Sometimes you start building, and the project evolves. Layers upon layers of functionality accrue, accrete, and otherwise just pile up. Or at least we’re guessing that’s what happened with [Varun Kumar]’s sweet “Surveillance Car Controlled by DTMF“.
In case you haven’t ever dug into not-so-ancient telephony, Dual-tone, multi-frequency signalling is what made old touch-tone phones work. DTMF, as you’d guess, encodes data in audio by playing two pitches at once. Eight tones are mapped to sixteen numbers by using a matrix that looks not coincidentally like the old phone keypad (but with an extra column). One pitch corresponds to a column, and one to a row. Figure out which tones are playing, and you’ve decoded the signal.
Anyway, you can get DTMF decoder chips for pennies on eBay, and they make a great remote-control interface for a simple robot, which is presumably how [Varun] got started. And then he decided that he needed a cell phone on the robot to send back video over WiFi, and realized that he could also use the phone as a remote controller. So he downloaded a DTMF-tone-generator app to the phone, which he then controls over VNC. Details on GitHub.
Continue reading “DTMF Robot Makes Rube Goldberg Proud”
[Aldric Négrier] wrote in to let us know that his DriveMyPhone project has been open sourced. The project is a part telepresence, part remote-controlled vehicle, part robotic rover concept on which he says “I spent more time […] than I should have.” He has shared not just the CAD files, but every detail including tips on assembly. He admits that maybe a robotic chassis for a smartphone might not seem like a particularly new idea today, but it was “an idea with more potential” back in 2010 when he first started.
The chassis is made to cradle a smartphone. Fire up your favorite videoconferencing software and you have a way to see where you’re going as well as hear (and speak to) your surroundings. Bluetooth communications between the phone and the chassis provides wireless control. That being said, this unit is clearly designed to be able to deal with far more challenging terrain than the average office environment, and has been designed to not only be attractive, but to be as accessible and open to repurposing and modification as possible.
Continue reading “Smartphone-based Robotic Rover Project goes Open Source”
This DIY mailbox pretty much has it all. Not only is it waterproof and secure, it’s beautifully built and unlikely to arouse the suspicion of or induce fear in the mailman.
It’s made of 2mm thick sheet metal and features accents made of merri, a rather nice blood wood native to Western Australia. [George] of Make It Extreme built this mailbox primarily for remote control access, the idea being that each of his family members would have a key fob remote to open it. There’s an input panel under the lid in case someone loses or forgets their remote.
The setup is simple. That 12V solar panel under the address number is connected to a solar charge controller and charges a small battery. Pushing the A button on the key fob remote triggers the latch to slide over, unlocking the door. A push of the B button turns on an interior light for late-night mail collecting. The tube on the side is for leaflets and other postal miscellany. Now, the coolest feature: when mail passes through the slot, it lets [George] know by calling his cell phone. Check out the build/demo video after the break.
We’ve featured all kinds of mailboxen over the years. This wifi-enabled ‘box uses an Amazon Dash button and a Pi to play the AOL notification on the owner’s phone. The flag on this adorable mini mailbox goes up when there’s mail in the real one outside.
Continue reading “Building a Sturdy Remote Control Mailbox”
We love solar power. Not only is it environmentally friendly, but it’s relatively lightweight and involves fragile high technology. Just the sort of thing that we’d want to strap onto the wings of a large model aircraft.
Solar power on a remote-controlled plane would get you unlimited cruising range. Now, a normal land-and-swap-battery process might be good enough for some people, but judging from [Prometreus]’s YouTube channel, he’s a fan of long flights over the Alps, and of pushing long-distance FPV links to the breaking point. For him and his friends, the battery power is definitely the limiting factor in how far / long he can fly.
All of the information we have is in the video, but that’s plenty. [Prometreus] didn’t bother with maximum-power-point tracking, but instead wired up his solar cells to work just about right for the voltage of his batteries and the level of sun that he’s seeing. So it won’t work nearly as well on cloudy days. (Check out this MPPT build that was submitted for the Hackaday Prize.)
He could switch the solar cells in an out remotely, and it’s pretty gratifying to see the consumed current in the battery go down below zero. In the end, he lands with a full battery. How cool is that?
Continue reading “Solar FPV Plane Flies Forever”
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.
Continue reading “Third Person Driving IRL”
When the remote for your son’s RC car goes missing, what are you going to do? Throw away a perfectly good robot chassis? No, we wouldn’t either. And these days, with WiFi-enabled microcontroller boards so readily available, it’s almost easier to network the thing than it would be to re-establish radio control. So that’s just what [Stian Søreng] did.
Naturally, there’s an ESP8266 board at the heart of this hack, a WeMos D1 to be specific. [Stian] had played with cheap remote-controlled cars enough to be already familiar with the pinout of the RC IC, so he could simply hook up some GPIOs from the WeMos board to the pins and the brain transplant was complete.
On the software side, he implemented control over TCP by sending the characters “F”, “B”, “L”, or “R” to send the car forward, back, left, or right. Lowercase versions of the same letters turns that function off. He then wrote some client software in Qt that sends the right letters. He says that response time is around 150-250 ms, but that it works for his driving style — crashing. (We’d work on that.)
Anyway, it’s a fun and fairly quick project, and it re-uses something that was destined for the junk heap anyway, so it’s a strict win. The next steps are fairly open. With computer control of the car, he could do anything. What would you do next?
Thanks [Eyewind] for the tip!
[Michael Brumlow] found us and sent us a link. Within a few seconds, we were driving a webcam-enabled Nerf dart tank through his office and trying not to hit walls or get stepped on by his co-workers. Unfortunately, it was out of darts at the time, but you can find them all over the floor if you scout around.
All of the code details, including the link where you can test drive it yourself, are up on [Michael]’s GitHub. The brains are an Intel Edison board, and the brawns are supplied by an Arduino motor controller shield and (for the latest version) a chassis bought from China.
It runs fairly smoothly, considering the long round trip from [Michael]’s office in Texas, through wherever Amazon keeps their Web Services, over to us in Germany and back. Once we got used to the slight lag, and started using the keyboard’s arrow keys for control, we were driving around like a pro.
It’s got a few glitches still, like the camera periodically overheating and running out of WiFi distance. [Michael] said he’d try to keep it charged up and running while you give it a shot. The controls are multiplexed in the cloud, so your chance of steering it is as good as anyone else’s. It’ll be interesting to see what happens when thousands of Hackaday readers try to control it at once!
It takes a certain kind of bravery to put your telepresence robot up on the open Internets. So kudos to you, [Michael], and we hope that you manage to get some work done this week, even though you will have all of Hackaday driving into your cubicle walls.