PRODUCTS

 INTRO

This is an applied Engineering exercise that I did just because it seemed interesting and I wanted to experiment with an automotive PC.

   The first thing was to buy a used Suburban I got a GMC 4WD 1500 with a 350 quad 4.  I paid $19K out the door for a 1999 model with 60K miles in very good condition. I bought it in April 2001 so it was 2 years old.  The initial goal was to put an onboard computer with GPS and a 15" LCD display.  The goal then expanded to include VCR and playstation all displaying on the same 15" LCD display.

INVERTER

  After the purchase of this monster the next step was rounding up the parts.

I bought a 750 watt inverter for $79 from Heartland america (www.heartlandAmerica.com). You may be able to find it cheaper nowdays at some automotive parts stores.  This was mounted underneath the drivers seat and the main on/off switch is on the inverter.

LCD MONITOR

 LCD monitor with speakers from Sceptre www.sceptre.com for $350.  It was mounted on the center seat by a body shop friend of mine.

The mounting uses sawed off fence door bracket bought from Home Depot.  This allows the display to be put down for an Horizontal Aegis Map display as below.  The ultimate idea is to have a tilt sensor or horizontal contact sensor along with software on the PC. When the software gets an indication that the display is horizontal it should run the mapping application either Microsoft Streets or Retki Metroguide

SYSTEM UNIT

   System unit from Advanced computer technology (909-738-8191) for $600 this was in 2001. The system was a book pc but with room for 2 slots. It is an Intel Pentium 3 600Mhz with 128 Meg ram, 40 gig hard drive  and DVD.

VIDEO CAPTURE

  Into the spare PCI slot I put in a video capture card (Studio PCTV Pro from Pinnacle Micro). This card can do video cature and also has built in tuner for regular TV.  The reason I bought this rather than a USB video capture was that I thought the USB does not have the speed for video capture and would lead to jerky motion.  In retrospect I would now not use a video capture at all rather use a VGA video mux that can switch in NTSC video or computer video on to the same monitor.  A third alternate would be Samsung's LCD monitor with tuner.  I did buy it from Fry's but I returned it because it was too bulky and heavy.  PCTV pro video tuner has not worked great even with an antenna on the roof.  It may just be that TV tuners do not work well on a moving vehicle. Below is the roof antenna.

  The other problem with it is that the audio out for TV tuner has to be patched over to the built in sound card's line in.  Thus since I had 2.5 audeo/video sources (The TV tuner has video built in but the audio has to be patched) so I had to add an external switch hidden under the seat to do audeo/video switching using a manual 4 to 1 multipoint switch which I bought from fry's.  The switch takes NTSC+Audio from the playstation, NTSC + audio from the VCR and the audio out from the PCTV Pro TV tuner.  The video output of this switch then goes to the PCTV Pro video capture in port.  The audio output goes to the sound card's line in.  In addition I added regular PC speakers since the LCD speakers were not very powerful.  These speakers had AC powered amplifiers and are mounted underneath the middle seat.

WIRELESS KEYBOARD AND MOUSE

    The keyboard is a wireless keyboard from http://www.teknoplanet.com/product.asp?prodid=7943 . it is 900 MHz RF with built in mouse.  The mouse is not as good as a laptop keyboard mouse though.  The whole unit is quite convenient with no messy wires or anything.  It does use up 3 AA batteries and on the negative side it has no on off switch.  end result is that batteries need to be changed every 3 to 4 months.  If someone leaves something on or places it in the seat back such that a key is pressed then the batteries get finished faster.

Additional parts were a Walmart VCR and a spare Playstation video cable.  The VCR had some design issues in as it would not eject tapes if it was sitting on an incline.  The solution was to return it and get a model that had power eject and was not affected by the angle.

SECOND BATTERY

   Although not required but I went and added a second battery to the Suburban. It already has space for it and I believed the alternater  capable of charging both. The second battery runs on a solenoid isolated network which provides rear DC and also runs the inverter.  

   The solenoid isolation circuitry is that that the solenoid is an automotive relay that connects both batteries and allows the second battery to charge once the truck is started. If the truck is off then the inverter is run via the marine battery only.  The alternative to the solenoid was for a high current diode link.  The reason the two batteries need to be isolated is that the marine battery can be deep discharged while the main battery is not touched.  Thus when you want to start the car it is ready.  The advantage of a diode link is that when starting both batteries can work together.  This may be handy in Michigan or Minnesota but is not a significant factor in Southern California.  The matter was clinched when I realized that I could always jumper the two batteries bypassing the solenoid if the main battery was unable to start the car.  The solenoid and the wiring for the second battery was done with heavy gauge wire installed by a pro at my local auto stero installer.  

