[Travis Goodspeed] and Hackaday alum [Fabienne Serriere] joined forces to develop an alternative interface for a knitting machine. They’re working with the Brother KH-930E machine. We saw [Becky Stern] use the same model by manipulating data on an emulated floppy drive for the device. [Travis] and [Fabienne] went a different route, and are emulating the keypad using an Arduino and a set of transistors.
They started by reverse engineering the keypad matrix using a continuity tester. Once they worked out the column and row layout they connected each to an NPN transistor. The Arduino sketch simulates button presses to set knitting bits for each row, with just one reset button for user input. This can be used to send data from a PC, or as a standalone system. Either way, it’s not only a great way to add functionality to the kitting machine, but a good example of how to interface with the keypad on just about any device.
[Thomas Cannon] created his own hacking game by adding some circuitry to this toy vault. The original toy uses the keypad to control a solenoid keeping the door shut. He kept the mechanical setup, but replaced the original circuit board with his own ATmega328 based internals. He also added a USB port to the front. The gist of the game is that you plug-in through USB to gain access to the vault’s terminal software. If you can make your way through the various levels of admin access the loot inside will be yours.
This programmable power supply is the perfect addition to your bench tools. [Debraj Deb], who previously built a whole house power monitor, designed this build around a PIC 18F4520 microcontroller. The desired voltage is set with an attached keypad, resulting in a digital output on the 8-bits of port D. The port connects to another protoboard with an R-2R digital-to-analog converter resulting in the target voltage. A set of transistors amplifies the current and a power transistor then takes care of the final output. After the break you’ll find two videos, the first walks us through the hardware and the second demonstrates the device in action, along with measurements of its performance. This certainly provides a lot more functionality than an ATX power-supply conversion.
Update: A big thanks to [Debraj] who sent us a code package as well as the schematic (PDF) used during testing. We’re having trouble getting the code package up for download right now. Check back later, hopefully we’ll have it up soon.
Continue reading “PIC programmable power supply”
[Dan McGrath] tipped us off about a solution for a problem that most people don’t have. He built a web-based entry system for his garden gate. This isn’t quite as original as that chain and sprocket dorm room system, but it does use a keypad for entry. [Dan’s] already got a web server and home automation box that is always running. He coded a webpage that presents a virtual keypad for code entry. If the right code is input the system unlocks the electronic strike on the other side of this gate. Since the interface is a web page you can load if from any web browser (an iPhone is used for demonstration purposes after the break). But if you don’t have internet access you’re in trouble; there’s no physical keypad. But we guess you could always just jump the fence. Continue reading “Automated entry for a garden gate”
It’s that time of the year again. The leaves are changing colors, it’s getting colder outside, and all the littler hackers are off to college. Which means we get to see an influx of dorm room locks and openers.
[Adam] is back at it again with a new keypad dorm room lock. Last year he had an exceptional setup using a car keyfob, so we’re a little curious as to why he would revert to such a low level system as a keypad that isn’t even color coded.
Perhaps its in his “new” way of presenting the hack. Rather than a blog or write up, he documents the entire most of the process in a little less than 20 YouTube videos. Watch him testing out the system after the jump.
Continue reading “Keypad door lock, better than last years keyfob?”
Our friend [Sprite_TM] took a look at the security of a code-protected hard disk. The iStorage diskGenie is an encrypted USB hard drive that has a keypad for passcode entry. After cracking it open he found that the chip handling the keypad is a PIC 16F883 microcontroller. He poked and prodded at the internals and found some interesting stuff. Like the fact that there is an onboard LED that blinks differently based on the code entered; one way for the right code, another for the wrong code of the right number of digits, and a third for a wrong code with the wrong number of digits. This signal could be patched into for a brute force attacking but there’s a faster way. The microcontroller checks for the correct code one digit at a time. So by measuring the response time of the chip an attacker can determine when the leading digit is correct, and reduce the time needed to crack the code. There is brute force protection that watches for multiple incorrect passwords but [Sprite_TM] even found a way around that. He attached an AVR chip to monitor the PIC response time. If it was taking longer than it should for a correct password the AVR resets the PIC before it can write incorrect attempt data to its EEPROM. This can be a slow process, but he concluded it should work. We had fun watching the Flash_Destroyer hammer away and we’d like to see a setup working to acquire the the code from this device.
Here’s two input devices you can easily build with materials you already have on hand.
To the left, [John] built a 3×3 keypad matrix from paper and tinfoil. The rows and columns are made up of strips of tin foil on the front and back layers of paper. The layers are separated by spongy double-stick tape. A ‘keypress’ results when the gap between the conductors is compressed with your finger.
In much the same way, [Dave Fletcher] built a touch potentiometer. He made two resistance plates by scribbling pencil lead on sheets of paper. When the two plates face each other, separated by the same type of foam tape as before, they can be pressed together to form a circuit with a variable resistance. This results in a crude version of the SparkFun softpot.