RP6 ROBOT SYSTEM - 3. RobotLoader 2
3.3.1. Configure Access Point
The configuration of the WLAN access points varies from one model to another. We
recommend to read the accompanying documentation. If possible you should use
fixed IP addresses (DHCP deactivated) which makes it easier to address the WLAN
module. The RobotLoader software can find the WLAN module automatically via the
dialog box
Options->Discover WIFI Devices
. There, the UDP status messages sent by
the WLAN module are displayed as a list. Any number of RP6 WLAN modules can be
listed here. Click on the “Add” button to add the IP to the list in the WIFI loader tab.
This is particularly useful if you use DHCP. For own applications, it is easier though to
use static IP addresses.
WPA is mandatory as encryption mode!
Do not use WEP! This encryption mode
has been cracked a long time ago and is no serious obstacle anymore. Of course don't
use the standard settings of the router as a password but find a good one by yourself
(by the way, the password shown in the figure is not a very good example ;-) ).
Choose the other settings according to your network. You can try out various WLAN
channels if some are strongly disturbed by neighbor networks or other sources of in-
terference. Channel 1, 6 or 11 are not overlapping in the 2.4GHz band.
Tip:
On a Notebook with WLAN you can use e.g.. inSSIDer
http://www.metageek.net/products/inssider/
(for Linux available as a BETA version) to display the channel assign-
ment and select a relatively free channel.
Another tip:
If the access point is only used for the robot control, you can also use
the slower 802.11b mode. The advantage is that the range is slightly
increased. However you need to manually change the configuration of
the RN-171 module. The access point can also be set to b/g (or b/g/n)
mixed mode. However this mode reduces the transmission speed of
units that work in the faster 802.11g/n mode.
In the WLAN command-line (or in the configuration script)
set wlan rate 8
activates the normal 6MBit/s 802.11g mode (6MBit/s is the slowest
rate in 802.11g mode, allows higher transmit range) and
set wlan rate 1
switches to 2MBit/s 802.11b. You can not use that mode if you have
configured your router to 802.11g only!
Higher quality dual band routers featuring two HF modules allow to as-
sign the faster devices to a separate channel.
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