[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.

RF Switching Module Can Learn New Remotes

February 20, 2013 by Mike Szczys 12 Comments

rf-remote-also-learns-by-itself

This breadboarded circuit is [Sergio’s] solution to controlling appliances wirelessly. Specifically he wanted a way to turn his pool pump on and off from inside the house. Since he had most of the parts on hand he decided to build a solution himself. What he ended up with is an RF base station that can learn to take commands from different remote devices.

The main components include the solid state relay at the bottom of the image. This lets the ATtiny13 switch mains voltage appliances. The microcontroller (on the copper clad square at the center of the breadboard) interfaces with the green radio frequency board to its left. On the right is a single leaf switch. This acts as the input. A quick click will toggle the relay, but a three-second press puts the device in learning mode. [Sergio] can then press a button on an RF remote and the device will store the received code in EEPROM. As you can see in the clip after the break, he even included a way to forget a remote code.

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Wireless Light Bulbs With A Slayer Exciter

February 13, 2013 by Brian Benchoff 18 Comments

slayer rocks While playing chiptunes, creating lightning, and illuminating fluorescent tubes with a homebrew Tesla coil is awesome, they’re not exactly the safest electrical devices around, and certainly aren’t easy or cheap to build. There’s another option open if you’d like to play with strong electromagnetic fields; it’s called the Slayer exciter and is simple enough to light a few fluorescent bulbs wirelessly off a pair of 9 Volt batteries.

The circuit for the Slayer exciter is extremely simple – just a single power transistor, a few diodes, and a couple of resistors. The real power for this build comes from the custom-wound transformer made from more than 100 feet of magnet wire. After plugging the driver circuit into the transformer’s primary winding and connecting a metal ball (in this case a wooden ball covered in aluminum foil), it’s possible to light up a four Watt fluorescent tube with a pair of 9 Volts.

You can check out a video of the Slayer exciter after the break.

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Pinoccio Web Rover

February 9, 2013 by Jeremy Cook 7 Comments

Before assuming that the title should be “web crawler,” just shush your shussins’ and check out the video after the break. The Pinoccio, as previously noted, is a board in development as a sort of web-enabled by default Arduino. This makes it perfect for a project like this one where a little rover is controlled from 10,000 Kilometers away, or around 6000 Miles for those of us that dwell in the US.

This setup uses a cell-phone accelerometer in Brazil to allow control of this robot in Nevada. Although close, the control isn’t quite real time, so that has to be accounted for. Something like this could be easily used for a telepresence ‘bot.

If you want to build your own, the assembly time is estimated at 1 hour. Instructions, as well as source code can be found on their page after the video. Although the Pinoccio board won’t be available until at least this summer, maybe this will give someone inspiration to try something similar in the mean time! Continue reading “Pinoccio Web Rover” →