CC3220S-LAUNCHXL: STA mode automatic re-connect

Hi Michael,

Initially I put the device in AP mode, then open the local page where I have a simple form of sending credentials. When user submits the form I do http post to /api/1/wlan/profile_add as described in Section 8.4.4 of Programmer's Guide. I also send the credentials by regular http post and record those in the device under "ap_username_in" and "ap_password_in" variables. Then I use sl_WlanProfileAdd(). Below is my usage:

SecParams.Type = SL_WLAN_SEC_TYPE_WPA_WPA2;
SecParams.Key = (signed char *)ap_password_in;
SecParams.KeyLen = strlen((const char *)SecParams.Key);
index = sl_WlanProfileAdd((signed char*)ap_username_in, strlen((const char*)ap_username_in), MacAddr, &SecParams, NULL, 7, 0);
UART_PRINT("[Link Local Task] STA profile added with status %d \n\r", index);

The profile is being added successfully and the device is able to connect when it is reset. The problem is only when the connection is suddenly interrupted on router side. In that case the device doesn't re-connect. I dp policy settings when device starts:

// Set auto connect policy
status = sl_WlanPolicySet(SL_WLAN_POLICY_CONNECTION, SL_WLAN_CONNECTION_POLICY(1, 0, 0, 0), NULL, 0);
if (status < 0) {
UART_PRINT("[setSTAmode] Error %d Failed to set connection policy to auto connect\n\r", status);
while (1);
}

// Enable DHCP client
status = sl_NetCfgSet(SL_NETCFG_IPV4_STA_ADDR_MODE, SL_NETCFG_ADDR_DHCP, 0, 0);
if (status < 0) {
UART_PRINT("[setSTAmode] Error %d Could not enable DHCP client\n\r", status);
while (1);
}

I double check the existence of the profile in SimpleLinkWlanEventHandler as I posted. It truly is not the best practice what I have in the handler, thanks for advice.

Can you help understand why the re-connection doesn't happen if the profile exists? Maybe there is some sort of timeout? Where are the settings for the re-connection timeout located, I wasn't able to find?

Thanks,
David

Hi David,

Looking through your code, the main thing that jumps out is how you pass in MacAddr in the sl_WlanProfileAdd() call. The MacAddr is the BSSID of the AP, which allows you to specify a specific AP to connect to in case there are multiple APs broadcasting on the same SSID in the area and you wanted to connect to a specific one.

What happens if you the same thing but pass in 0 instead of MacAddr?

Regards,
Michael

Hi Michael,

I used the following for MacAddr:
_u8 MacAddr[] = {0xAA,0xBB,0xCC,0xDD,0xEE,0xFF};

In my testing the router SSID name is unique.

Do you think the above could cause the problem with re-connection?

Thanks,
David

Hi David,

If the MAC address provided does not match the BSSID of your AP, your profile shouldn't be able to connect. I'm not sure how your device managed to connect in the first place if you had a wrong BSSID. Please change MacAddr to 0 in your sl_WlanProfileAdd() call and see if that helps.

Regards,
Michael

Hi Michael,

Thank you for your help. I tried your suggestion and WLAN connection works. But it looks like my problem has been completely different. And here it goes..

FYI, I am using shadow_sample application as base. On the top of the example I basically added link local features to be able to pass the SSID credentials from a mobile phone to the CC3220 device. Again, the re-connection worked perfectly when I unplugged the CC3220 device and then plugged it back in again. CC3220 was able to load the profile and connect to my network. The problem occurred when I suddenly re-started the router. Here's a log depicting the process - green section is for the period when the device was connected, red section is for the period when the router was re-started:

==========================================================

On Device: window state false
Update Shadow: {"state":{"reported":{"temperature":25.500000,"windowOpen":false}}, "clientToken":"mydevice_unique-0"}

==========================================================

Update Accepted !!
Delta - Window state changed to 1

==========================================================

On Device: window state true
Update Shadow: {"state":{"reported":{"temperature":26.000000,"windowOpen":true}}, "clientToken":"mydevice_unique-1"}

==========================================================

Update Accepted !!

==========================================================

On Device: window state true
Update Shadow: {"state":{"reported":{"temperature":26.500000,"windowOpen":true}}, "clientToken":"mydevice_unique-2"}

==========================================================

Update Accepted !!

==========================================================

On Device: window state true
Update Shadow: {"state":{"reported":{"temperature":27.000000,"windowOpen":true}}, "clientToken":"mydevice_unique-3"}

==========================================================

Update Accepted !!

==========================================================

On Device: window state true
Update Shadow: {"state":{"reported":{"temperature":27.500000,"windowOpen":true}}, "clientToken":"mydevice_unique-4"}

==========================================================

Update Accepted !!

==========================================================

On Device: window state true
Update Shadow: {"state":{"reported":{"temperature":28.000000,"windowOpen":true}}, "clientToken":"mydevice_unique-5"}

==========================================================

==========================================================

On Device: window state true
Update Shadow: {"state":{"reported":{"temperature":28.500000,"windowOpen":true}}, "clientToken":"mydevice_unique-6"}

==========================================================

==========================================================

On Device: window state true
Update Shadow: {"state":{"reported":{"temperature":29.000000,"windowOpen":true}}, "clientToken":"mydevice_unique-7"}

==========================================================

Update Timeout--

==========================================================

On Device: window state true
Update Shadow: {"state":{"reported":{"temperature":29.500000,"windowOpen":true}}, "clientToken":"mydevice_unique-8"}

==========================================================

[SimpleLinkWlanEventHandler] WLAN has disconnected!!!
Update Timeout--

==========================================================

On Device: window state true
Update Shadow: {"state":{"reported":{"temperature":30.000000,"windowOpen":true}}, "clientToken":"mydevice_unique-9"}

==========================================================

Update Timeout--

==========================================================

On Device: window state true
Update Shadow: {"state":{"reported":{"temperature":30.500000,"windowOpen":true}}, "clientToken":"mydevice_unique-10"}

==========================================================

Update Timeout--
Update Timeout--
Update Timeout--
[SimpleLinkWlanEventHandler] WLAN is now connected!!!

==========================================================

On Device: window state true
Update Shadow: {"state":{"reported":{"temperature":31.000000,"windowOpen":true}}, "clientToken":"mydevice_unique-11"}

==========================================================

ERROR: runAWSClient L#212 An error occurred in the loop -26
Disconnecting
ERROR: runAWSClient L#219 Disconnect error -13

The above message is the last one, nothing happens after this.

HOWEVER, there is one small green line in the red text that I was missing. It says: [SimpleLinkWlanEventHandler] WLAN is now connected!!!

So WLAN actually connects when the router turns back on after the restart but the runAWSClient is not able to reconnect. How should I solve this? Restarting the runAWSClient from SimpleLinkWlanEventHandler function is not advised, correct? What would be the recommended method?

Thanks a lot for your advice!

David

===========================================

Hi Michael,

Thanks, it worked.

Thanks,
David