Big Trak Gets A New Brain

If you were a kid in the 1980s you might have been lucky enough to score a Big Trak — a robotic toy you could program using a membrane keyboard to do 16 different motions. [Howard] has one, but not wanting to live with a 16-step program, he gave it a brain transplant with an Arduino and brought it on [RetroManCave’s] video blog and you can see that below.

If you want to duplicate the feat and your mom already cleaned your room to make it a craft shop, you can score one on eBay or there’s even a new replica version available, although it isn’t inexpensive. The code you need is on GitHub.

The CPU isn’t the only upgrade, as the updated Big Trak has an OLED display. [Howard] plans to add either WiFi or Bluetooth and wire the keyboard up to the onboard Arduino. [Howard] shows the inside and there is a lot of room by today’s standards. Of course, we wanted to see the original PCB, but it was nowhere to be found. Luckily, we found an image of the single-sided PCB on Wikipedia, so if you are like us, you can see it below, under the video.

There’s no wiring diagram that we could see, but from the Arduino code you can back out what the connections are to the sonar, the OLED display, and the new motor drivers for the original motors.

Oddly enough, this isn’t the first Big Trak that has made it to the pages of Hackaday. Of course, we have no shortage of hacked toy robots.

Bigtrak PCB Image – [Sergio Calleja] CC BY-SA 2.0


30 thoughts on “Big Trak Gets A New Brain

  1. The Big Trak drive mechanism needs to be looked at by everyone.

    The left and right motors are inexpensive basic motors. These motors turn about the same speed all by themselves.

    The way the motors were kept spinning at exactly the same RPM (to insure the path was straight) was they had a magnet that spun on the opposite end of the gears. The N pole on one motor kept the S pole on the other motor all lined up. When the motor were supposed to turn at a different speed, there was no problem, the magnets weren’t that strong.

    Simple, and easy to make.

      1. Back in the late 80’s the Boy Scouts magazine ran an article on building a robot from a rectangular plastic trash can and a couple of Big Trak motor/gearbox units. It didn’t say that’s what they were but the source was obvious to me. It listed where to buy each of the parts.

  2. “If you want to duplicate the feat and your mom already cleaned your room to make it a craft shop…”

    “There’s no wiring diagram that we could see”
    Maybe his mom threw it away during the cleaning?

  3. No one else is gonna say it?
    My big problem with the BigTrak is that the BigTrak did lack trek.

    And I want to know:
    Just how big are the track of a BigTrak if a BigTrak did have track?

  4. Steve Ciarcia built an RF link to the Big Trak, it’s in the Vol III book pg 80, and February ? of some yr, search for “Steve Ciarcia byte big trak” into your favorite search engine

    1. I was going to say that he did something with the BigTrak, but I couldn’t remember what he did with it. has a large collection of old computer magazines, so the Byte might be there.

      I seem to recall Steve Ciarcia using cordless drills to propel something, but I’m blank about the specific project, so maybe it was from someone else. About the same period, I’d say.


  5. bigtrak is one of the few memories i still have from my early preschool days in the early 80s, they had one of those and I was absolutely obsessed with it. I probably decided to be a programmer right there.
    Doing a quick ebay search, it seems these have become quite rare.

    1. I remember my bigtrack programming tryout with mixed memory.
      Ok it was fun the first time, after that it was so tedious and frustrating that I wished it had remote controller instead…

  6. Wow… I remember wanting one when I spotted one at a garage sale in the 80’s. I asked for and received a Radio Shack “programmable” Space Tank instead. I was just on the wrong side of too young to fully realize that programmable actually meant using these yellow disks to control the tank. Should mention the tank actually didn’t go straight. It curved ever so slightly even without a disk. Frustrated the hell out of me.

    Put that sucker away and forgot all about it until today.

  7. I Love My Toys Big Time.

    I have a hole fleet of them. I have 5 tanks, 3 cranses, 6 little 6 wheeled cars,( great to start off with with a esp8266 shield)
    estavaging equipment. back up to 6 rumbas, And lots of cars. And some other things that are strang.
    I’ve been playing with the roombas for now.
    It will be so much fun when I get them all going.

    I do have enuf cameras and ESP8266s, ESP32’s, PI types of computers to get then to move see and talk and see each other.
    I’m getting there very slowly but getting there.

  8. I had a Kenner light beam car that had two photo cells on the roof and you controlled by shining a flash light on the roof (forward, left and right only). I took it apart to see how it worked. Unfortunately, my skills at putting things back together were not good and it never worked again. I still have the circuit board in my parts cabinet

  9. Does anyone remember that everyday electronics magazines did a series on the 80’s on rewiring the brains of a bigtrak with a meaty processor, LCD, etc. For the life of me I can’t seem to find it anymore! :(

  10. I have half a dozen BigTraks and a Jnr, which I want to upgrade because to my mind, the originals have two huge faults.

    As mac012345 said above, it’s fun for a little while but very soon it becomes apparent it’s the driver, not the BigTrak, that’s doing anything interesting… it’s far too big to run round most people\s kitchen tables and on the living-room floor, how many routes can you really rack your brain to design for it?

    As an aid for teaching basic programming it’s magnificent, and I’ve heard of several local schools still using it that way… and isn’t the fact that’s not what it was sold for, half the reason it’s no longer available?

    Either way it if was really a tracked vehicle it would at leat twice as much fun.

    Because it’s not tracked, and doesn’t pretend to be, using the middle wheels for the drive was a disastrous idea, which should have been obvious n the drawing board, if not in basic testing.

    Because the drive is all through the central wheels, the poor thing will automatically stop every time it hits more than the slightest slope, clearly negating the idea of marketing it as any kind of “trak” in the first place. At least if the drive was through the front or rear, rather than the middle wheels, it would crawl up many slopes and a real-wheel drive would let it crawl over many a gentle peak, too.

    Rigging remote control wasn’t too difficult – basically, buy almost any cheap RC vehicle from a charity shop or e-Bay, snip out its control board and hack that into your BigTrak as either an option or a replacement for the factory board.

    I remain confident that fitting tracks which offer drive to all three axles will be possible, and thus far, do I feel frustrated, or what?

    My first mod was simply to stretch a huge rubber band round all three wheels. Nah… that slipped before it moved a millimetre.

    I rigged some idling pressor wheels to improve the tension but that’s still highly dubious, and works only on pairs of middle and either front or rear wheels, not all three.

    Clearly, some combination of adapting or replacing the original wheels and either making a new track belt or adapting one from something else will eventually work. Nevertheless for Goodness’ sake, how could a manufacturer even half-way capable of designing BigTrak in the first place have missed either the technicalities or the marketing possibilities

    Yes I did see various versions of “BigTrak is back” some of which offered phone control and that not too expensively… none of which is actually available.

    If anyone has thoughts that might make either controls or drives better, would you mind sharing?

  11. Not sure if it was Big Trak or Apple Logo that gave me the programming bug, but I loved both. Today, I wish there were a “Big Trak of the Skies” that would let me program a flight plan for navigating around my house, out the window, around the neighborhood, through the park, buzz the beach, and back. Educators should be able to geofence it, and it should have multi-vehicle mode out of the box for group experiments.

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