REAR AC

In addition to the AC port under the driver's seat I added a rear outlet so that we could use it to run a microwave.  That is something I still havent tried.  Although it give a whole new dimension to Rear AC!

GPS

     The initial GPS was bought from www.surpluscomputers.com. They had a special using an older design Mitac mouse like GPS and also Retki Metroguide software.  Retki has since gone out business so Metroguide has since become an orphan.  The software has an aged user interface but even so it is in many ways better than Microsoft Streets which has better maps but the user interface is complex and not suitable for driving.  I copied all the 9 CD's into the metroguide directory so I don't have to worry about swapping CD's.  If you set it up right and give it the correct destination then it will perform an autonav function with voice instruction indicating changes in direction and turns coming up.  Also if you put it in auto tracking mode it shows a nice red car on the map which shows your current location.  One of the problems is that when you zoom out you lose much of the detail.  

  The Mitac GPS also did not do that well. From the start it was finicky and would not lock till 5 and 10 minutes.  Later on the plastic got warped due to heat and then it would sometimes not lock at all.  Finally we were working on a telematics project for a customer www.actplace.net at the end of the project I ended up with an extra Magellan 310 GPS with combo PC/Power cable.  At first I wasn't sure if Metroguide would work with the 310 but after some experimentation with both parties set up as NEMA 4800 baud the Metroguide indicated GPS lock!

  The Magellan 310 is worlds better. It will acquire lock in under a minute and has only two quirks that I did'nt like. First even when provided external power it will not power up if the batteries are dead.  Secondly when you turn on display lighting the external power indicator goes off so the unit switches to battery power. At night it is convenient to leave the display light on but the un-neccessary power drain on the 2 AA's is to put it kindly somewhat draining.

  Also noticed that the vertical accuracy of the 310 has significantly more variance than the horizantal.

MAPPING SOFTWARE

   The installed software consists of Retki metroguide which as can be seen below  has a simple and robust interface.

The other software is Microsoft Streets which is has more detail and more options but is hard to use in a mobile environment.

PROBLEMS

After a year the alternator went which took down both batteries. I put in a replacement heavy duty high current alternator and replaced both batteries.

FINAL PRODUCT

 The final product has been quite successful as I was originally thinking of selling the truck with all these options. Now the kids say no way!

The most successful has been downloading cartoons off the internet and watching DVD's. I went to Kazaa and downloaded old 50's and 60's bugs bunny cartoons and they are prime attraction.  The second attraction has been computer games like freddy fish and Pajama Sam.  The next has been watching VCR although recently the kids don't do much of that. The last was playstation as that is good for only one person and the rest of the kids get bored.

WIRELESS 802.11b

   As far as hooking up to the rest of the house network I simply plugged in a long ethernet cable in the back of the system.  Later on I added an 802.11B USB adapter.  Thus we can do browsing wherever 802.11b is available.

FUTURE IMPROVEMENTS

1. Switch to Windows XP as Windows 98 takes too long to boot.

2. Add voice control. Hardware wise I have added a hardwired microphone just above the driver.  The idea being that the driver should be able to tell the system to run metro guide and then input the destination address via voice.  Once the destination is in the driver should be able to request directions alternate routes etc.

3. Move the 802.11B USB upto the roof. This will require that the system be sealed and a strong magnet be attached to it. Also don't know if the USB hub can take the harsh outdoor environment.

4. Add a USB hub and a USB to serial adapter. Into the serial adapter plug in my Sprint voice data phone so that we can do email while on the road. Even though the speed is slow but the price is right ($10 per month) and it has great coverage.

5. If I had to do it again I would use a video switch or scan convertor in which the inputs are NTSC video and computer VGA. Thus video from a VCR does not require that the computer be on.  Although recently nobody uses VCR's so even that may not be required.  An alternate form would be a USB video capture with tuner and a book PC.  This will reduce the power requirements and simplify the installation.

CONCLUSION

 The conclusion was to get California Custom License Plates indicating our thanks to the Prime Helper on this project.

Copyright (C) 2003 RDLABS