Nomadic FAQ

Henrik I Christensen & David Austin

Contents

1  Nomadic Robotics
    1.1  How do I contact the company?
    1.2  What robots are available?
    1.3  What resources are available?
2  Nomadic Scouts
    2.1  What version are available?
    2.2  My disk crash all the time, why?
    2.3  My disk crashed. How do I get new software?
    2.4  Our network changed, how do I get a new license file?
    2.5  When I attempt to start the Nserver it reports an X server failure and exits. What is the problem?
3  Nomad N200
    3.1  Is the Nomadic software still available?
    3.2  What version of Linux is supported?
4  Nomadic XR4000
    4.1  What version of Linux is supported?
        4.1.1  Is there a way to upgrade the computers to a modern version of Linux?
    4.2  On occation the computer seems to loose connection with the sensors
    4.3  The display panel does not seems to be updated
    4.4  The batteries seems to have a problem with charging. Why?
    4.5  Can I improve the power system on the XR4000?
    4.6  Can I replace the MEMnet communication system?
    4.7  I installed new disks and now I have difficulties booting the system
    4.8  Can I install a SICK sensor on the XR4000?
5  Links to software

1  Nomadic Robotics

1.1  How do I contact the company?

Nomadic Technologies (http://www.robots.com) discontinued their production of robots during November 2000. The company was acquired by 3Com and the robotics part was abandoned. It is consequently no longer possible to get any support from Nomadics:-(

A repository of software, FAQ etc is maintained at sourceforge (http://drobot.sf.net) by a group of volunteers. mailing lists are also available for questions, discussions, etc. The relevant lists are:

1.2  What robots are available?

Nomadic produced the following robotis:

1.3  What resources are available?

At present there are no resources available from Nomadics. There are however a number of resources available through the net. This includes this FAQ and a software repository accessible through sourceforge. (http://drobot.sourceforge.net). There a list of links to other software packages available is also provided.

2  Nomadic Scouts

2.1  What version are available?

There are two basic versions available. The basic scout is a differential drive system with a single caster wheel. This robot has an on embedded controller (68332). The computer is accessible through two serial ports. One using a text protocol and one using a binary protocol. The second version has a on-board computer running linux, whihc is connected to the embedded controller through a serial port. The version of the robot with an on board computer is termed a SuperScout.

Both versions are controlled using the software package Nserver.

2.2  My disk crash all the time, why?

The scouts are well known for frequent crashed. This is due to a design failure in the on-board power system. Apparently the 5V power supply delivers less then 5V (more like 4.3V) which causes write failures on the disk drive, which over time results in disk failures. This was recognised already at the time that Nomadic still was alive. A robot modification kit was made available to selected customers (i.e. when you complained they told you that there is a fix!). The modification involves modifications to the power circuit in the scout and mounting of a fan (to reduce the associated heating problem).

Several have reported that they have replaced four of the sonars by small fans to reduce the heating problem.

A copy of the modification guidelines is available here: TBC. (scanned document). Does anyone have the MsWord file?

2.3  My disk crashed. How do I get new software?

If you happen to have a broken disk. Replace it and carry out the modification mentioned above. Afterwards install a new version of the Nrobot software (available at http://cogvis.nada.kth.se/nomadics/scout/). Then you ought to be up running again.

2.4  Our network changed, how do I get a new license file?

The Nrobot software requires a license file to run. The license file is tied to a particular subnetwork. If you change the network you have to get a new license file. Unfortunately it is not possible to get a new license file. A binary patch for the Nrobot software is available from here (TBC). An open license file is in circulation and you might be able to find a copy by mailing to the list.

2.5  When I attempt to start the Nserver it reports an X server failure and exits. What is the problem?

The Nserver software uses a set of MOTIF fonts. If the server is unable to locate the MOTIF fonts it fails. To solve this problem you have to make sure that your X server has a path to the relevant fonts. To solve this problem you have to issue a commands like:

> Xset +fp "path to motif font files"

3  Nomad N200

3.1  Is the Nomadic software still available?

The software consists of two parts. The device driver and the software interface. The driver is the for the N100 driver board. In addition the interface software comes in two varieties. The Ndirect and the Nclient versions. When linked with the Ndirect the software communicates directly with the motor controller board. When the Nclient version is used the communication is through the graphics user interface.

