GATT Latency Service¶
The GATT Latency Service is a custom service containing a single writable characteristic. This characteristic can be used to calculate the round-trip time of a GATT Write operation.
Service UUID¶
The 128-bit service UUID is 67136E01-58DB-F39B-3446-FDDE58C0813A.
Characteristics¶
This service has one characteristic.
Latency Characteristic (67136E02-58DB-F39B-3446-FDDE58C0813A)¶
- Write
The server is waiting for a write request from the client, then it will automatically reply a write response back.
API documentation¶
include/bluetooth/services/latency.h
subsys/bluetooth/services/latency.c
-
group
bt_latency
API for the Bluetooth LE GATT Latency Service.
Defines
-
BT_UUID_LATENCY_VAL
¶ Latency Service UUID.
-
BT_UUID_LATENCY
¶
-
BT_UUID_LATENCY_CHAR
¶ UUID of the Latency Characteristic.
Functions
-
int
bt_latency_init
(struct bt_latency *latency, const struct bt_latency_cb *cb)¶ Initialize the GATT latency service.
- Parameters
[in] latency
: Latency service instance.[in] cb
: Callbacks.
- Return Value
0
: If the operation was successful. Otherwise, a negative error code is returned.(-EINVAL)
: Special error code used when the input parameters are invalid.(-EALREADY)
: Special error code used when the latency service has been initialed.
-
struct
bt_latency_cb
¶ - #include <latency.h>
Latency callback structure.
Public Members
-
void (*
latency_request
)(const void *buf, uint16_t len)¶ Latency received callback.
This function is called when a GATT write request has been received by the Latency characteristic.
It is optional for an application to handle the write request when measuring the latency.
- Parameters
[in] buf
: Latency data.[in] len
: Latency data length.
-
void (*
-
struct
bt_latency
¶ - #include <latency.h>
Latency structure.
-