Error(-22) on connecting to the peripheral using nrf52840 as central

[Karthik p]

Hi 

this is the error when I tried to connect to peripheral and also get the error on scanning after that connection error 

I am using the sample code for this application https://docs.zephyrproject.org/latest/samples/bluetooth/central_hr/README.html

[Amanda Hsieh]

Hi, 

Please program the peripheral with https://docs.zephyrproject.org/latest/samples/bluetooth/peripheral_hr/README.html 

Regards,
Amanda H.

[Karthik p]

#include <zephyr/kernel.h>
#include <zephyr/bluetooth/bluetooth.h>
#include <zephyr/bluetooth/conn.h>
#include <zephyr/bluetooth/gatt.h>
#include <bluetooth/scan.h> 

static struct bt_conn *default_conn;  // Use a more descriptive name

static void device_found(const bt_addr_le_t *addr, int8_t rssi,
                          uint8_t adv_type, struct net_buf_simple *buf) {
    int err;
    char addr_str[BT_ADDR_LE_STR_LEN];

    bt_addr_le_to_str(addr, addr_str, sizeof(addr_str));
    printk("Device found: %s (RSSI %d)\n", addr_str, rssi);

    // Handle connection logic (consider adding filtering or selection)
    if(!strcmp(addr_str,"00:18:80:00:BD:02 (public)")){
    err = bt_conn_le_create(addr, BT_CONN_LE_CREATE_CONN,
                            BT_LE_CONN_PARAM_DEFAULT, &default_conn);
    if (err) {
        printk("Error connecting: %d\n", err);
    } else {
        // Successfully connected, handle connection established event
        printk("Connected to: %s\n", addr_str);
        bt_scan_stop();
        return;
        // (Add further actions for the connected device here)
    }
    }
}

static void scan_start(void) {
    int err;

    err = bt_le_scan_start(BT_LE_SCAN_PASSIVE, device_found);
    if (err) {
        printk("Error starting scan: %d\n", err);
    }
}

void main(void) {
    int err;

    err = bt_enable(NULL);
    if (err) {
        printk("Error enabling Bluetooth: %d\n", err);
        return;
    }

    scan_start();

    // Add a loop or blocking call to keep the program running
    while (1) {
        k_sleep(K_MSEC(1000));  // Sleep for 1 second
    }
}

this is the code I am running here I my not discovering the service 

I am just trying to connect using the MAC id 

BR 

Karthik P 

[Amanda Hsieh]

Hi, 

Karthik p said:

what's the meaning of error -22 and why this error occurs.

error -22 means Invalid argument returned by bt_conn_le_create. 

error -120 for is EALREADY means Socket already connected returned by bt_le_scan_start.

Karthik p said:

I am just trying to connect using the MAC id 

You can use the function bt_scan_filter_add(..) and provide the scan filter type BT_SCAN_FILTER_TYPE_ADDR along with the address. After scanning, you can match the filter (which can be the MAC ID) using the `scan_filter_match` function. Take a look at the nrf_desktop application and central_nfc_pairing for guidance on how to implement this. Here is the tutorial for scanning and connecting. 

-Amanda H.

[Karthik p]

Thank you