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samples: bluetoot: connect directly to 1ms
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Instad of connecting to 7.5ms and then changing to 1ms.
Speeds up encryption setup and service discovery by alot.

Signed-off-by: Martin Tverdal <martin.tverdal@nordicsemi.no>
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@martintv @rlubos
martintv authored and rlubos committed Aug 11, 2023
1 parent cce2a4d commit 0520999
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188 changes: 110 additions & 78 deletions samples/bluetooth/llpm/README.rst
View file
Original file line number Diff line number Diff line change
Expand Up @@ -106,33 +106,32 @@ After programming the sample to both development kits, test it by performing the

- The central outputs the following information::

Press any key to set LLPM short connection connection interval (1 ms)
Press any key to start measuring transmission latency

- The peripheral outputs the following information::

Press any key to start measuring transmission latency

#. Press a key in the terminal that is connected to the peripheral.
#. Observe the terminal connected to the peripheral. The latency measurements are printed in the terminal.
The latency is expected to be shorter than the default connection interval::
#. Observe the terminal connected to the peripheral.
The latency measurements are printed in the terminal.
The latency is expected to be around 1 ms.

Transmission Latency: 80917 (us), CRC mismatches: 0
Transmission Latency: 1083 (us), CRC mismatches: 0

#. Press a key in the terminal that is connected to the central.
#. Observe the connection gets updated to LLPM connection interval (1 ms) on both sides::

Connection interval updated: LLPM (1 ms)

#. Observe the terminal connected to the peripheral.
The measured latency on the peripheral becomes approximate 1 ms::

Transmission Latency: 1098 (us), CRC mismatches: 0

#. Press a key in the terminal that is connected to the central.
#. Observe the central switches to standard 7.5 ms interval right after performing latency measurements.

#. Observe the terminal connected to the central.
The measured latency on the central remains approximate 1 ms::
The latency is higher now.

Transmission Latency: 1235 (us), CRC mismatches: 0
Connection interval updated: 7.5 ms
Transmission Latency: 4592 (us), CRC mismatches: 0

.. msc::
hscale = "1.3";
Expand Down Expand Up @@ -162,99 +161,132 @@ The result should look similar to the following output.

- For the central::

