AT+S.SCAN problem

sandro · ‎2016-03-08

Posted on March 08, 2016 at 15:00

Hi,

I performed a session of test with this spwf01 module in station mode with a router wifi.

I saw a problem that it accours sometimes during a scanning for find

wifi network.

I sent a command to the module:

AT+S.SCAN

The module answer

1: BSS C4:EA:1D:B1:CA:43 CHAN: 01 RSSI: -83 SSID: 'Telecom-29755459' CAPS: 0411 WPA WPA2 WPS

2: BSS D0:D4:12:A6:C0:3B CHAN: 01 RSSI: -86 SSID: 'Telecom-44482613' CAPS: 0411 WPA WPA2 WPS

3: BSS 98:E7:F5:49:55:67 CHAN: 01 RSSI: -84 SSID: 'WebPocket-5567' CAPS: 0411 WPA2 WPS

4: BSS 10:13:EE:07:5F:B5 CHAN: 06 RSSI: -89 SSID: 'Optima Italia' CAPS: 0411 WPA WPA2

5: BSS C4:6E:1F:F4:DB:62 CHAN: 07 RSSI: -48 SSID: 'WebPocket-1558' CAPS: 0431 WPA2 WPS

6: BSS 54:B8:0A:13:8D:10 CHAN: 11 RSSI: -80 SSID: 'abcpp' CAPS: 0431 WPA WPA2 WPS

I connected the module at the sixth Network and selected a bad password that saved in the memory of the device spwf01.

I selected a correct private mode

AT+S.SCFG=wifi_priv_mode,2

response:OK

AT&w

response:OK

I turned on again the module and after that appeared these messages :

+WIND:1:Poweron (150410-c2e37a3-SPWF01S)

+WIND:3:Watchdog Running

+WIND:0:Console active

+WIND:32:WiFi Hardware Started

+WIND:21:WiFi Scanning

+WIND:35:WiFi Scan Complete (0x0)

+WIND:18:WiFi Join:54:B8:0A:13:8D800

+WIND:21:WiFi Scanning

+WIND:35:WiFi Scan Complete (0x0)

+WIND:19:WiFi Join:54:B8:0A:138D:10

AT+S.SCAN ( I send a new command AT+S.SCAN but the module answer )

ERROR: Wait for Hardware Busy

The only mode for resolve this error is change the private mode to zero

AT+S.SCFG=wifi_priv_mode,0

response:OK

AT&w

response:OK

and restart the module.

Now if send a scan request the module return the wifi network list correctly.

why This happens sometimes?

what is the reason?

Gerardo GALLUCCI · ‎2016-03-08

Posted on March 08, 2016 at 20:47

Ciao Sandro,

first of all, please update to FW3.5.

About your questions:

1 - ''ERROR: Wait for Hardware Busy'' means the module is performing a Join (Wind:18). Try again later;

2 - module is repeating scan/complete/join since priv_mode is wrong. When authentication fails, module automatically comes back to scan state, and loop scan/complete/join start again. Please note that ''Join'' does not generate traffic over the air. If you use a sniffer, you'll find authentication frames after the Join Wind, with a ''bad'' reply from the AP. After a few seconds, a new scan is scheduled.

3 - complete sequence is scan/scan complete/join/authentication (request and reply)/association (request and reply)/DHCP HandShake (discover, offer, request and ack)/WiFi UP Wind

Ciao

j