device %d timed out. Skipping...\n", i);
    if (connections[i]) {
        bt_conn_disconnect(connections[i], BT_HCI_ERR_REMOTE_USER_TERM_CONN);
        bt_conn_unref(connections[i]);
        connections[i] = NULL;
    }
    continue; // Move on to the next device
}

RE: W: conn failed to establish. RF noise?

NickDeLeenheer — Mon, 05 May 2025 08:23:47 GMT

deleted

RE: W: conn failed to establish. RF noise?

Susheel Nuguru — Mon, 05 May 2025 05:35:02 GMT

Hi Nick,

Can you please tell us more on your test setup and also show us the console output where you see the warning you mentioned? It sounds like a configuration issue with the software but I can try to assist you more after you provide more information that I requested.