A Modular 1GHz Spectrum Analyzer

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[MrCircuitMatt] has been doing a lot of radio repair recently, quickly realized having a spectrum analyzer would be a useful thing to have. Why buy one when you can build one, he thought, and he quickly began brushing up on his RF and planning out the design of a 1000 MHz spectrum analyzer

The project is based on Scotty’s Spectrum Analyzer, a sweep-mode, modular 1GHz spectrum analyzer that is, unfortunately, designed entirely in ExpressPCB. [Matt] didn’t like this proprietary design software tied to a single board house. The basic building blocks of [Scotty]’s spectrum analyzer were transferred over to KiCAD, the boards sent off to a normal, Chinese board house.

In the second video, [Matt] goes over the design of the control board, a small module that connects the spectrum analyzer to the parallel port of a PC. There’s a lot of well thought out design in this small board, a good thing, too, since he’s powering his VCO with a switched mode supply. The control board has a 32-bit I/O, so how’s he doing that with a parallel port, what is ultimately an 8-bit port? A quartet of 74ACT573, a quad buffer with latch enable. Using the eight data lines on the parallel port allows him to toggle some pins while the ancient pins on the parallel bus – Strobe, Select Printer, and Line Feed control the latches on each of the buffers. This gives him the ability to write to 32 different pins in his spectrum analyzer with a parallel port.

Right now, [Matt] is wrapping up the construction of his control board, with the rest of the modules following shortly. He thinks the completed analyzer might even be cheaper than a professional, commercial offering, and we can’t wait to see another update video.

Continue reading “A Modular 1GHz Spectrum Analyzer”

Electronic Puzzle Box Uses Only Discrete Components

Puzzle box

Do you need an idea for a fun do it yourself gift for a friend or significant other? Look no further, [conductance] has you covered. He put together an awesome electronic puzzle box using all analog electronics. The puzzle case is shaped like an over sized die and is made out of wood. It also requires a small jumper cable and an external magnet to complete the puzzle.

This is a six-sided die, where each side has something different to offer. The “five” side of the die shows the progress you’ve made in completing the puzzle. Each of the five dots contains a green LED that will light up when the corresponding puzzle has been successfully completed.

The “one” side is completed by placing the included magnet over the dot. The magnet activates a reed switch which lights up the first LED. The “two” side contains a tilt switch. In order to solve this piece of the puzzle you must ensure the two side is facing up, as if you rolled a two. The “three” side contains three key switches. Each switch must be turned to a particular orientation. Once all three keys are configured properly, a third LED lights up.

The “four” side contains four sockets that fit the included jumper cable. This puzzle is solved by jumping the two correct sockets together. Finally, the number “six” side just has six momentary push buttons. All six buttons must be pressed simultaneously in order to light up the final LED. The tricky part is pressing all six buttons while simultaneously “rolling” a two in order to ensure the tilt switch is also activated.

Once all five LED’s are lit up, a relay is triggered which then activates a solenoid. The solenoid unlocks the door and reveals the prize. It’s always great to see electronics circuits like this that use all discrete components. This could have been accomplished any number of ways, but there’s something satisfying about a simple circuit that’s just right for the job. Be sure to check out [conductance’s] schematic if you want to see how this puzzle works.

[via Reddit]

Thumbnail that say The Hacklet

The Hacklet #3

The Hacklet Issue 3

The third issue of The Hacklet has been released. In this issue, we start off with a roundup on the Sci-Fi Contest which recently concluded. After seeing the many great hacks you came up with for that contest, we’re looking forward to seeing what you think of for The Hackaday Prize.

Next up, we take a look at two hacks that deal with switching mains, which is a feature that most home automation projects need. These high voltage switches can be dangerous to build, but one hack finds a safe and cheap way to do it. The next looks at building your own high voltage circuitry.

Finally, we talk about two laser hacks. The first is practical: a device for exposing resins and masks using a laser. The second is just a really big laser, built from hardware store parts. Who doesn’t like big lasers? We definitely like big lasers, and so does the FAA.