***** Booting Zephyr OS build v1.14.99-ncs3-snapshot2-2647-gd6e67554cfeb *****
*** Booting Zephyr OS build v3.3.99-ncs1-2858-gc9d01d05ce83 ***
Starting Bluetooth LLPM example
I: SoftDevice Controller build revision:
I: 01 2d a8 d4 0d e5 25 cf |.-....%.
I: a3 48 8d 2f 56 e0 59 c8 |.H./V.Y.
I: 24 df 3d 58 |$.=X
I: HW Platform: Nordic Semiconductor (0x0002)
I: HW Variant: nRF52x (0x0002)
I: Firmware: Standard Bluetooth controller (0x00) Version 1.43053 Build 635768276
I: Identity: FF:FA:56:08:E1:DD (random)
I: HCI: version 5.4 (0x0d) revision 0x10b7, manufacturer 0x0059
I: LMP: version 5.4 (0x0d) subver 0x10b7
Bluetooth initialized
LLPM mode enabled
Choose device role - type c (central) or p (peripheral): c
Choose device role - type c (central) or p (peripheral):
Central. Starting scanning
Scanning successfully started
Connection event reports enabled
Filter not match. Address: 08:c6:a4:e0:72:e9 (random) connectable: 0
Filter not match. Address: 13:04:eb:f1:0b:46 (random) connectable: 0
Filter not match. Address: 2b:74:72:c3:8f:a8 (random) connectable: 0
Filter not match. Address: 02:ec:f9:bb:ec:27 (random) connectable: 0
Filter not match. Address: 01:54:cf:d4:31:cd (random) connectable: 0
Filter not match. Address: 3e:21:91:91:52:82 (random) connectable: 0
Filter not match. Address: 08:c6:a4:e0:72:e9 (random) connectable: 0
Filter not match. Address: 37:63:6a:ed:38:e2 (random) connectable: 0
Filter not match. Address: 56:c6:75:17:80:d8 (random) connectable: 1
Filters matched. Address: f9:3c:9c:d1:f6:07 (random) connectable: 1
Filter does not match. Address: 1F:25:BE:AC:D4:47 (random) connectable: 0
Filter does not match. Address: 5E:29:3A:8C:5A:8D (random) connectable: 0
Filter does not match. Address: 2C:E8:67:EA:C9:27 (random) connectable: 1
Filters matched. Address: C3:06:3D:25:7F:73 (random) connectable: 1
Filter does not match. Address: EA:0E:68:82:9D:0C (random) connectable: 1
Filter does not match. Address: 1B:CC:D4:7C:9E:31 (random) connectable: 0
Connected as central
Conn. interval is 80 units (1.25 ms/unit)
Conn. interval is 3329 units (1.25 ms/unit)
Security changed: level 2, err: 0
Service discovery completed
Press any key to set LLPM short connection interval (1 ms)
Press any key to start measuring transmission latency
Connection interval updated: LLPM (1 ms)
Transmission Latency: 1235 (us), CRC mismatches: 0
Transmission Latency: 1007 (us), CRC mismatches: 0
Transmission Latency: 1434 (us), CRC mismatches: 0
Transmission Latency: 1312 (us), CRC mismatches: 0
Transmission Latency: 1220 (us), CRC mismatches: 0
Transmission Latency: 991 (us), CRC mismatches: 0
Transmission Latency: 1037 (us), CRC mismatches: 0
Transmission Latency: 1296 (us), CRC mismatches: 0
Transmission Latency: 1342 (us), CRC mismatches: 0
Transmission Latency: 1419 (us), CRC mismatches: 0
Transmission Latency: 1281 (us), CRC mismatches: 0
Transmission Latency: 961 (us), CRC mismatches: 0
Transmission Latency: 1052 (us), CRC mismatches: 0
Transmission Latency: 991 (us), CRC mismatches: 0
Transmission Latency: 1403 (us), CRC mismatches: 0
Transmission Latency: 1296 (us), CRC mismatches: 0
Transmission Latency: 1342 (us), CRC mismatches: 0
Transmission Latency: 1419 (us), CRC mismatches: 0
Transmission Latency: 961 (us), CRC mismatches: 0
Transmission Latency: 1052 (us), CRC mismatches: 0
Transmission Latency: 976 (us), CRC mismatches: 0
Transmission Latency: 1358 (us), CRC mismatches: 0
Transmission Latency: 1281 (us), CRC mismatches: 0
Transmission Latency: 1296 (us), CRC mismatches: 0
Transmission Latency: 1342 (us), CRC mismatches: 0
Transmission Latency: 1419 (us), CRC mismatches: 0
Transmission Latency: 961 (us), CRC mismatches: 0
Transmission Latency: 1052 (us), CRC mismatches: 0
Transmission Latency: 976 (us), CRC mismatches: 0
Transmission Latency: 1358 (us), CRC mismatches: 0
Transmission Latency: 1281 (us), CRC mismatches: 0
Transmission Latency: 1296 (us), CRC mismatches: 0
Transmission Latency: 1342 (us), CRC mismatches: 0
Transmission Latency: 1419 (us), CRC mismatches: 0
Transmission Latency: 961 (us), CRC mismatches: 0
Transmission Latency: 1052 (us), CRC mismatches: 0
Transmission Latency: 976 (us), CRC mismatches: 0
Transmission Latency: 1358 (us), CRC mismatches: 0
Transmission Latency: 1281 (us), CRC mismatches: 0
Transmission Latency: 1296 (us), CRC mismatches: 0
Transmission Latency: 1342 (us), CRC mismatches: 0
Transmission Latency: 1419 (us), CRC mismatches: 0
Transmission Latency: 961 (us), CRC mismatches: 0
Connection interval updated: 7.5 ms
Transmission Latency: 1922 (us), CRC mismatches: 0
Transmission Latency: 7064 (us), CRC mismatches: 0
Transmission Latency: 13244 (us), CRC mismatches: 0
Transmission Latency: 4592 (us), CRC mismatches: 0
Transmission Latency: 7019 (us), CRC mismatches: 0
Transmission Latency: 5691 (us), CRC mismatches: 0
Transmission Latency: 4592 (us), CRC mismatches: 0
Transmission Latency: 7019 (us), CRC mismatches: 0
Transmission Latency: 5706 (us), CRC mismatches: 0
Transmission Latency: 4577 (us), CRC mismatches: 0
Transmission Latency: 7019 (us), CRC mismatches: 0
Transmission Latency: 5706 (us), CRC mismatches: 0
Transmission Latency: 4592 (us), CRC mismatches: 0
Transmission Latency: 7019 (us), CRC mismatches: 0
Transmission Latency: 5691 (us), CRC mismatches: 0
Transmission Latency: 4592 (us), CRC mismatches: 0
Transmission Latency: 7019 (us), CRC mismatches: 0
Transmission Latency: 5706 (us), CRC mismatches: 0

- For the peripheral::

