bt_gatt_chrc_update_by_ref()

Description

This function is designed to update GATT server characteristic values and dispatch notifications or indications when enabled. It uses the user-defined reference to identify the characteristic and is best suited for handling string and custom data types.

Syntax

bt_gatt_chrc_update_by_ref(user_ref, data[], data_length);

Parameters

Variable	Input

Variable	Input
`user_ref`	User-defined reference from chracteristic creation. Available range 1-240.
`data[]`	Data buffer to update the characteristic value.
`data_length`	Length of the data to be updated. Maximum data length value is 200 bytes.

Returns

Return value	Return explanation
SCRIPT_OPERATION_SUCCESS	Successfully updated the characteristic value.
SCRIPT_OPERATION_FAILED	Failed to update the characteristic value.
SCRIPT_NO_ACCESS	Bluetooth GATT server is not initialized.
SCRIPT_PARAM_INVALID	Possible reasons: Characteristic was not found in the GATT server. Data did not fit in the characteristic value buffer.

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[UUID_LENGTH_128_BIT] = [0x05, 0x12, 0x96, 0x99, 0x00, 0x00, 0x10, 0x00, 0x80, 0x00, 0x00, 0x80, 0x5F, 0x9B, 0x34, 0xFB];
new chrc_ref = 3;
new chrc_data[40];

main()
{   
    bt_init();
    bt_gatt_server_init();
    bt_gatt_service_create(service_uuid);
    bt_gatt_chrc_create(chrc_uuid, GATT_CHRC_PROP_READ | GATT_CHRC_PROP_NOTIFY, sizeof(chrc_data), chrc_ref);
    bt_gatt_server_start();
    
    for(;;)
    {
        Delay(10000);
        snprintf(chrc_data, sizeof(chrc_data), "Ticks:%d\r\nVCC:%d\r\n", get_val(Sensor_Ticks), get_val(SENSOR_VCC));
        bt_gatt_chrc_update_by_ref(chrc_ref, chrc_data[], strlen(chrc_data));
    }
}