blackbeard420/esp-idf
1
0
Fork 0
mirror of https://github.com/espressif/esp-idf synced 2025-03-10 17:49:10 -04:00
Code Issues Projects Releases Wiki Activity

docs:perfect 128-bit UUID description

Browse Source 
The previous description is not easy for the reader to understand, some changees have been made to perfect it.
Closes https://github.com/espressif/esp-idf/issues/5057
This commit is contained in:
liminyang 2020-06-17 11:58:41 +08:00
parent 5bf8ff55d3
commit 8364bca3f4
1 changed files with 3 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
examples/bluetooth/bluedroid/ble/gatt_client/tutorial/Gatt_Client_Example_Walkthrough.md
View File

@ -484,7 +484,8 @@ Where,
```c
#define REMOTE_SERVICE_UUID 0x00FF
```
There will be a detail to note if the UUID of the service application that the client is interested in is a 128-bit UUID, which is related to the little-endian storage mode of the processor architecture . The struct of UUID is defined as:
If UUID of the service application the user is interested in is 128-bit, then there is one note below for the user which is relevant with the little-endian storage mode of the processor architecture.
The struct of UUID is defined as:
```c
typedef struct {
@ -500,7 +501,7 @@ typedef struct {
} __attribute__((packed)) esp_bt_uuid_t;
```
In little-endian storage mode, you can define service UUID directly in the normal order if it's a 16-bit or a 32-bit UUID. However, if service UUID is a 128-bit UUID, there is a little difference. For example, if the UUID of the service application that the client is interested in is 12345678-a1b2-c3d4-e5f6-9fafd205e457, `REMOTE_SERVICE_UUID` should be defined as {0x57,0xE4,0x05,0xD2,0xAF,0x9F,0xF6,0xE5,0xD4,0xC3,0xB2,0xA1,0x78,0x56,0x34,0x12}.
Note: In little-endian storage mode, you can define service UUID directly in the normal order if it's a 16-bit or a 32-bit UUID, but if service UUID is 128-bit, there is minor difference. For example, if the UUID of the service application that the user is interested in is 12345678-a1b2-c3d4-e5f6-9fafd205e457, `REMOTE_SERVICE_UUID` should be defined as {0x57,0xE4,0x05,0xD2,0xAF,0x9F,0xF6,0xE5,0xD4,0xC3,0xB2,0xA1,0x78,0x56,0x34,0x12}.
The services are then discovered as follows: