Logging
The SDT features a logging mechanism allowing to record the devices interaction throughout the day. Data is stored in the filesystem and can be accessed over the air. A gateway can access this data. A reference implementation is provided and described in the Gateway section of this document.
GATT interface
The logging service is as follows:
| Type | Access | UUID | Description |
|---|---|---|---|
| Service | N.A. | 3112fb86-86c7-11ea-bc55-0242ac130003 | Logging service |
| Property | Read | 3112fb86-86c7-11ea-bc55-000000000003 | ZONE_X_LOG |
| Property | Write | 3112fb86-86c7-11ea-bc55-000000000004 | ZONE selection |
| Property | Write | 3112fb86-86c7-11ea-bc55-000000000005 | PTR_CONFIG |
| Property | Write | 3112fb86-86c7-11ea-bc55-000000000006 | FLD_RESET |
Zone enumeration:
| Name | Value |
|---|---|
| Danger | 0 |
| Warning | 1 |
| Coarse | 2 |
| Limit | 3 |
In order to read the logs for a specific zone, the gateway should issue a write to the ZONE selection characteristic then a read to the ZONE_X_LOG characteristic. The SDT will then send as many entries as there are in the log file for that specific zone. The transmission will be terminated by the transmission of a packet of length zero. In the case that the transmission does not complete, the gateway can reinitialize the transmission by writing zero in the PTR_CONFIG characteristic. A write in the FLD_RESET characteristic will clear the log file for the selected zone.
Logging format
The logging format is highly flexible as it is implemented through a set of macros in the application leaving freedom for the end application to modify it at will. For each event , the reference implementation logs the using the format described in the following table.
Byte |
Item |
Detail |
Data Type |
Byte Order |
|---|---|---|---|---|
0 |
Log Entry Start |
0x7C “|” |
ASCII char/ uint8_t |
|
1 |
SDT Type |
0 – Wearable
X – Reserved
|
||
2 |
SDT ID |
uint32_t |
LSB |
|
3 |
||||
4 |
||||
5 |
MSB |
|||
6 |
Event Year |
e.g.2020 |
uint16_t |
LSB |
7 |
MSB |
|||
8 |
Event Month |
e.g. 4 for April |
uint8_t |
|
9 |
Event Day |
25 |
uint8_t |
|
10 |
Event Hour |
13 |
uint8_t |
|
11 |
Event Minute |
37 |
uint8_t |
|
12 |
Event Seconds |
37 |
uint8_t |
|
13 |
Zone |
0 - Danger
1 – Warning
2 – Coarse
3 – Limit
|
uint8_t |
|
14 |
Remote SDT Type |
0 – Wearable
X – Reserved
|
||
15 |
Remote SDT ID |
uint32_t |
LSB |
|
16 |
||||
17 |
||||
18 |
MSB |
|||
19 |
Local Battery % |
uint8_t |