This is the steps I followed to get WiFi working on my embedded board:

Edit your /etc/wpa_supplicant.conf to include your WiFi Access Point info:

ctrl_interface=/var/run/wpa_supplicant
update_config=1
p2p_disabled=1

network={
        ssid="YourWiFiName"
        psk="YourPassword"
        key_mgmt=WPA-PSK
}

Then run the wpa_supplicant command:

# wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant.conf -D nl80211

In my case I don’t have dhclient command in my embedded board, so I used udhcpc command to get IP:

# udhcpc -i wlan0
udhcpc: started, v1.36.1
Dropped protocol specifier '.udhcpc' from 'wlan0.udhcpc'. Using 'wlan0' (ifindex=3).
udhcpc: broadcasting discover
udhcpc: broadcasting select for 192.168.1.58, server 192.168.1.1
udhcpc: lease of 192.168.1.58 obtained from 192.168.1.1, lease time 86400
INFO,/usr/share/udhcpc/default.script: Resetting default routes
SIOCDELRT: No such process
INFO,/usr/share/udhcpc/default.script: Adding DNS 179.0.59.22
INFO,/usr/share/udhcpc/default.script: Adding DNS 179.0.58.22
Dropped protocol specifier '.udhcpc' from 'wlan0.udhcpc'. Using 'wlan0' (ifindex=3).

Finally:

# ping 8.8.8.8