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/*
*
* GattLib - GATT Library
*
* Copyright (C) 2016-2017 Olivier Martin <olivier@labapart.org>
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include "gattlib.h"
#define MIN(a,b) ((a)<(b)?(a):(b))
#define NUS_CHARACTERISTIC_TX_UUID "6e400002-b5a3-f393-e0a9-e50e24dcca9e"
#define NUS_CHARACTERISTIC_RX_UUID "6e400003-b5a3-f393-e0a9-e50e24dcca9e"
gatt_connection_t* m_connection;
void notification_cb(const uuid_t* uuid, const uint8_t* data, size_t data_length, void* user_data) {
int i;
for(i = 0; i < data_length; i++) {
printf("%c", data[i]);
}
}
static void usage(char *argv[]) {
printf("%s <device_address>\n", argv[0]);
}
void int_handler(int dummy) {
gattlib_disconnect(m_connection);
exit(0);
}
int main(int argc, char *argv[]) {
char input[256];
char* input_ptr;
int i, ret, total_length, length = 0;
uuid_t nus_characteristic_tx_uuid;
uuid_t nus_characteristic_rx_uuid;
if (argc != 2) {
usage(argv);
return 1;
}
m_connection = gattlib_connect(NULL, argv[1], BDADDR_LE_RANDOM, BT_SEC_LOW, 0, 0);
if (m_connection == NULL) {
fprintf(stderr, "Fail to connect to the bluetooth device.\n");
return 1;
}
// Convert characteristics to their respective UUIDs
ret = gattlib_string_to_uuid(NUS_CHARACTERISTIC_TX_UUID, strlen(NUS_CHARACTERISTIC_TX_UUID) + 1, &nus_characteristic_tx_uuid);
if (ret) {
fprintf(stderr, "Fail to convert characteristic TX to UUID.\n");
return 1;
}
ret = gattlib_string_to_uuid(NUS_CHARACTERISTIC_RX_UUID, strlen(NUS_CHARACTERISTIC_RX_UUID) + 1, &nus_characteristic_rx_uuid);
if (ret) {
fprintf(stderr, "Fail to convert characteristic RX to UUID.\n");
return 1;
}
// Look for handle for NUS_CHARACTERISTIC_TX_UUID
gattlib_characteristic_t* characteristics;
int characteristic_count;
ret = gattlib_discover_char(m_connection, &characteristics, &characteristic_count);
if (ret) {
fprintf(stderr, "Fail to discover characteristic.\n");
return 1;
}
uint16_t tx_handle = 0, rx_handle = 0;
for (i = 0; i < characteristic_count; i++) {
if (gattlib_uuid_cmp(&characteristics[i].uuid, &nus_characteristic_tx_uuid) == 0) {
tx_handle = characteristics[i].value_handle;
} else if (gattlib_uuid_cmp(&characteristics[i].uuid, &nus_characteristic_rx_uuid) == 0) {
rx_handle = characteristics[i].value_handle;
}
}
if (tx_handle == 0) {
fprintf(stderr, "Fail to find NUS TX characteristic.\n");
return 1;
} else if (rx_handle == 0) {
fprintf(stderr, "Fail to find NUS RX characteristic.\n");
return 1;
}
free(characteristics);
// Enable Status Notification
uint16_t enable_notification = 0x0001;
gattlib_write_char_by_handle(m_connection, rx_handle + 1, &enable_notification, sizeof(enable_notification));
// Register notification handler
gattlib_register_notification(m_connection, notification_cb, NULL);
// Register handler to catch Ctrl+C
signal(SIGINT, int_handler);
while(1) {
fgets(input, sizeof(input), stdin);
// NUS TX can only receive 20 bytes at a time
input_ptr = input;
for (total_length = strlen(input) + 1; total_length > 0; total_length -= length) {
length = MIN(total_length, 20);
ret = gattlib_write_char_by_handle(m_connection, tx_handle, input_ptr, length);
if (ret) {
fprintf(stderr, "Fail to send data to NUS TX characteristic.\n");
return 1;
}
input_ptr += length;
}
}
return 0;
}