bt_gatt_server_receive()

Description

Function to receive data from the GATT client. Characteristic UUID and user reference are used for identification. Data can be read only once.

Syntax

bt_gatt_server_receive(data[]);

Parameters

Variable	Input

Variable	Input
`data[]`	Data buffer where the newly written characteristic value resides. Refer below for the data structure. The data header is specified to be 18 bytes, meaning that the buffer size needs to be a minimum of 19 bytes to successfully read a single data byte. The maximum allowable data size is 220 bytes.

Returns

Return value	Return explanation
SCRIPT_OPERATION_FAILED	Invalid data buffer.
SCRIPT_NO_ACCESS	Bluetooth GATT server is not initialized.
Data length	In case of success, function will return the number of bytes received in the buffer.

Data will follow this format:

Example 1 (No user reference was assigned):

GATT server callback data: 00 02 6E 40 00 03 B5 A3 F3 93 E0 A9 E5 0E 24 DC CA 9E 00 10

- User-defined reference

- UUID Type (0x00 - 16 bit UUID, 0x01 - 32 bit UUID, 0x02 - 128 bit UUID)

- UUID

- Data

Example 2 (User reference was assigned) :

GATT server callback data: 05 02 6E 40 00 04 B5 A3 F3 93 E0 A9 E5 0E 24 DC CA 9E 74 65 73 74

- User-defined reference

- UUID Type (0x00 - 16 bit UUID, 0x01 - 32 bit UUID, 0x02 - 128 bit UUID)

- UUID

- Data

Function call example

#include <io>
#include <read>
#include <float>
#include <string>
#include <core>
#include <write>
#include <define>
#include <socket>
#include <bluetooth>

new service_uuid[UUID_LENGTH_128_BIT] = [0x08, 0x07, 0x06, 0x05, 0x00, 0x00, 0x10, 0x00, 0x80, 0x00, 0x00, 0x80, 0x5F, 0x9B, 0x34, 0xFB];
new chrc_uuid_1[UUID_LENGTH_128_BIT] = [0x05, 0x12, 0x96, 0x99, 0x00, 0x00, 0x10, 0x00, 0x80, 0x00, 0x00, 0x80, 0x5F, 0x9B, 0x34, 0xFB];
new chrc_uuid_2[UUID_LENGTH_128_BIT] = [0x05, 0x12, 0x96, 0x99, 0x00, 0x00, 0x10, 0x00, 0x80, 0x00, 0x00, 0x80, 0x5F, 0x9B, 0x34, 0xFB];
new chrc_handle_2 = 5;
new gatt_rx_data[64];

forward public callback (event);

public callback (event)
{
    switch(event)
    {
        case BT_GATT_SERVER_RX:
        {
            new data_len = bt_gatt_server_receive(gatt_rx_data);
            
            if (gatt_rx_data[GATT_RX_HEADER_USER_REF_POS] == chrc_handle_2)
            {
                chrc_2_rx(data_len);
            }
        }
    }
    return 0;
}

chrc_2_rx(msg_len)
{
    /* Handle characteristic write code start */
    
    /* Handle characteristic write code end */
}

main()
{   
    bt_init();
    bt_gatt_server_init();
    bt_gatt_service_create(service_uuid);
    bt_gatt_chrc_create(chrc_uuid_1, GATT_CHRC_PROP_WRITE, 0, 0);
    bt_gatt_chrc_create(chrc_uuid_2, GATT_CHRC_PROP_WRITE, 0, chrc_handle_2);
    
    for(;;)
    {
        Delay(100);
    }
}