Multiple notifications on central side

[DevBear]

Hello!

I am trying to set up a central that accepts notifications for two different attributes from a custom BLE service.

I know that the problem is in my discovery process seen below, and I have managed to figure out that it is either in the:

discover_params.start_handle = attr->handle   part of the code OR it is in how I handle my switch if-statements.
I have watched this post How to enable multiple notifications in central side that had the same issue as me however I can't seem to get it right.

All sample code that I have looked at on the central side does not handle multiple notifications/multiple attributes so they haven't helped me.

Note 1: I don't want to use the discovery manager so please don't suggest this.

Note 2: Everything from the peripheral works fine with the NRF Connect app so the peripheral is not the issue here.

 

static uint8_t discover_func(struct bt_conn *conn,
			     const struct bt_gatt_attr *attr,
			     struct bt_gatt_discover_params *params)
{
	int err;

	if (!attr) {
		printk("Discover complete\n");
		(void)memset(params, 0, sizeof(*params));
		return BT_GATT_ITER_STOP;
	}

	printk("[ATTRIBUTE] handle %u\n", attr->handle);

	if (!bt_uuid_cmp(discover_params.uuid, BT_UUID_FROG)) {
		printk("Discovering TxDATA\n");
		memcpy(&frog_discover_uuid, BT_UUID_TXDATA, sizeof(frog_discover_uuid));
		discover_params.uuid = &frog_discover_uuid.uuid;
		discover_params.start_handle = attr->handle + 1;
		discover_params.type = BT_GATT_DISCOVER_CHARACTERISTIC;

		err = bt_gatt_discover(conn, &discover_params);
		if (err) {
			printk("Discover failed (err %d)\n", err);
		}
	} else if ((!bt_uuid_cmp(discover_params.uuid, BT_UUID_FROG))) {
		printk("Discovering RxCREDIT\n");
		memcpy(&frog_discover_uuid, BT_UUID_RXCREDIT, sizeof(frog_discover_uuid));
		discover_params.uuid = &frog_discover_uuid.uuid;
		discover_params.start_handle = attr->handle + 2;
		discover_params.type = BT_GATT_DISCOVER_CHARACTERISTIC;

		err = bt_gatt_discover(conn, &discover_params);
		if (err) {
			printk("Discover failed (err %d)\n", err);
		}
	} else if (!bt_uuid_cmp(discover_params.uuid, BT_UUID_TXDATA)) {
		printk("Discovering CCC TxData\n");
		discover_params.uuid = ccc_uuid;
		discover_params.start_handle = attr->handle + 3;
		discover_params.type = BT_GATT_DISCOVER_DESCRIPTOR;
		subscribe_params.value_handle = bt_gatt_attr_value_handle(attr);

		err = bt_gatt_discover(conn, &discover_params);
		if (err) {
			printk("Discover failed (err %d)\n", err);
		}
	} else if (!bt_uuid_cmp(discover_params.uuid, BT_UUID_RXCREDIT)){
		printk("Discovering CCC RxCredit\n");
		discover_params.uuid = ccc_uuid2;
		discover_params.start_handle = attr->handle + 4;
		discover_params.type = BT_GATT_DISCOVER_DESCRIPTOR;
		subscribe_params.value_handle = bt_gatt_attr_value_handle(attr);

		err = bt_gatt_discover(conn, &discover_params);
		if (err) {
			printk("Discover failed (err %d)\n", err);
		}
	} else {
		subscribe_params.notify = notify_func;
		subscribe_params.value = BT_GATT_CCC_NOTIFY;
		subscribe_params.ccc_handle = attr->handle;

		err = bt_gatt_subscribe(conn, &subscribe_params);
		if (err && err != -EALREADY) {
			printk("Subscribe failed (err %d)\n", err);
		} else {
			printk("[SUBSCRIBED]\n");
		}

		return BT_GATT_ITER_CONTINUE;
	}

	return BT_GATT_ITER_STOP;
}

Thank you in advance and please let me know if I need to clarify or add some more information.

//Björn