Recommend me a toy set! (Raspberry Pi stuff)



  • I now have in my possession one of the new Raspberry Pi 2's. It has a quad-core ARM processor and 1 GB RAM, along with a ton of GPIO pins. It's just begging to be turned into a robot, WiFi remote-controlled vehicle, or some combination of the two!

    I think some kind of motorized toy kit would be a great starting place. Something like Legos, K'Nex, or Erector Sets, but with some motors and wheels and maybe pulleys or gears. And preferably something that isn't expensive. A generic set (meaning not a kit to build a specific model, like a Batman toy or something) would be ideal.

    Any suggestions? I haven't touched such things in nearly 20 years now.


  • SockDev

    @mott555 said:

    WiFi remote-controlled

    @mott555 said:
    robot

    This

    It can be your own little slavebot, running around, bringing you beer, maiming your enemies…

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  • Make a terminator.


  • I survived the hour long Uno hand

    Something like https://www.sparkfun.com/products/12060 probably... you might want to grab an alamode to interface with arduino bits rather than going off the GPIO ports directly though

    For pi-only, see maybe this article? http://linuxgizmos.com/open-source-robot-kit-taps-raspberry-pi-2/



  • Well I don't have an arduino, I have a Pi...

    EDIT: The robot kit for Pi looks interesting but it's way more than I want to pay.

    Way back when I was young I had an Erector Set that had some motors and could be used to build small wheeled vehicles. Something like that is what I'm after.


  • I survived the hour long Uno hand

    mm-hmm, and if you stick an alamode on top, you can interface with any arduino kit while still having the pi's full capabilities available. Or you can go to the last link I gave you for non-arduino ideas



  • What's the point of interfacing a Pi with an Arduino instead of just using the Pi?



  • My advice is eschew "maker culture", sit your ass on the couch, and watch 1980s action movies.

    EDIT: also your thread does not use the Blakeyrat-approved syntax, "recommend TO me a toy set!"


  • I survived the hour long Uno hand

    The pi has a handful of GPIO pins, so while you CAN drive anything you like off it, you can't use pre-made arduino shields like http://www.robotshop.com/en/arduino-lego-mindstorms-shield-nxshield-d.html



  • I see.

    I'm just looking for something to play with without breaking the bank, just something to start with. I can always get into Arduino stuff later on if I find the Pi to be inadequate.



  • How about you set it up to take a picture of itself after each reboot?



  • @blakeyrat said:

    My advice is eschew "maker culture", sit your ass on the couch, and watch 1980s action movies.

    Yeesh. That attitude is emblematic of 90% of what's wrong with our country -- just when did we lose our will to tinker?

    If you really want to eschew "maker culture", by the way, @mott555, grab one of these. Under $10, equipped with a better CPU and more I/O pins than the Arduino (by far!), and a lot better at real-time control than the Pi ever could be (having a stripped-down desktop OS is a barrier to meeting deadlines). Forewarning, though: it does make you dive in about halfway down the embedded pool, though...



  • @tarunik said:

    Yeesh. That attitude is emblematic of 90% of what's wrong with our country -- just when did we lose our will to tinker?

    In the 1980s, when actions movies got really good. Come on, man, Commando? "I thought you said you'd kill me last!" "I lied!" pushes off cliff


  • Winner of the 2016 Presidential Election

    @mott555 said:

    Any suggestions

    Being a member of this forum you should probably write a roBot to read and write Discourse posts for you

    Filed Under: Not sure if your PI2 has enough ram for processing Discourse, though



  • @Kuro said:

    Filed Under: Not sure if your PI2 has enough ram for processing Discourse, though

    Probably not, it only has 1 GB RAM. If it uses a pagefile the MicroSD card would be worn out within a week.


  • SockDev

    @Kuro said:

    Not sure if your PI2 has enough ram for processing Discourse, though

    No need: just use the message bus and the JSON API

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  • SockDev

    @sockbot runs 5 instances plus 1 likebot instance on a 1GB Digital Ocean Droplet with gobs of memory to spare.

    assuming processor is powerful enough (and it looks like it is) there should be no problems running her, or any other bot, on an rpi



  • @RaceProUK said:

    No need: just use the message bus and the JSON API

    Or give it hands for manipulating a keyboard and have it OCR a computer monitor with Discourse up.


  • Winner of the 2016 Presidential Election

    Would you please stop trying to ruin a perfectly fine Filed Under Joke? @mott555 understood it :smiley:

    Filed Under: No System ever is good enough to parse Discourse. You guys are just lucky your servers haven't died, yet

    @mott555 said:

    OCR a computer monitor with Discourse up.

    Seeing as how Discourse changes stuff every release thats probably the worst way of doing anything!



  • Realistically, I don't want to use the Pi for any mundane programming tasks, I already have a beefy ESXi server for that stuff. I'm more interested in doing something robot-like using the GPIO pins.



