MediaTek LinkIt™ Connect 7681 Developer's Guide
© 2015, 2016 MediaTek Inc.
Page 53 of 65
This document contains information that is proprietary to MediaTek Inc.
Unauthorized reproduction or disclosure of this information in whole or in part is strictly prohibited.
However, if there are issues with the connection they may be identified as follows:
•
if the state switches from
SM=1,
Sub=0
to
SM=0,
Sub=0
Smart Connection has failed,
possibly because the user did not click the button that fires
start API:
SartSmartConnection
in the Android app.
•
if the state switches from
SM=2, Sub=0
to
SM=0, Sub=0
the scan operation failed. Likely
reasons for this are:
o
the wireless AP with the stated SSID isn’t available.
o
the wireless AP information received from Smart Connection is not correct.
In the second case, you can use a network analyzer, such as
OmniPeek Network Analyzer
,
to capture the wireless scan packet. Then check whether a valid SSID is contained in the
probe request packet that is sent from MT7681 and whether the wireless AP responds
with valid probe response packet.
If there is no valid SSID in the probe request packet, recheck the SSID defined in the Smart
Connection Android or iOS app. You can also print out the following variables to UART in
wifi_state_machine()
when MT7681 is in
WIFI_STATE_SCAN
mode, to check if the input
parameters are correct:
void wifi_state_machine
(
void
)
{
...
if
(
pIoTMlme
->
CurrentWifiState
==
WIFI_STATE_SCAN
)
{
printf_high
(
"%d,%d,%d,%s,%s,%s"
,
pIoTStaCfg
->
AuthMode
,
pIoTStaCfg
->
SsidLen
,
pIoTStaCfg
->
PassphaseLen
,
pIoTStaCfg
->
Ssid
,
pIoTStaCfg
->
Passphase
,
pIoTStaCfg
->
PMK
);
}
...
}
•
if the state switches from
SM=3, Sub=0
to
SM=0, Sub=0
” authentication failed.
•
If the state switches from
SM=4, Sub=0
to
SM=0, Sub=0
association failed.
ior the two cases above, use a network analyzer to check the
Status Code
in the
Auth
Response
or
Assoc Response
packet from the AP or
Reason Code
in the
Deauth
or
Deassoc
packet from MT7681. The meaning of the codes in these packets can be found in
the
802.11 specifications
, sections 8.3, “Format of individual frame types” and 8.4.1.9,
“Status Code field”.
•
if the state switches from
SM=5, Sub=0
to
SM=0, Sub=0
the 4 way handshake failed.
Check whether the password is correct.
•
if the state switches from
SM=6, Sub=0
to
SM=0, Sub=0
DHCP failed and MT7681 cannot
get an IP from the wireless AP. Use a network analyzer to capture the wireless packet and
check whether there is a problem in the DHCP handshake (DHCP discover, DHCP offer,
DHCP ACK, and/or DHCP Request).
•
if no response packet is received, double check the antenna on MT7681 and on AP-router.
