Tiny remote control cars burst onto the scene from time to time, often sold from mall kiosks and covered in garish stickers. However, sometimes it’s more fun to build than to buy. [diorama111] clearly fits into this camp, building a tiny 1:150 scale RC car from the ground up.
The build starts with a Tomy 1:150 model Toyota Crown / Avalon. However, only the outer shell remain. From giving the wheels rubber tires and fabricating a delicate steering assembly, to adding motors for both locomotion and turning, the mechanical build is on point. But seeing the ATtiny1616 is deadbugged with a DRV8835 motor driver, with the SMD parts hooked up with magnet wire to save the most space possible is equally impressive. A PIC79603 IR module is used to receive the commands to drive the car.
Wanting to lower the barrier of entry for developing software for self-driving cars, he based his design off of something you’re likely to have lying around already: a smartphone. He cites the Google Cardboard project for his inspiration, with how it made VR more accessible without needing expensive hardware. The phone is able to control the actuators and wheel motors through a custom board, which it talks to via a Bluetooth connection. And since the camera points up in the way the phone is mounted in the frame, [Piotr] came up with a really clever solution of using a mirror as a periscope so the car can see in front of itself.
The software here has two parts, though the phone app one does little more than just serve as an interface by sending off a video feed to be processed. The whole computer vision processing is done on the desktop part, and it allows [Piotr] to do some fun things like using reinforcement learning to keep the car driving as long as possible without crashing. This is achieved by making the algorithm observe the images coming from the phone and giving it negative reward whenever an accelerometer detects a collision. Another experiment he’s done is use a QR tag on top of the car, visible to a fixed overhead camera, to determine the car’s position in the room.
What’s more fun, driving RC cars around on rugged terrain, or having a paintball battle? How about doing both at the same time by making an RC controlled, paintball firing tank? [Nate] from the King of Random YouTube channel did just that by mounting a modified paintball gun to a stripped-down RC car, adding an RC trigger to remotely fire the gun, and covering it all in EVA foam armor in the shape of a tank. And then he did it again so that he’d have someone to battle against.
He walks through the full build in the first video below, but here are some things that stood out for us. It took some fiddling to get a servo to pull the gun trigger but how could he remotely control the servo? For that, he took over the car’s RC receiver signal for controlling audio and made it turn on and off the servo instead. We also like his use of aluminum bar. This stuff is available in the hardware section at stores like Home Depot and is easy to cut and bend. You can see it used here for mounting Wimshurst machine parts to a bicycle, and in this hack, [Nate] used it to mount the paintball gun rigidly to the car frame. He did surprise us when he used rivets instead of nuts and bolts to hold the frame together. That’s not something you see often, and it worked great.
As we said, he made two of them. In the second video below, watch the tanks in action as [Nate] and fellow YouTuber [Stuart Edge] have a tank battle in the desert.
In the drag racing world, a Christmas tree is the post at the start line that sequentially lights up a set of yellow lights followed shortly after by a green light to tell the drivers to go, the lights obviously giving it its seasonal name. Included at the base of the tree are lasers to detect the presence of the cars.
[Mike] not only made his own Christmas tree for his RC cars, but he even made an end-of-track circuit with LED displays telling the cars how long they took. Both start and finish hardware are controlled by Pololu Wixel boards which has TI CC2511F32 microcontrollers with built-in 2.4 GHz radios for wireless communications.
In addition to the LEDs, the Christmas tree has a laser beam using a 650nm red laser diode for each car at the start line that’s aimed at a TEPT5600 phototransistor. If a car crosses its beam before the green light then a red light signals the car’s disqualification.
The end-of-track circuit has 7-segment displays for each car’s time. [Mike] designed the system so that the Christmas tree’s microcontroller tells the end-of-track circuit’s microcontroller when to reset the times, start the times, and clear the times should there be a disqualification. The finish line controller has lasers and phototransistors just like the starting line to stop the timers.
Oh, and did we mention that he also included 1980’s car racing game sounds? To see and hear it all in action check out the video after the break. If the cars seem a little drunk it’s because pushing left or right on the controller turns the wheel’s fully left or right.
It’s a dream come true: remote control of a real car. Besides being a lot of fun, a life-size RC vehicle has some practical applications, like performing rescue operations or delivering supplies to dangerous areas. For [Carter], [Dave], [Ryan], and [Sean], the dream became reality in the span of 24 caffeine-and-chicken-finger-fueled hours during an Ohio State University hackathon. They dubbed the system MagiKarpet because it sits in place of the floor mat and runs on pixies.
The plan was to control the throttle, brake, and steering of a Chevy Cobalt using a PlayStation controller. For added fun, a camera mounted high above the back bumper would provide a third-person view, and this feed would be displayed on a monitor in the backseat. Everything is controlled by an Arduino Mega. A beefy linear actuator works the brake and is attached temporarily with a band of Shapelock that slips around the pedal. The throttle is pushed by a lever attached to a car window motor. Another motor connects to the steering wheel with cables that can turn it 90° left and right. Although the build was successful, they ran into a couple of issues. But what’s a hackathon experience without a few problems?
The linear actuator was jammed for about an hour after some early testing, but they got it unstuck. The PS controller was borked, so they had to roll their own joysticks. The school wouldn’t let them actually drive it around because of safety (killjoys but we get it), so they put it up on a jack to demonstrate it for the judges. They took second place, though we can’t imagine what would have beat this. Check out the complete build video after the break.
You might remember these guys from last year around this time. They took first place at the same hackathon with Robottermilk Puncakes, a app-controlled pancake machine. Now that you’re hungry for pancakes, feast your eyes on this endless one.
[Emil Kalstø] has a pretty solid remote control car. We don’t mean a little car with a handheld remote you can drive around the neighborhood. [Emil’s] car has a camera and a cell phone so that it can go anywhere there’s 3G or 4G networking available.
The video (see below) shows the results (along with [Emil’s] little brother acting as a safety officer). The video offers tantalizing detail you might find useful if you want to reproduce a similar vehicle. However, it stops short of providing complete details.
The two batteries onboard will power the vehicle for over 20 hours of continuous use. The 30W motor is reduced with a chain drive to go about “walking speed.” There’s a Raspberry Pi with a Huawei 3G USB dongle onboard and [Emil] uses an XBox controller to do the steering from the warmth of his living room. Of course, a Pi can’t handle a big motor like that directly, so a Phidgets USB motor controller does the hard work. The software is written using Node.js.
The camera mount can swivel 230 degrees on a servo so that the operator can scan the road ahead. The video mentions that steering the car required a heavy-duty servo with metal gears (an earlier attempt with nylon gears didn’t work out).
Overall, it looks like a solid build. We hope [Emil] will share code and more details soon. If you can’t wait (and your insurance is paid up), you might have a go at an even bigger car. Surprisingly, there’s more than one example of that.