  • Random thought: If there's a GPS module for the Pi, I could convert a remote-controlled blimp into an autopiloted robot. But the two major issues to work out are upgrading the balloon to hold the weight of whatever battery system the Pi would need, and of course understanding any legal issues about a robotic blimp flying over Omaha.



  • @mott555 said:

    and of course understanding any legal issues about a robotic blimp flying over Omaha.

    Just make sure you wipe down any latent fingerprints before flying.


  • SockDev

    @mott555 said:

    there's a GPS module for the P

    yep. several. this is just the first google hit.



  • @mott555 said:

    understanding any legal issues about a robotic blimp flying over Omaha.



  • Hmm, here are a couple ideas:

    http://ecx.images-amazon.com/images/I/6149rlpKpGL.SL1000.jpg

    A tank with an Airsoft cannon! Though I'd consider replacing the cannon with a single-shot Nerf dart gun.

    Or,

    a pair of tanks with IR blasters and sensors. Could be interesting to make them remote-controlled via a client app and WiFi, and battle someone when you have to use sensors and cameras on the tank itself instead of your own eyes. This would also be a good project to try AI on.



  • And here's an even more viable idea:

    A simple tracked chassis with no electronics for under $20! Looks small though, judging from the AA batteries in the image.


  • Discourse touched me in a no-no place

    @accalia said:

    @sockbot runs 5 instances plus 1 likebot instance on a 1GB Digital Ocean Droplet with gobs of memory to spare.

    Unless a single instance is restoring a decompressed 1.5GB database .sql.

    Seriously - it's not funny at 0400UTC if I'm actually awake sitting on my sofa trying to use my laptop....

    The latter of which doesn't happen too frequently at 0400, which is why that time was picked. Memory usage of 2G+ for node.js was impressive though


  • SockDev

    @PJH said:

    Unless a single instance is restoring a decompressed 1.5GB database .sql.

    Seriously - it's not funny at 0400UTC if I'm actually awake sitting on my sofa trying to use my laptop....

    The latter of which doesn't happen too frequently at 0400, which is why that time was picked. Memory usage of 2G+ for node.js was impressive though

    touche.

    i imagine the laptop gets mighty warm too at about that time. ;-)


  • SockDev

    @accalia said:

    i imagine the laptop gets mighty warm too at about that time

    At least his coffee won't go cold
    https://www.youtube.com/watch?v=g-4-gLlF0uw


    I use that often enough; might have to set up a script or something…

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  • Discourse touched me in a no-no place

    I turn the central heating off.

    I think I'll have to turn the air conditioner on in summer...


  • Discourse touched me in a no-no place

    @RaceProUK said:

    At least his coffee won't go cold



  • My two ESXi boxes heat my apartment in winter, I don't have to turn my heater on until it's under 10° outside. If it's warmer than that I have to keep a window cracked.


  • SockDev

    you know i'm more than happy to give you space on one of my droplets if you want to get that instance off your laptop.

    of course then that whole trust with data issue rears it's head. ;-)


  • Discourse touched me in a no-no place

    @accalia said:

    you know i'm more than happy to give you space on one of my droplets if you want to get that instance off your laptop.

    I have a desktop running 2 VM's (one Windows guest, faster than the hosted instance we had previously) along with the host OS, and it's running my Discourse instance - if my laptop starts feeling a bit feeble I'll simply move SockBot over there. :smile:


  • SockDev

    or that works too. ;-)



  • @mott555 said:

    Random thought: If there's a GPS module for the Pi, I could convert a remote-controlled blimp into an autopiloted robot. But the two major issues to work out are upgrading the balloon to hold the weight of whatever battery system the Pi would need, and of course understanding any legal issues about a robotic blimp flying over Omaha.

    The rules for this are still in flux -- the Part 107 rules for commercial small UASes (less than 55lbs) just hit the NPRM stage, and the operational rules for noncommercial small UASes are similar (below 400', no closer than 5 miles to an airport, not near people or crowds, and line-of-sight VFR). A blimp over 55lbs, of course, would be treated as an airplane, basically -- and I really don't know how a full-sized UAS in controlled (Class C) airspace would work, aside from the same trappings you'd need to have a manned blimp over Omaha. (I.e. an appropriately rated pilot operating the thing, a working transponder and two-way radio with ATC, and airworthiness certification complete with N-number.)

    OTOH -- perhaps this'd be good motivation to get your pilot's license?



  • @tarunik said:

    OTOH -- perhaps this'd be good motivation to get your pilot's license?

    I have things like this on my bucket list, but my student loans and truck loan need to be 100% gone first.



  • Yeah -- I don't have those wormbuckets to worry about, but I have a sneaking suspicion that I'm ineligible for a third class medical certificate, which is a bit of a buzzkill...


  • BINNED

    @RaceProUK said:

    I use that often enough; might have to set up a script or something…

    Expand the emoji bot to recognize :rimshot:?

    Use your resources wisely, young one.



  • I ordered this chassis along with the dual-motor-gearbox addon thingy which gives the treads independent power.