3.2  What version of Linux is supported?

TBC

4  Nomadic XR4000

4.1  What version of Linux is supported?

The original version of the xrdev software available from Nomadic was developed for the kernel 2.0.24. It is not possible directly to run the software with modern versions of the kernel. Consequently an effort directed by Davis Austin has been aimed at reverse engineering the software so enable compilation of the software with newer version of Linux. The software consists of a kernel module and the user software. The software is available from the http://drobot.sourceforge.net repository. Check the various releases and decide if you want the original version or the bug-fixed version:-)

4.1.1  Is there a way to upgrade the computers to a modern version of Linux?

See previous questions.

4.2  On occation the computer seems to loose connection with the sensors

The ARCNET cables that connects the embedded controllers with the host system are of a cheap variety. This results in frequent loss of connection to the host system. To reduce this problem one may replace the cables with standard telephone tables (RJ11 connectors) and get a significant improvement in performance. The embedded controllers are used for communications with sonars, ir-sensors, the power system, the 3 line display panel and the power on/off buttons.

4.3  The display panel does not seems to be updated

The display panel is only updated when you enter a particular menu item. To solve this problem you need to exit and enter the menu item to get an update.

4.4  The batteries seems to have a problem with charging. Why?

The original Nomadic design did a serial charging of the batteries. This often results in uneven charging of the batteries which in terms ruins the batteries over time. The batteries ought to be charged in parallel rather than in series. Due to this problem the battery life deterioates over time.

4.5  Can I improve the power system on the XR4000?

The short answers is: Ohh yes.

There are several options. First of all the robot normally comes with a single Vicor module for 5V power. For robots equipped with a large number of boards it is worthwhile to install a VICOR booster module (full size 5V module, from the 1st generation series). You can find details on the VICOR modules at http://www.vicr.com. The boster module has part number VI-B30-EU. The power board mounted on the back of the computer casing has room for a booster module. The module can simply be unpacked and installed.

In addition some versions of the XR was delivered with limited capacity cables for the backplane. For these systems it is well worth the effort to upgrade to high quality power cables as this will increase the voltage on the backplane which typically results in a significant improvement in robustness.

4.6  Can I replace the MEMnet communication system?

The MEMnet modules were designed for multi-package delivery of Ethernet packages through shared memory. Unfortunately Nomadic never managed to provide software that utilises this option. Consequently the bandwidth over shared memory is fairly limited and it can easily become a bottleneck. Consequently a performance boost may be achieved through replacement of the memnet boards with regular ethernet boards. It is recommended that 100 Mbit boards are installed.

For wireless communication it is in addition recommended that a Wavelan 802.11 card is installed.

4.7  I installed new disks and now I have difficulties booting the system

The 12V system on the XR4000 has a limited capacity. On power-up the drive require extra power for spin-up which can cause problems. It is thus essential to use disk drives that have limited power requirements as you otherwise might experience boot problems. It would be nice to see a mechanical for timed activitation fo the different disk drives!

4.8  Can I install a SICK sensor on the XR4000?

To install a SICK PLS/LMS scanner on the XR4000 you need to install a 24V VICOR module on the powerboard that is mounted on the back of the card cage. The relevant VICOR module has the part number VI-J33-EW. The board is prepared for the module. On the upper left of the board there is a vacant VICOR slot. Next to it there is a power connector that is used for 24V. Using a set of mounting brackets you can install the SICK scanner in front of the computer cage so that the scanner can ``see'' through the hole in the door. The serial connection from the SICK can be connected to the serial port A on the computer.

5  Links to software


File translated from TEX by TTH, version 2.27.
On 16 Aug 2001, 22:17.