Questions about CC3200 Simplelink

Hi Pedro,

To answer your questions:

- You can get the subnet mask using the below code:

    _u8 len = sizeof(SlNetCfgIpV4Args_t);
    _u8 dhcpIsOn = 0; // this flag is meaningless on AP/P2P go.
    SlNetCfgIpV4Args_t ipV4 = {0};

    sl_NetCfgGet(SL_IPV4_STA_P2P_CL_GET_INFO,&dhcpIsOn,&len,(_u8 *)&ipV4);

    UART_PRINT("IP %d.%d.%d.%d MASK %d.%d.%d.%d GW %d.%d.%d.%d DNS %d.%d.%d.%d\n\r",
            SL_IPV4_BYTE(ipV4.ipV4,3),SL_IPV4_BYTE(ipV4.ipV4,2),SL_IPV4_BYTE(ipV4.ipV4,1),SL_IPV4_BYTE(ipV4.ipV4,0),
            SL_IPV4_BYTE(ipV4.ipV4Mask,3),SL_IPV4_BYTE(ipV4.ipV4Mask,2),SL_IPV4_BYTE(ipV4.ipV4Mask,1),SL_IPV4_BYTE(ipV4.ipV4Mask,0),
            SL_IPV4_BYTE(ipV4.ipV4Gateway,3),SL_IPV4_BYTE(ipV4.ipV4Gateway,2),SL_IPV4_BYTE(ipV4.ipV4Gateway,1),SL_IPV4_BYTE(ipV4.ipV4Gateway,0),
            SL_IPV4_BYTE(ipV4.ipV4DnsServer,3),SL_IPV4_BYTE(ipV4.ipV4DnsServer,2),SL_IPV4_BYTE(ipV4.ipV4DnsServer,1),SL_IPV4_BYTE(ipV4.ipV4DnsServer,0));

- Yes, that is the range for RSSI values.

- When the CC3200 is already connected to an AP,  you can use the API sl_WlanRxStatGet to get the RSSI values of the connected AP. .

- You cannot access the HTTP server by hostname when the device starts in station mode. You can only access it using the IP address.

- You can check sl_Recv to see when the remote device closes the socket. For non blocking sl_Recv, a return code of -11 would return for EAGAIN. If the socket is closed by the remote device, 0 would be returned.

Regards,
Raghavendra

Hello Raghavendra, thanks (again) for your help!

- About subnet mask, my bad! Missing a deep read on NWP document... I was looking for mask in "SimpleLinkNetAppEventHandler", but that's ok with a function!

- About "sl_WlanRxStatGet" for the actual connection, it's ok too. In fact, as NWP said, there are 3 commands to issue... The ideia is to make my HTML page "polling" the rssi information, but I'm afraid it can decrease the WiFi performance... Maybe I can call the three functions each 4 seconds...

Anyway, if I'm still connected to an AP, can I start a scan and collect information about others APs?

- About "sl_Recv", the problem with "0" is that there's no sequence for data transfer (in other words, the server can send "n" bytes to client and get no byte as response; the server can send "n" bytes and get "n" bytes from client; the client can send "n" bytes to server...). If we had a command to read socket status, it could be use before a "sl_Recv"/"sl_Send" commands...

Thanks in advance!

Hi Pedro,

- You can do a scan when the CC3200 is in connected mode.

- The application should check the status for remote close in a non-blocking sl_Recv for the different sequence that you have defined above. As this gives the correct indication of a remote device closing the socket.
A no-response will make the sl_Recv return -11, and for rest of the case it will return "n". There is no API to check the status of the socket.

Regards,
Raghavendra

Hello Raghavendra!

I've tried to issue a new scan when I'm already connected and didn't work... I'm using "WlanScan" function from "scan_policy" example and it stops in first "sl_WlanPolicySet" command ("make sure the connection policy is not set"). When I'm not connected to an AP, the "WlanScan" function works fine. BTW, about rssi from "sl_WlanGetNetworkList" that I asked before, I think that's not the real range... I've got the signal from a neighbor AP with -97 dBm value... so I think the range is from 0 dBm (excelent signal) to -100 dBm (poor signal).

About TCP server socket (non blocking), take a look in this piece of my state machine:

// -------------------------------------------------------------------
case SR_LISTENING:
    // ** CLIENT SENT SOMETHING? **
    iStatus = sl_Recv(serverSockCli, g_InTcpBuffer, BUF_SIZE, 0);
    if( iStatus < 0 ){
        // error!
        lastError = RECV_ERROR;
        posTcpServer = SR_ERROR;
    }
    else if( iStatus > 0 ){
        // yes
        #ifdef _USE_MY_UART_
        // Send it to UART...
        int i;
        for(i=0;i<iStatus;i++)
            UARTA1put_uc( g_InTcpBuffer[i] );
        #endif
    }

    // ** SEND SOMETHING TO CLIENT? **
    #ifdef _USE_MY_UART_
    if( rxFlagUARTA1 ){
        // yes
        rxFlagUARTA1 = 0;

        iStatus = sl_Send(serverSockCli, bufferUARTA1_RX, countBufferUARTA1, 0);
        if( iStatus < 0 ){
            // error!
            lastError = SEND_ERROR;
            posTcpServer = SR_ERROR;
        }
    }
    #endif
break;
// -------------------------------------------------------------------

In other words, I'm listening both UART and the client already connected to "serverSockCli" socket. The point is, when the client disconnect, I'm still stuck in this state. I was hopping a negative value from "sl_Recv" (SL_EAGAIN), but this isn't happening...