Metal Inlays Using A Bit Of Solder

metal inlay

Looking for a unique way to add a nice metal inlay to finish off your project? [Ben Krasnow] shows us how using a CNC router, a bit of solder, and a lot of sand paper!

It’s actually a pretty simple job — Of course, that’s only if you have a CNC machine. [Ben] started by engraving his inlay using his handy CNC mill, and then sanding off any rough spots. He then filled the engraving with acid flux paste, got out his MAPP gas torch and started dripping solder into the piece. Once everything was covered, he started sanding it, from 60 grit all the way to 600 grit for a nice polished finish. The results speak for themselves.

An easier method of this could also be achieved using plastic and epoxy, instead of brass and solder. One of the biggest problems with the solder is bubbling, which can cause voids which will appear when you are sanding — so you might have to do a second pass with the solder.

[Ben Krasnow] is an interesting character. He’s sought out the perfect cookie, made his own CT scanner at home, explained the various heat treatments of steel — and even installed LEDs into his contact lenses just for kicks!

[Thanks Fabien!]

LED IM status indicator

Green Light Go, Red Light Come Back Later

Depending on your taste for social interaction and tolerance for distraction, an open floor plan or “bullpen” office might not be so bad with a total of four people. Hackaday.io user [fiddlythings] likes it, but people often stop by to see him or one of his coworkers only to find them busy or absent. While their status is something they could plainly see in Microsoft Communicator from their own desk, some people like to chat in person or stop by on their way to and from meetings.

In order to save these visitors a few seconds, [fiddlythings] came up with an IM status indicator using their existing nameplates outside the door. Each of their names has a little silver dot by it which he backlit with a flattish RGB LED. These LEDs are driven by a Raspberry Pi and NPN transistors through a ribbon cable.

The plan was to imitate the Communicator status colors of green for available, red for busy, and yellow for away. [fiddlythings] dialed up a lovely shade of amber for away using a mix of red and green. Since he really only needs two colors, he’s using eight NPN transistors instead of twelve. The quick ‘n dirty proof of concept version used Python and a Pidgin IM console client called Finch. Once he got IT’s blessing, he implemented the final version in C++ using Libpurple to interface with Communicator.

This isn’t the first time we’ve seen a Pi used to indicate status—remember this mobile hackerspace indicator?

Samsung NX300 Gets Rooted

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[Ge0rg] got himself a fancy new Samsung NX300 mirrorless camera. Many of us would just take some pretty pictures, but not [Ge0rg], he wanted to see what made his camera tick. Instead of busting out the screwdrivers, he started by testing his camera’s security features.

The NX300 is sold as a “smart camera” with NFC and WiFi connectivity. The NFC connectivity turns out to be just an NXP NTAG203 tag embedded somewhere in the camera. This is similar to the NFC tags we gave away at The Gathering in LA. The tag is designed to launch an android app on a well equipped smartphone. The tag can be write-locked, but Samsung didn’t set the lock bit. This means you can reprogram and permanently lock the tag as a link to your favorite website.

[Ge0rg] moved on to the main event, the NX300’s WiFi interface. A port scan revealed the camera is running an unprotected X server and Enlightenment. Let that sink in for a second. The open X server means that an attacker can spoof keystrokes, push images, and point applications to the camera’s screen.

In a second blog post, [Ge0rg] tackled attaining root access on the camera. Based on the information he had already uncovered, [Ge0rg] knew the camera was running Linux. Visiting Samsung’s open source software center to download the open source portions of the NX300 confirmed that. After quite a bit of digging and several red herrings, [Ge0rg] found what he was looking for. The camera would always attempt to run an autoexec.sh from the SD Card’s root folder at boot. [Ge0rg] gave the camera the script it was looking for, and populated it with commands to run BusyBox’s telnet daemon.  That’s all it took – root shell access was his.

 

[Image via Wikimedia Commons/Danrok]

Upgrade Your Garage Door With Arduino And RFID

RFID Garage Door Opener

[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”