The link between the ground station (the PSAS Field server) and the rocket is done under "Ad-Hoc Demo Mode". Ad-Hoc Demo mode is only available on wireless cards with Lucent Orinoco chipsets, so the field server obviously has one of these in it. Usually we have the field server routing packets from laptops via a WAP to the ad-hoc demo mode network to the rocket... but occasionally we want to talk directly to the rocket using a laptop.
This text describes how to get your wireless card setup in that mode under Debian Linux; feel free to add info about other operating environments as necessary.
The first step is to get the kernel, pcmcia, and wireless tools. See "Standard PSAS devel. environment" in DevelopmentEnvironmentForLv2 for details on that. If that doesn't get you the orinoco modules (look for
/lib/modules/`uname -r`/kernel/drivers/net/wireless; under 2.6 this will be
*.ko), you'll have to recompile the kernel with wireless support (CONFIG_NET_RADIO) and Hermes PCMCIA support (CONFIG_PCMCIA_HERMES; creates orinoco_cs.o module). Actually, it might just work best to say support everything remotely related to wireless networking as a module so that you don't have to worry about recompiling ten times just to get the right stuff.
This part assumes your wireless interface is
eth0. If it's not, then replace every instance of eth0 below with the appropriate interface (e.g., eth1).
/etc/network/interfaces file should have something like this for your wireless card:
iface eth0 inet dhcp
Now edit your
/etc/network/interfaces so it includes this:
# The Rocket Configuration iface rocket inet static pre-up iwconfig eth0 mode ad-hoc pre-up iwconfig eth0 rate 2M pre-up iwconfig eth0 channel 1 pre-up iwpriv eth0 set_port3 1 pre-up iwconfig eth0 sens 3 address 10.0.0.42 netmask 255.0.0.0 broadcast 10.0.0.255 network 10.0.0.0
Usually you run
sudo ifup eth0 to get your default interface setup (this happens normally on boot if you have
auto eth0 in your
/etc/network/interfaces file). With the above stanza, you can now run
ifup eth0=rocket to get your wireless interface into "rocket mode".
The card should be up and running with all the correct settings. You can verify those settings by looking at the output of
iwconfig eth0. (Ignore the ESSID.)
And to check everything, try to ping the rocket:
When you want to get your card back into normal mode, you should be able to
sudo ifdown eth0 and
sudo ifup eth0. If this doesn't work, you may need to remove and reinsert your card so it forgets all the settings from above.