[Jason] really wanted to build an RFID controlled garage door opener and decided to turn to Arduino to get the job done. For someone who’s never worked with an Arduino before, he really seemed to know what he was doing.
The Arduino acts as the brains of the operation while an off-the-shelf NFC/RFID reader module is used to read the RFID tags. To add new keys to the system, [Jason] simply swipes his “master” RFID key. An indicator LED lights up and a piezo speaker beeps, letting you know that the system is ready to read a new key. Once the new key is read, the address is stored on an EEPROM. From that point forward the new key is permitted to activate the system.
Whenever a valid key is swiped, the Arduino triggers a relay which can then be used to control just about anything. In this case, [Jason] plans to use it to control his garage door. The system also has a few manual controls. First is the reset button. If this button is held down for two seconds, all of the keys from the EEPROM are erased. This button would obviously only be available to people who are already inside the garage. There is also a DIP switch that allows the user to select how long the relay circuit should remain open. This is configurable in increments of 100ms.
For now the circuit is wired up on a couple of breadboards, but it might be a good idea to use something more permanent. [Jason] could always take it a step further and learn to etch his own PCB’s. Or he could even design a board in Eagle CAD and order a real printed board. Don’t miss the video description of the RFID system below. Continue reading “Upgrade Your Garage Door with Arduino and RFID”
Here’s something we’re sure SEO specialists, PR reps, and other marketeers already know: how to write a script to game reddit.
The course of upvotes and downvotes controls which submission makes it to the front page of reddit. These submissions are voted on by users, and new accounts must log in and complete a CAPTCHA to vote. [Ian] discovered that reddit’s CAPTCHA is not really state-of-the-art, and figured out how to get a bot to solve it
The method exploits the 8-bit nature of the distorted grid in the CAPTCHA. Because this grid isn’t pure black or pure white, it’s at a lower intensity than the letters in the CAPTCHA. Putting the CAPTCHA through a threshold filter, deleting any blocks of pixels smaller than 20 pixels, and running it through a classifier (PDF there), a bot can guess what the letters of the CAPTCHA should be.
Out of the 489 CAPTCHAs [Ian] fed into his algorithm, only 28 – or 5.73% – were guessed correctly. However, because he knows which CAPTCHAs had failed segmentation, ignoring those can increase the success rate to 10%. Theoretically, by requesting new CAPTCHAs, [Ian] can get the accuracy of his CAPTCHA bot up to about 30%.
Combine this with a brilliant auto voting script that only requires someone to enter CAPTCHAs, and you’ve got the recipe for getting anything you want directly to the front page of reddit. Of course you could do the same with a few memes and pictures of cats, but you knew that already.
[Will] likes Reddit so much he built this dedicated controller that lets him play the social website like a video game.
He calls it he Karma Controller. In this case, ‘Karma’ refers to ability to accumulate a large number of net up-votes on a Reddit post. The device features seven buttons which are all it takes to up and down vote, navigate up and down on the Reddit listings, toggle images, as well as open and close new tabs for the comments section. We’re wondering if it allows you to follow a link to the post source too?
One of the reasons that we’re featuring this is that it’s only [Will’s] second electronics project. If you’re still reluctant to get your hands dirty we hope this acts as inspiration. He started by building the first version on a hunk of protoboard. The Digispark microcontroller seen at the top reads from his button network and communicates with the computer via USB. Once the design was proven he had some help etching this circuit board which is version 2. He shows it off in the clip after the jump.
If you just want some buttons for voting you should take a look at this project which includes a 3D printed enclosure and button covers.
Continue reading “Karma Controller makes Reddit a game”
Our AMA is live right now. Come ask us questions. You can ask here in our comments too, but frankly the Reddit system is better for at length nested discussion.
Items to be discussed:
-how to submit your story to hackaday
-our new template coming soon
[Chris] has recently become a self-declared Reddit addict and wanted to build something that would streamline the process of voting on posts. Inspired by the Awesome Button hack featured on Make a little while back, he thought that a physical upvote/downvote button would be the ideal peripheral for all of his Reddit needs.
He was a big fan of using the Reddit Enhancement Suite, which allows you to submit votes with a single keystroke. He combined this browser extension with a Teensy development board, and had his voting button prototyped in no time. Once he fine-tuned the Arduino sketch that he used to emulate the required keypresses, he got busy building a case for his creation.
He busted out his 3D printer and had a custom working project box in about 30 minutes. He printed arrows for the upvote and downvote buttons, snapped everything together, and then gave his quick vote box a spin. Everything worked perfectly, and he’s quite happy with his creation.
We imagine that our resident Reddit addict in chief is pretty jealous right about now…
Stick around if you’d like to see a time lapse video of the button’s creation.
Continue reading “USB Reddit Upvote/Downvote button”
Like any other organization out there, we’re always trying to find new ways to reach our audience. Admittedly, we’re not the fastest when it comes to adopting a new social communication site. We’re working on it though, trying to be a bit more interactive … or just plain active.
So, if you’re looking for other ways to get your hacking fix, or see some interesting commentary, find us on facebook, twitter, our own forums, and now G+. We just signed up to G+ and our name is
“Hackie Smith”. If you need an invite, email us at email@example.com see below. Sometimes there’s good discussion in those places that doesn’t end up here on the site.
You can also find several of us spattered across the web in sites like Reddit and Slashdot.
[Update: Our g+ page got shut down. Feel free to find any of the writers on g+. I’ll give out invites, look for “Caleb Kraft” or 60mango@gmail]