Can connect to uart_peripheral by UUID, but can't connect to a non-Zephyr product

[DiBosco]

I have managed to get, somehow, a central_uart talking to a peripheral_uart on a pair of  52840 DKs.

I've changed the UUIDs of what I'm trying to connect to, to be those of a different device that has BLE in it.

I've previously connected to this using an RPi and its UART, getting data in and out of it. So I went PC UART <-> Rpi BLE <-> Other Unit

Am trying to repeat that but using the 52840 DK

I've taken the central UART project and changed the code  do to this:

#define XLRT_SERVICE_UUID_VAL \

BT_UUID_128_ENCODE(0x2a1f963c, 0x143a, 0x4f7d, 0x9107, 0x6315196a02a6)

/** @brief UUID of the TX Characteristic. **/

#define XLRT_TX_UUID_VAL \

BT_UUID_128_ENCODE(0x651135b0, 0xdfe9, 0x45a2, 0x95c1, 0x46552a8a77e2)

/** @brief UUID of the RX Characteristic. **/

#define XLRT_RX_UUID_VAL \

BT_UUID_128_ENCODE(0xe7d6274e, 0xb765, 0x11e9, 0xa2a3, 0x2a2ae2dbcce4)

#define BT_UUID_XLRT_SERVICE BT_UUID_DECLARE_128(XLRT_SERVICE_UUID_VAL)

#define BT_UUID_XLRT_RX BT_UUID_DECLARE_128(XLRT_RX_UUID_VAL)

#define BT_UUID_XLRT_TX BT_UUID_DECLARE_128(XLRT_TX_UUID_VAL)

Previously this worked fine connecting to the peripheral_uart example project running on the second 52840DK. The only thing I have done is change the UUIDs of the service I want to connect to and the the UUIDs of the two characteristics that I want to read from  and write to.

Can you think of any reason why it would connect to the DK running peripheral_unit and not this other unit? The other unit has an older chip in, using SES and has   the same types od read/write characteristics.

I would expect it to simply connect to the unit because the service UUID matches, even if the BLE data might not get to/from at first due to some other bug in the code. I'm nevere getting the call to function:

static void connected(struct bt_conn *conn, uint8_t conn_err)

Which I do if I try to connect to peripheral_uart.

Thanks

[Vidar Berg]

Please use the nRF connect app to confirm that the peripheral is including the service UUID in its advertisment payload:

DiBosco said:

I would like to try connecting via a MAC address instead, but there's no documentation about the syntax. I've asked on separate thread and ther was a suggestion that ignored the syntax issue and I've not heard back on that for a day or so.

I haven't read the other ticket, but you can search the SDK tree for 'BT_SCAN_FILTER_TYPE_ADDR' to find examples of where the address filter is used. 

	bt_addr_le_t addr = {
		.type = BT_ADDR_LE_RANDOM,
		.a.val = {0x62, 0x21, 0x24, 0xDB, 0xA0, 0xE8},
	};

[DiBosco]

Vidar Berg said:

Please use the nRF connect app to confirm that the peripheral is including the service UUID in its advertisment payload:

OK, that may be the issue, as it looks like it is not:

[Vidar Berg]

That explains why you don't get a filter match. The Service UUID is added to the scan response packet in the sample code here:

You can try using the name or address filter instead. I believe this matches your address configuration:

	bt_addr_le_t addr = {
		.type = BT_ADDR_LE_RANDOM,
		.a.val = {0x62, 0x21, 0x24, 0xDB, 0xA0, 0xE8},
	};

[DiBosco]

This:

#ifdef SCAN_BY_SERVICE_UUID

err = bt_scan_filter_add(BT_SCAN_FILTER_TYPE_UUID, BT_UUID_XLRT_SERVICE);

#else

bt_addr_le_t addr = {

.type = BT_ADDR_LE_RANDOM,

.a.val = {0x62, 0x21, 0x24, 0xDB, 0xA0, 0xE8},

};

err = bt_scan_filter_add(BT_SCAN_FILTER_TYPE_ADDR, &addr);

#endif

Gives me this result:

[00:00:00.025,451] <0x1b>[1;31m<err> central_uart: Scanning filters cannot be set (err -12)<0x1b>[0m␍␊

[00:00:00.025,451] <0x1b>[1;31m<err> central_uart: scan_init failed (err -12)<0x1b>[0m␍␊

This:

BLE scan filter by device name

Makes me think maybe I have to add something to prj.conf?

CONFIG_BT_SCAN_FILTER_ENABLE=y

CONFIG_BT_SCAN_UUID_CNT=1

I have the above, but maybe there's something I need to add along the lines of

CONFIG_BT_SCAN_ADDR_CNT=1

It throws a wobbler if I try that even though this page:

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/v1.6-branch/kconfig/CONFIG_BT_SCAN_ADDRESS_CNT.html

Suggests that's a valid thing.

[Vidar Berg]

Forgot to add that you need to add CONFIG_BT_SCAN_ADDR_CNT=1 to your project configuration (prj.conf). Then it should work. Which SDK version are you testing with?