***** Booting Zephyr OS build v1.14.99-ncs3-snapshot2-2647-gd6e67554cfeb *****
*** Booting Zephyr OS build v3.3.99-ncs1-2858-gc9d01d05ce83 ***
Starting Bluetooth LLPM example
I: SoftDevice Controller build revision:
I: 01 2d a8 d4 0d e5 25 cf |.-....%.
I: a3 48 8d 2f 56 e0 59 c8 |.H./V.Y.
I: 24 df 3d 58 |$.=X
I: HW Platform: Nordic Semiconductor (0x0002)
I: HW Variant: nRF52x (0x0002)
I: Firmware: Standard Bluetooth controller (0x00) Version 1.43053 Build 635768276
I: Identity: C3:06:3D:25:7F:73 (random)
I: HCI: version 5.4 (0x0d) revision 0x10b7, manufacturer 0x0059
I: LMP: version 5.4 (0x0d) subver 0x10b7
Bluetooth initialized
LLPM mode enabled
Choose device role - type c (central) or p (peripheral): p
Slave role. Starting advertising
Choose device role - type c (central) or p (peripheral):
Peripheral. Starting advertising
Advertising successfully started
Connection event reports enabled
Filter not match. Address: 1d:18:b1:84:fd:05 (random) connectable: 0
Filter not match. Address: 00:92:3f:a6:3f:48 (random) connectable: 0
Filter not match. Address: 02:ec:f9:bb:ec:27 (random) connectable: 0
Filter not match. Address: 3e:21:91:91:52:82 (random) connectable: 0
Filter not match. Address: 08:c6:a4:e0:72:e9 (random) connectable: 0
Filter not match. Address: 13:04:eb:f1:0b:46 (random) connectable: 0
Filter not match. Address: cb:01:1a:2d:6e:ae (random) connectable: 1
Filter not match. Address: 5c:f2:70:c2:3f:9f (random) connectable: 1
W: opcode 0x200a status 0x0d
Connected as peripheral
Conn. interval is 80 units (1.25 ms/unit)
Conn. interval is 3329 units (1.25 ms/unit)
W: opcode 0x2032 status 0x3a
E: Failed LE Set PHY (-5)
Security changed: level 2, err: 0
Service discovery completed
Press any key to start measuring transmission latency
Transmission Latency: 80917 (us), CRC mismatches: 0
Transmission Latency: 80841 (us), CRC mismatches: 0
Transmission Latency: 80749 (us), CRC mismatches: 0
Transmission Latency: 80673 (us), CRC mismatches: 0
Transmission Latency: 80596 (us), CRC mismatches: 0
Transmission Latency: 80505 (us), CRC mismatches: 0
Transmission Latency: 80429 (us), CRC mismatches: 0
Transmission Latency: 80337 (us), CRC mismatches: 0
Transmission Latency: 80261 (us), CRC mismatches: 0
Transmission Latency: 80184 (us), CRC mismatches: 0
Transmission Latency: 80093 (us), CRC mismatches: 0
Transmission Latency: 80017 (us), CRC mismatches: 0
Transmission Latency: 79940 (us), CRC mismatches: 0
Transmission Latency: 79849 (us), CRC mismatches: 0
Connection interval updated: LLPM (1 ms)
Transmission Latency: 81604 (us), CRC mismatches: 0
Transmission Latency: 30181 (us), CRC mismatches: 0
Transmission Latency: 1098 (us), CRC mismatches: 0
Transmission Latency: 1129 (us), CRC mismatches: 0
Transmission Latency: 1037 (us), CRC mismatches: 0
Transmission Latency: 930 (us), CRC mismatches: 0
Transmission Latency: 1083 (us), CRC mismatches: 0
Transmission Latency: 1312 (us), CRC mismatches: 0
Transmission Latency: 900 (us), CRC mismatches: 0
Transmission Latency: 1007 (us), CRC mismatches: 0
Transmission Latency: 1052 (us), CRC mismatches: 0
Transmission Latency: 1083 (us), CRC mismatches: 0
Transmission Latency: 1358 (us), CRC mismatches: 0
Transmission Latency: 915 (us), CRC mismatches: 0
Transmission Latency: 1007 (us), CRC mismatches: 0
Transmission Latency: 1052 (us), CRC mismatches: 0
Transmission Latency: 1098 (us), CRC mismatches: 0
Transmission Latency: 1296 (us), CRC mismatches: 0
Transmission Latency: 900 (us), CRC mismatches: 0
Transmission Latency: 1007 (us), CRC mismatches: 0
Connection interval updated: 7.5 ms
Transmission Latency: 1052 (us), CRC mismatches: 0
Transmission Latency: 7247 (us), CRC mismatches: 0
Transmission Latency: 5950 (us), CRC mismatches: 0
Transmission Latency: 4867 (us), CRC mismatches: 0
Transmission Latency: 7293 (us), CRC mismatches: 0
Transmission Latency: 5996 (us), CRC mismatches: 0
Transmission Latency: 4913 (us), CRC mismatches: 0
Transmission Latency: 7385 (us), CRC mismatches: 0
Transmission Latency: 6088 (us), CRC mismatches: 0
Transmission Latency: 5004 (us), CRC mismatches: 0


