My hostapd config

hostapd.conf

# Set up some logging. VERY useful to see why things aren't working.
logger_syslog=-1
logger_syslog_level=2
logger_stdout=-1
logger_stdout_level=2

# Which interface to use and which bridge to join
interface=wlan0
bridge=br0

# Use this driver for AP stuff. This corresponds to the mac80211 driver
# which most newer cards support.
driver=nl80211

# 802.11 mode and channel, pretty self-explanatory
hw_mode=g
country_code=US
channel=1

# Set and broadcast the SSID. Specify UTF8 and printf format for weird SSIDs 
ssid2="test_net" 
utf8_ssid=1
ignore_broadcast_ssid=0

# 802.11N stuff - Try 40 MHz channels, fall back to 20 MHz
ieee80211n=1
ht_capab=[HT40-][SHORT-GI-20][SHORT-GI-40]

# WPA Authentication
auth_algs=1                 # Open authentication, no WEP
wpa=2                       # WPA2 only, set to 3 for WPA+WPA2
wpa_passphrase=xxxxxxxxxxx  # Hah! Like I'd put this in a gist.
wpa_psk=0123456789abcdef01  # For hash of shared secret
wpa_psk_file=/etc/hostapd.psk # Even better, store the hash in a file
wpa_key_mgmt=WPA-PSK WPA-PSK-SHA256
rsn_pairwise=CCMP           # Cipher for WPA2 (AES in this case)


# Don't use a MAC ACL/Radius
macaddr_acl=0
wpa_psk_radius=0

# Lets clients cross talk
ap_isolate=0