    I'm not sure exactly what I'm going to do yet or where this project will end, so pardon my rambling, but for starters I figure I'll whip up a basic console application to control it. Then I can SSH into it from my PC and remote-control it over WiFi. Eventually I'll build a client app utilizing sockets. Could be a .NET thing on Windows, or a Node.JS application serving a web page to the client.

    Obviously the Pi's GPIO pins are not going to output enough power to drive the motors, so I want to use some transistors. Not standard relays, but transistors, so theoretically I can throttle the motors using PWM. Can any of you hardware guys recommend some basic transistors? As far as I know, the motors run on a pair of 1.5V AA batteries so they won't be switching a ton of power, but I obviously don't want them to explode under rapid switching.

    Next up I'll want to purchase one of the Pi camera units and experiment with it. Tamiya makes a low-speed motor/gearbox unit that I could use to build a turret, but this might be a good opportunity to investigate stepper motors so I can control the range of motion and prevent the user from twisting the camera's ribbon cable to pieces.

    At the same time I'll probably play with some LEDs to add running lights and headlights. If I get the NoIR camera, I'll want some infrared LEDs too. Not sure yet, I think the Pi can only support one camera at a time but if there's a way around that (perhaps using a GPIO to switch camera contacts via a switching transistor?) I'd like to have both camera types.

    After this, I'm not sure. Perhaps a small speaker and amplifier and implement a text-to-speech unit? Additional sensors and experiment with some basic robot AI? Mount a couple stripped-down single-shot Nerf dart guns to the turret? Grappling arm if I have enough GPIOs left by that point?


  • SockDev

    @mott555 said:

    Not standard relays, but transistors, so theoretically I can throttle the motors using PWM.

    Work out how much power the motors will draw, add about 25-50%, and buy transistors rated for that power.

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  • And I totally forgot to mention (and I forgot to bookmark the site, too) but someone has ported a real-time operating system to the Raspberry Pi. That is definitely worth looking at (eventually) since I'm planning to directly control hardware via the Pi's GPIOs instead of having some other controller do it for me.

    Though the Pi 2 has a quad-core CPU, so an RTOS may not be necessary. Careful use of threading and thread priority/affinity could be (ab)used as a shim if I notice significant control latency.



  • @mott555 said:

    a robot, WiFi remote-controlled vehicle, or some combination of the two!

    But a vehicle is a robot! This is so redundant!!!!!!!! PEDANT_OVERFLOW_ERROR



  • I guess when I say robot, I mean autonomous, whereas remote control means I'm directly controlling its actions.



  • A robot has sensors and follows a stored program, while an ROV is simply remotely operated.

    Yes, Robot Wars should have been called ROV Wars.
    Was great fun though. Nothing like seeing your creation flying through the air, pieces everywhere but still in the fight.



  • My chassis came today. This thing is perfect! Lots of assembly required though, just like any model kit, which isn't what I expected. Oh well, it didn't take me too long to put together and I like models anyway.

    The basic kit only came with a single motor and gearbox, and as such the unit can only drive forwards or reverse and cannot turn. I also ordered the double motor/gearbox kit which allows the treads to operate independently but have not assembled it yet. The basic kit and extra motors/gearbox were only about $30 total, so not too bad at all, much better than my original plan to purchase a decent R/C car from a toy store and strip it down, or figure out something with K'Nex or Legos.

    The gearbox has fast and slow modes, but you have to completely disassemble it and rearrange gears to change it. I used slow mode, and it is certainly slow. I'll have to switch it over to fast mode to compare, and as long as it has enough torque eventually I can throttle it down via PWM if I need to. I measured average current at 0.3 A and stall current around 1 A, so it doesn't look like I'll need beefy transistors to PWM this.

    This looks like it was meant to be, here's a picture with the Raspberry Pi sitting on top for a size comparison:

    I put in an order for Pi accessories to get these slapped together properly. I ordered a pack of transistors, a breadboard, case, a ribbon cable and breakout board for the GPIO block, some LEDs including IR ones, and the NoIR camera which is sensitive to IR light as well as visible. I already have a bag of leftover resistors from guitar amplifier mods I purchased. Eventually I'll need a battery pack and WiFi module but I can make do without for now.



  • As I may have mentioned earlier on other threads, this project stalled due to me being unable to figure out my motor controller IC's. I thought I had them wired up correctly but nothing would happen when I sent signals to the IC. This was like two months ago.

    One of my buddies (who is quite computer illiterate, but knows wiring well) wanted to see the tank in action so we dug it out, and he pretty quickly noticed that the pins I was using to hold the IC board to my breadboard didn't actually make electrical contact with the IC board! :headdesk: After few minutes worth of soldering, I can now control the vehicle via keyboard input to a Python script.

    I might put together a quick YouTube video to show it off, but first I want to get a more permanent board together that easily mounts to the chassis, and wire up a few LED running lights. Once that's done it should be controllable via the Python script over SSH, and I can start researching how to build a socket server in C to control everything with an actual client application instead of an SSH session.



  • @mott555 said:

    I can start researching how to build a socket server in C

    HTH


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