Dependencies
Expand Down
48 changes: 30 additions & 18 deletions samples/bluetooth/llpm/src/main.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -27,9 +27,9 @@

#define DEVICE_NAME CONFIG_BT_DEVICE_NAME
#define DEVICE_NAME_LEN (sizeof(DEVICE_NAME) - 1)
#define INTERVAL_MIN 0x6 /* 6 units, 7.5 ms */
#define INTERVAL_MAX 0x6 /* 6 units, 7.5 ms */
#define INTERVAL_LLPM 0x0D01 /* Proprietary 1 ms */
#define INTERVAL_MIN 0x6 /* 6 units, 7.5 ms */
#define INTERVAL_MIN_US 7500 /* 7.5 ms */
#define INTERVAL_LLPM 0x0D01 /* Proprietary 1 ms */
#define INTERVAL_LLPM_US 1000


Expand All @@ -39,7 +39,7 @@ static struct bt_conn *default_conn;
static struct bt_latency latency;
static struct bt_latency_client latency_client;
static struct bt_le_conn_param *conn_param =
BT_LE_CONN_PARAM(INTERVAL_MIN, INTERVAL_MAX, 0, 400);
BT_LE_CONN_PARAM(INTERVAL_LLPM, INTERVAL_LLPM, 0, 400);
static struct bt_conn_info conn_info = {0};

static const struct bt_data ad[] = {
Expand Down Expand Up @@ -230,6 +230,9 @@ static void le_param_updated(struct bt_conn *conn, uint16_t interval,
{
if (interval == INTERVAL_LLPM) {
printk("Connection interval updated: LLPM (1 ms)\n");
} else {
__ASSERT_NO_MSG(interval == INTERVAL_MIN);
printk("Connection interval updated: 7.5 ms\n");
}
}

Expand Down Expand Up @@ -259,7 +262,7 @@ static int enable_llpm_mode(void)
return 0;
}

static int enable_llpm_short_connection_interval(void)
static int vs_change_connection_interval(uint16_t interval_us)
{
int err;
struct net_buf *buf;
Expand All @@ -283,7 +286,7 @@ static int enable_llpm_short_connection_interval(void)

cmd_conn_update = net_buf_add(buf, sizeof(*cmd_conn_update));
cmd_conn_update->connection_handle = conn_handle;
cmd_conn_update->conn_interval_us = INTERVAL_LLPM_US;
cmd_conn_update->conn_interval_us = interval_us;
cmd_conn_update->conn_latency = 0;
cmd_conn_update->supervision_timeout = 300;

Expand Down Expand Up @@ -367,25 +370,13 @@ static const struct bt_latency_client_cb latency_client_cb = {
static void test_run(void)
{
int err;

if (!test_ready) {
/* disconnected while blocking inside _getchar() */
return;
}

test_ready = false;

/* Switch to LLPM short connection interval */
if (conn_info.role == BT_CONN_ROLE_CENTRAL) {
printk("Press any key to set LLPM short connection interval (1 ms)\n");
console_getchar();

if (enable_llpm_short_connection_interval()) {
printk("Enable LLPM short connection interval failed\n");
return;
}
}

printk("Press any key to start measuring transmission latency\n");
console_getchar();

Expand All @@ -409,6 +400,27 @@ static void test_run(void)
}

memset(&llpm_latency, 0, sizeof(llpm_latency));
if (conn_info.role == BT_CONN_ROLE_CENTRAL) {
static int counter;
static uint16_t interval_us = INTERVAL_LLPM_US;

counter++;
/* Arbitrarily chosen number of measurments
* to do before switching interval
*/
if (counter == 20) {
counter = 0;
if (interval_us == INTERVAL_LLPM_US) {
interval_us = INTERVAL_MIN_US;
} else {
interval_us = INTERVAL_LLPM_US;
}
if (vs_change_connection_interval(interval_us)) {
printk("Enable LLPM short connection interval failed\n");
return;
}
}
}
}
}

Expand Down
1 change: 1 addition & 0 deletions subsys/bluetooth/controller/Kconfig
View file
Original file line number Diff line number Diff line change
Expand Up @@ -103,6 +103,7 @@ config SYSTEM_WORKQUEUE_STACK_SIZE
config BT_CTLR_SDC_LLPM
bool "Enable Low Latency Packet Mode support"
depends on SOC_SERIES_NRF52X
select BT_CONN_PARAM_ANY
help
Low Latency Packet Mode (LLPM) is a Nordic proprietary addition
which lets the application use connection intervals down to 1 ms.
Expand Down

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