Tools -> LX200
This tool provides basic GOTO control of a Meade LX200-compatible telescope
from your Zaurus.
The following steps are required before PSC can operate the telescope:
- Free the serial port for PSC. Zaurus normally boots up in
runlevel 5, which automatically starts a process called pppd that uses
the serial port for PPP networking. This must be shut off before PSC can use
the serial port for telescope control. One way to do this is to
perform a soft reset. A soft reset is nothing more than the procedure used
for changing the Zaurus battery but this time we add one extra step. Note
that a soft reset should not lose your addresses or other stored
information but please we take no responsibility if this happens
Also, please read through all the following steps before performing them
because one of them only gives you a few seconds to act.
- quit all applications
- just as you would if you were about to replace the battery, slide the
switch on the rear of the Zaurus to the position labeled Replace
Battery, wait a few seconds for the screen to go black, then return the
switch to the position labeled Normal Operation.
- slide open the Zaurus keyboard, locate the /? key.
- turn the Zaurus on
- Zaurus will now do a soft boot. Messages in white text on a black
background will scroll by. After a few seconds the last message will be
a line that says Wait ... and counts down from 5. Before it reaches
0 press the /? key. The countdown will stop and you will see a little menu.
Now you can relax, the menu will just wait for you to type a key. Look
through the entries and choose the one that makes /dev/tty0 free.
On my Z this is done by pressing the e key, I hear from others it
can be the t key, so your mileage will vary. Whatever it is, press
that key now.
- Zaurus will continue to boot as usual.
- Connect your Zaurus to the LX200. This will require a
suitable RS232 cable. We suggest the ZThinCableTM from
This cable allows the Zaurus keyboard tray to be open while connected,
whereas the Sharp cable requires the keyboard to stay closed.
- Set up the LX200. Power on the telescope and perform all necessary
setup functions so it operates correctly and points well from the hand paddle
Note 1: This procedure need only be done whenever the device is soft reset. Just
powering down or suspending the Zaurus during normal operation will not affect
the availability of the serial port.
Note 2: to restore the PPP client, perform a soft reset again but just let
the Wait message count down to 0 and let it proceed on its own.
Telescope Window Commands
After performing Initial Preparation above, tap Tools->LX200 to
bring up the telescope control window.
Connect. The telescope communication will be attempted and if
successful, the current pointing position of the telescope will be
displayed on a regular basis in the box at the top. While connected, a
marker is also drawn on the Sky chart to show the telescope position.
Whether it is visible depends in part on the next option.
Screen follows scope sets whether the Sky chart will automatically
be repointed as needed so the telescope marker is always on the screen. This
effect is nice for following the field while tracking or watching a slew
path, but you will want to turn it off when planning an observation in a
part of the sky far from that which the telescope is currently pointing.
Goto park will command the telescope to the southern horizon
pointing up to the celestial equator. Parking the telescope in this
manner before turning off its power will simplying using the telescope
Send latitude and longitude will transmit these values as currently
defined in Personal Sky Chart to the telescope.
Send Z date and time will transmit the time of the Zaurus (not PSC)
to the telescope.
Sky Map Control
When the telescope is connected then the Sky popup menu will include an
entry to point the telescope to the tapped object or location.
See Sky popup menu.