I am using the XDK Bosch Sensor for a project which is programmed in C. The idea is that the XDK should be able to connect to another network. SSID and password are sent via MQTT. It is already possible to connect the XDK to a network at initalization. In order to receive a MQTT message, the function shown below is used which was partly adapted by Guides of Bosch. Whenever a MQTT message is received this function is executed.
The message I receive looks always as following: IP_Address/SSID/Password/ e.g. 192.155.125.146/TestSSID/TestPassword/
Already tested: The content is received correctly by the function itself
Already tested: CountNumberItemsPwd, CountNumberItemsSSID and CountNumberItemsIp count the number of characters of Pwd, SSID, and IP Address correctly
Using printf for the arrays arraySSID, arrayPW and arrayIp shows the correct content
Assumed Problem: The size of the char arrays, which are passed to the function connecting the XDK to a new network, seem to require to be sized properly. I tried to use oversized char arrays without success. Thus, I am currently trying to solve the problem with the help of alloc. Unfortunately, I cannot get it to work and cannot find what I am doing incorrectly with alloc.
#define COMMON_BUFFER_SIZE 255
char MQTT_BROKER_HOST[] = "192.111.111.111";
char message_received [COMMON_BUFFER_SIZE];
/**
* @brief Event handler for incoming publish MQTT data
*
* @param[in] publishData
* Event Data for publish
*/
static void HandleEventIncomingPublish(
MqttPublishData_T publishData)
{
char published_topic_buffer[COMMON_BUFFER_SIZE];
char published_data_buffer[COMMON_BUFFER_SIZE];
static int incoming_message_count = 0;
//storing topic and incoming data
strncpy(published_data_buffer, (const char *)publishData.payload, sizeof(published_data_buffer));
strncpy(published_topic_buffer, publishData.topic.start, sizeof(published_topic_buffer));
//If the message differs from the one received before, connect to new network
if (message_received != published_data_buffer)
{
//Store message in message_received
strcpy(message_sent, published_data_buffer);
//For While-Loop
int counterForArray = 0;
//For writing content into correct arrays
int BooleanForIP = 0;
int BooleanForPw = 0;
int BooleanForSSID = 0;
int CountCycles = 0; //For Array Access
//Counting of how many items IP Address, SSID and Password consist of
int CountNumberItemsIp = 0;
int CountNumberItemsPW = 0;
int CountNumberItemsSSID = 0;
//Buffer Arrays
char IP_new[20] = "";
char PW_new[50] = "";
char SSID_new[25] = "";
while (counterForArray < COMMON_BUFFER_SIZE)
{
//Check if IP Address has been successfully received
if (message_received[counterForArray] == '/' && BooleanForIP == 0 && BooleanForSSID == 0 && BooleanForPw == 0)
{
BooleanForIP = 1;
CountNumberItemsIp = CountCycles;
CountCycles = 0;
}
//Checking if SSID has been successfully received
else if (message_received[counterForArray] == '/' && BooleanForIP == 1 && BooleanForSSID == 0 && BooleanForPw == 0)
{
BooleanForSSID = 1;
CountNumberItemsSSID = CountCycles;
CountCycles = 0;
printf("Stage 2 reached \n");
}
//Checking if Password has been successfully received
else if (message_received[counterForArray] == '/' && BooleanForIP == 1 && BooleanForSSID == 1 && BooleanForPw == 0)
{
BooleanForPw = 1;
CountNumberItemsPW = CountCycles;
CountCycles = 0;
}
if (BooleanForIP == 0 && BooleanForPw == 0 && BooleanForSSID == 0)
{
IP_new[CountCycles] = message_received[counterForArray];
CountCycles = CountCycles + 1;
}
else if (BooleanForIP == 1 && BooleanForPw == 0 && BooleanForSSID == 0 && message_received[counterForArray] != '/')
{
SSID_new[CountCycles] = message_received[counterForArray];
CountCycles = CountCycles + 1;
}
else if (BooleanForIP == 1 && BooleanForPw == 0 && BooleanForSSID == 1 && message_received[counterForArray] != '/')
{
PW_new[CountCycles] = message_received[counterForArray];
CountCycles = CountCycles + 1;
}
counterForArray = counterForArray + 1;
}
//Dynamic memory
char *arraySSID;
arraySSID = (char*)calloc(CountNumberItemsSSID, sizeof(char));
char *arrayIP;
arrayIP = (char*)calloc(CountNumberItemsIp, sizeof(char));
char *arrayPW;
arrayPW = (char*)calloc(CountNumberItemsPW, sizeof(char));
//Copying content
int SSID = 0;
while (SSID <= CountNumberItemsSSID)
{
arraySSID[SSID] = SSID_new[SSID];
SSID = SSID + 1;
}
int PW = 0;
while (PW <= CountNumberItemsPW)
{
arrayPW[PW] = PW_new[PW];
PW = PW + 1;
}
int IP = 0;
while (IP <= CountNumberItemsIp)
{
arrayIP[IP] = IP_new[IP];
IP = IP + 1;
}
//Disconnecting from old Wifi
//Functions provided by Bosch
Retcode_T retStatusDisconnect = (Retcode_T) WlanConnect_Disconnect(0);
retcode_t DisconnectMQTT = Disconnect();
Retcode_T connect_rc3 = NetworkSetup(&arraySSID, &arrayPW);
if (connect_rc3 == RETCODE_OK)
{
printf("success \n");
}
else
{
Retcode_RaiseError(connect_rc3);
}
//Checking if content has been sent correctly
printf("%s :arraySSID \n",arraySSID);
printf("%s :arrayPW \n",arrayPW);
printf("%s :arrayIP \n",arrayIP);
printf("%s: SSID \n", SSID_new);
printf("%s: IP \n", IP_new);
printf("%s: PW \n", PW_new);
//Deallocate space
free(arraySSID);
free(arrayPW);
free(arrayIP);
}
//Print received message
printf("%s \n", message_received);
incoming_message_count++;
}
I am able to connect to a new network if I use following code in the function above instead of the arraySSID and arrayPwd even though arraySSID and arrayPwdshow the same content as testSSID and testPW when I print both on the console.
char testSSID[] = "TestSSID";
char testPW[] = "TestPwsd";
Retcode_T connect_rc3 = NetworkSetup(&testSSID, &testPW);
If I compare arraySSID, arrayPwd and the size of testSSIDand testPwd, a different size is allocated to them. arraySSID, arrayPwd are always of size 4.
For doing so, I used following code:
printf("%i \n", sizeof(arraySSID));
printf("%i \n", sizeof(testSSID));
printf("%d \n", sizeof(arrayPW));
printf("%d \n", sizeof(testPW));
The problem was indeed a pointer problem.. By using
Retcode_T connect_rc3 = NetworkSetup(arraySSID, arrayPW);
the function worked perfectly fine. I did not consider that arrayPW is already of type char *, so that &arraySSID is of type char **.
I also changed (IP <= CountNumberItemsIp) to (IP < CountNumberItemsIp).