Thanks again!

Hi Pedro,

I am able to get the scan working when in connected mode. Please use the standard getting_started_with_wlan_station example. And add the wlanScan function as shown below

#define WLAN_SCAN_COUNT 20
Sl_WlanNetworkEntry_t netEntries[WLAN_SCAN_COUNT ];

void wlanScan(void)
{
    unsigned short ucIndex;
    unsigned char ucpolicyOpt;
    long lRetVal = -1;

    union
    {
        unsigned char ucPolicy[4];
        unsigned int uiPolicyLen;
    }policyVal;

    //
	// make sure the connection policy is not set (so no scan is run in the
	// background)
	//
	ucpolicyOpt = SL_CONNECTION_POLICY(0, 0, 0, 0,0);
	lRetVal = sl_WlanPolicySet(SL_POLICY_CONNECTION , ucpolicyOpt, NULL, 0);
	if(lRetVal != 0)
	{
		GPIO_IF_LedOn(MCU_EXECUTE_FAIL_IND);
		UART_PRINT("Unable to clear the Connection Policy\n\r");
		return;
	}

	//
	// enable scan
	//
	ucpolicyOpt = SL_SCAN_POLICY(1);
	//
	// set scan cycle to 10 seconds
	//
	policyVal.uiPolicyLen = 10;
	//
	// set scan policy - this starts the scan
	//
	lRetVal = sl_WlanPolicySet(SL_POLICY_SCAN , ucpolicyOpt,
							   (unsigned char*)(policyVal.ucPolicy), sizeof(policyVal));
	if(lRetVal!=0)
	{
		GPIO_IF_LedOn(MCU_EXECUTE_FAIL_IND);
		UART_PRINT("Unable to set the Scan Policy\n\r");
		return;
	}
	MAP_UtilsDelay(8000000);
	//
	// get scan results - all 20 entries in one transaction
	//
	ucIndex = 0;
	//
	// retVal indicates the valid number of entries
	// The scan results are occupied in netEntries[]
	//
	lRetVal = sl_WlanGetNetworkList(ucIndex, (unsigned char)WLAN_SCAN_COUNT,
									&netEntries[ucIndex]);
	if(lRetVal==0)
	{
		GPIO_IF_LedOn(MCU_EXECUTE_FAIL_IND);
		UART_PRINT("Unable to retreive the network list\n\r");
		return;
	}
	/* put a break point here and check netEntries[] value for scan ssid list */
	//
	// get scan results - 4 transactions of 5 entries
	//
	ucIndex = 0;
	memset(netEntries, 0, sizeof(netEntries));

    lRetVal = sl_WlanGetNetworkList(ucIndex,
									(unsigned char)WLAN_SCAN_COUNT,
									&netEntries[ucIndex]);

    Report("\n\r Scan list\n\r");
    Report("======================\n\r");

    for(ucIndex = 0; ucIndex < WLAN_SCAN_COUNT; ucIndex++)
    {
    	Report(" %s \n\r", netEntries[ucIndex].ssid);
    }

    Report("Scan complete\n\r");

    /* put a break point here and check netEntries[] value for scan ssid list */
	//
	// disable scan
	//
	ucpolicyOpt = SL_SCAN_POLICY(0);
	lRetVal = sl_WlanPolicySet(SL_POLICY_SCAN , ucpolicyOpt, NULL, 0);
	if(lRetVal != 0)
	{
		GPIO_IF_LedOn(MCU_EXECUTE_FAIL_IND);
		UART_PRINT("Unable to Clear the Scan Policy\n\r");
		return;
	}

	GPIO_IF_LedOn(MCU_EXECUTE_SUCCESS_IND);
	UART_PRINT("SUCCESS\n\r");
}

void WlanStationMode( void *pvParameters )
{

    long lRetVal = -1;

    InitializeAppVariables();

    //
    // Following function configure the device to default state by cleaning
    // the persistent settings stored in NVMEM (viz. connection profiles &
    // policies, power policy etc)
    //
    // Applications may choose to skip this step if the developer is sure
    // that the device is in its default state at start of applicaton
    //
    // Note that all profiles and persistent settings that were done on the
    // device will be lost
    //
    lRetVal = ConfigureSimpleLinkToDefaultState();
    if(lRetVal < 0)
    {
        if (DEVICE_NOT_IN_STATION_MODE == lRetVal)
        {
            UART_PRINT("Failed to configure the device in its default state\n\r");
        }

        LOOP_FOREVER();
    }

    UART_PRINT("Device is configured in default state \n\r");

    //
    // Assumption is that the device is configured in station mode already
    // and it is in its default state
    //
    lRetVal = sl_Start(0, 0, 0);
    if (lRetVal < 0 || ROLE_STA != lRetVal)
    {
        UART_PRINT("Failed to start the device \n\r");
        LOOP_FOREVER();
    }

    UART_PRINT("Device started as STATION \n\r");

    //
    //Connecting to WLAN AP
    //
    lRetVal = WlanConnect();
    if(lRetVal < 0)
    {
        UART_PRINT("Failed to establish connection w/ an AP \n\r");
        LOOP_FOREVER();
    }

    UART_PRINT("Connection established w/ AP and IP is aquired \n\r");
    UART_PRINT("Pinging...! \n\r");

    wlanScan();
    .
    .
}

Regarding the TCP server, we will check it and get back to you.

Regards,
Raghavendra