Wireless Microcontroller/PC Interface For $3

May 19, 2013 by Brian Benchoff 48 Comments

Sending data from a microcontroller to a PC usually requires some sort of serial connection, either through fiddly on-chip USB, FTDI chips, or expensive radio ICs. [Scott] didn’t want to deal with this when creating a network of wireless temperature sensors, so he hacked up a few cheap 433 MHz radio transmitters and receivers to transmit data to a PC for about $3.

After sensor data is collected on a microcontroller and sent over radio, there’s still the issue of getting it into a PC. For this, [Scott] piped the data into the microphone port of a cheap USB sound card. We’ve seen this trick before both in the world of microcontrollers and loading programs onto a Commodore 64 via a cassette interface.

Once the data is sent into the sound card, it’s decoded with a a small Python app. Given the range and quality of the RF transmitters and receivers [Scott] says it’s not an extremely reliable way to send data to a PC. It is cheap, though, and if you need to read sensors wirelessly on a budget, it’s hard to do much better.

Check out [Scott]’s demo of his creation below.

[youtube=http://www.youtube.com/watch?v=GJHFldPwZvM&w=580]

Wifi Pineapple Project Uses Updated Hardware For Man-in-the-middle Attacks

April 29, 2013 by Mike Szczys 38 Comments

We’ve seen this small, cheap, and powerful WiFi router before. But this time it’s up to no good. [Andy] used a TP-Link WR703N to build an upgraded WiFi Pineapple hacking tool.

A WiFi Pineapple is a device spawned years ago by the Hak5 team (here’s a clip showing off the device). It uses a WiFi router that will answer to any SSID request. Basically if your computer or smart phone has an AP SSID saved and broadcasts a request to connect the pineapple will pretend to be that device and start the handshake. This provides the chance to sniff all the data passing through in a classic man-in-the-middle attack.

[Andy] is recreating the device but at a rock bottom price. He picked up this router for about $20 and added an $8 USB drive to it. The only other thing you would need is a power source and a way to hide the hardware. The code used in the Hak5 version is available for download and that’s what he worked on after flashing OpenWrt to the device.

[Thanks Midnite]

Acrobatic Tricopter Inspired By The Oblivion Movie Trailer

April 24, 2013 by Mike Szczys 28 Comments

tricopter

There have been a ton of commercials for the new [Tom Cruise] movie called Oblivion. One of the main points in every clip we remember seeing is the Top Gun meets Star Trek vehicle he does some tricks in. [James Cotton] loved that footage and ended up building his own RC version of the vehicle.

Three propellers give it lift, with directional control facilitated by servo motors which can pivot the motors attached to the two orange propellers. This design produces remarkably responsive controls as shown in the video after the break. That being said it’s still not immune to operator error. At the end of the clip [James] crashes it hard, stripping out the gears on the servo motors.

He has a few things in mind for the future of the device (and he’ll have plenty of time to plan while he waits for replacement servos to arrive). The aircraft should be able to carry a camera long with it. He discusses the issues involved with where the camera ends up pointing based on what the tilting motors are doing. But we figure he could always build a base that lets the camera pan and tilt separately from the chassis.

You can find a few tricopter projects around here but we’ve always like the one made of cardboard.

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[FlorianH] Shows Off MinimaBL, The Next Generation Of His Quadcopter Project

April 15, 2013 by Mike Szczys 26 Comments

minimabl

[FlorianH] has all kinds of new features to show off with this generation of his quadcopter project. Just about everything has seen an upgrade or some other kind of tweak since we looked in on the last version of the aircraft.

You’ll find some outdoor flight demo clips after the break. Right off the bat we’re impressed at the rock solid stability of the quadrotor while in flight. Even indoors the last version had a hint of a wobble as the control loop calculated stabilization. Here he borrowed some code from the open source Aeroquad project which helps account for this improvement. But the hardware choices lend a hand too. He moved from an ATmega32 up to an STM32F405RG processor. That’s an ARM chip which he programs using one of STM’s Discovery boards. The motors have all been upgraded as well (if you listen in the demo videos for both models you can hear a difference) and he redesigned the frame, which combines carbon tube with 3D printed parts to keep it light yet strong. The upgrade is every bit as impressive as the original build!

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Upgrading A Router With Impeccable Soldering Skills

April 3, 2013 by Brian Benchoff 25 Comments

router

[Necromant] recently acquired a router that was nearly free. Looking his gift horse in the mouth, he hooked up a serial port to see if it could run some updated firmware such as OpenWRT. The initial findings were promising; it used the same CPU as the very popular WR703N, but this free router only had 2 MiB of Flash and 8 MiB of RAM – barely enough to do anything. His solution to this problem is in the true hacker tradition: just solder some more chips onto the router.

Upgrading the RAM was comparatively easy; [Necromant] found an old stick of RAM, desoldered one of the chips, and replaced the measly 8 MiB chip with a new 64 Megabyte chip.

The Flash, though, proved more difficult. Without the right code in the Flash for the radio test, the router wouldn’t be useful at all. The solution was to read the original 2 MiB chip, read the Flash from a WR703, and combined the two with a simple dd command. This was written to a new SPI flash chip with a buspirate and a home etched board.

Doctor Who-style WiFi

April 1, 2013 by Brian Benchoff 20 Comments

wifi

Spoilers, sweetie…

If you didn’t catch the latest episode of Doctor Who, here’s the plot: Random people connect to strangely-named WiFi networks and later have their conciousness uploaded to the Internet with the help of spoonheaded robots. To the non-Whovian that doesn’t make a whole lot of sense, but [Tony Box] figured out a way to replicate the effect with a Linux box and a USB WiFi card, just in time for a great April Fool’s gag.

For the SSID, the folks over on reddit decided the best characters come from the Unified Canadian Aboriginal Syllabics Unicode block. [Tony] then set up a laptop with a USB wifi card with hostapd, and dnsmasq to change the SSID and DHCP leases. nginx serves up a simple web page with a short clip from the episode (of a spoonhead uploading a conciousness).

Here’s what’s really interesting: [Tony] is using a captive portal, so something like the webpage that shows up when you log on to the internet in a coffee shop or hotel. When the victim of this prank logs on to The Great Intelligence’s WiFi, they’re presented with a webpage containing the video of the spoonhead.

You can check out [Tony]’s demo of his build after the break.

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Wireless Base Station Eavesdrops On Robot Communications

March 18, 2013 by Mike Szczys 6 Comments

wireless-base-station-evesdrops-on-robot-communications

The good [Doctor Iguana] has been working on a pair of robots which communicate with each other using mRF24J40MA wireless transceivers. This presents a challenge in debugging, as he really didn’t have an easy way of monitoring those communications. His solution was to build his own base station which lets him use a computer to monitor what each robot is saying.

He spun his own board for the project. USB connectivity is provided by an FTDI chip, the FT232RL. This converts the USB communications in to serial for the dsPIC33 microcontroller. The FTDI chip comes with a fairly fine-pitch, but the footprint can still be fabricated using toner transfer if you’re fairly familiar with the process. [Dr. Iguana] took some close-up images of the unpopulated board which might make you a little nervous with the soldering iron. The other end of the board hosts the same Microchip wireless module as he used in his robots.

After a bit of rework (noted on the photo labels) he got this up and running. Now he can capture all of the wireless communications and see if problems are due to the sender or the receiver.