Hackaday Links March 8th, 2012

March 8, 2012 By Leave a Comment

Solder Your Pin headers Straight

straight-header solder

If you’re worried about how to solder your pin headers straight, why not try this simple trick and put them into a breadboard before soldering?

Etiquette for Open Source Projects

soapbox Phillip Torrone

If you use or develop open source projects, it’s worth checking out [Phillip Torrone]’s Unspoken rules of Open Source article. You may not HAVE to do all the things he says, but it’s certainly a good starting point for being ethical with your hacks.

The [GoAmateur] Camera Mount

go-amateur camera mount for bike

If you can’t afford a professional camera mount for your bike, why not make one yourself? As pointed out in the article, normal cameras aren’t really made for this, so do so at your own risk. If this isn’t shoddy enough for you, why not make a mount for your 4 year old dumb-phone (Env2) out of a block of wood?

A 3D Printer BOM

If you’re wondering how much a 3D printer will cost you, or where to source the parts, this Bill of Materials for a Prusa Mendel should help. We would assume this project will be updated as everything is built, so be sure to check back!

MakerBot Assembly Time-Lapse

makerbot time lapse

Along the same lines, if you’re wondering about getting into 3D printing, this time-lapse of the Thing-O-Matic being assembled may give you some insight into what’s involved in getting one functional!

Filed Under: Hackaday links, news Tagged With: , , , , , , ,

Toaster oven reflow soldering roundup

March 8, 2012 By Leave a Comment

SMD components have a lot of advantages over the through-hole parts our fathers and grandfathers soldered. Working with these tiny surface mount components requires a larger investment than a soldering iron and a wire-wrap gun, though. Here’s a few reflow ovens that were sent in over the past week or two.

[ramsay] bought a 110 V toaster oven off of eBay. Even though [ramsay] is in England and has 230 V mains, everything in the oven is mechanical and works just fine with a higher voltage. His first test didn’t go quite as planned; the solder paste wasn’t melting at 120° C, so he cranked up the temperature and learned that the FR in FR-4 stands for flame retardant. Never deterred, [ramsay] decided to build a controller so the temperature ramps up and cools off at the right rates for the flux and paste to do their thing.

Solder paste has a temperature profile that requires the board to be kept at a temperature between 150° and 180° C for a minute or so before climbing up to 220° for a second so the solder will melt. [Nicolas] had the interesting idea of putting a USB port in his toaster oven and storing the heating profiles on his desktop. The build uses an MSP430 microcontroller to turn the relays powering heating elements on and off. [Nick] is working on a C# desktop app to monitor and regulate the oven temperature from his computer, so we’re fairly interested in seeing the final results.

Watching the SMD self-alignment videos on YouTube is a lot more fun than messing around with tweezers, stereo microscopes, and extremely fine soldering irons. If you’ve got a better idea for a toaster/reflow oven, send it in on our tip line and we’ll check it out.

Filed Under: tool hacks Tagged With: , , ,

Glove-based touch screen from a CRT monitor

March 7, 2012 By Leave a Comment

Here’s a bulky old CRT monitor used as a touch-screen without any alterations. It doesn’t use an overlay, but instead detects position using phototransistors in the fingertips of a glove.

Most LCD-based touch screens use some type overlay, like these resistive sensors. But cathode-ray-tube monitors function in a fundamentally different way from LCD screens, using an electron gun and ring of magnets to direct a beam across the screen. The inside of the screen is coated with phosphors which glow when excited by electrons. This project harness that property, using a photo transistor in both the pointer and middle finger of the glove. An FPGA drives the monitor and reads from the sensors. It can extrapolate the position of the phototransistors on the display based on the passing electron beam, and use that as cursor data.

Check out the video after the break to see this in action. It’s fairy accurate, but we’re sure the system can be tightened up a bit from this first prototype. There developers also mention that the system has a bit of trouble with darker shades.

[Read more…]

Filed Under: multitouch hacks Tagged With: , , ,

$10 camera module for your next FPGA project

March 7, 2012 By Leave a Comment

Here is [Voelker] showing off his FPGA-based camera hardware. He picked up an ov7670 camera on eBay for about $10 and set to work pulling pixels and processing the images. He’s now able to grab thirty frames per second and push them to his own Java display application. He’s using the Papilio board and if you want to give this a try yourself you might be able to snag a free breakout board (wing) for the unit.

[Voelker’s] approach is to grab each frame, and get it ready for quick serial transmission. The incoming frames are at 640×480 resolution. He scales that down to 80×60 and transmitted at 3M baud. The hardware resources used are actually quite light-weight. He wrote his own modules for transfer and photo processing using very little RAM for downscaling and one 128 byte buffer for data transmission. It sounds like he plans to use the camera to view and detect a line to create his own line-following robot.

Wondering where you’ve seen the ov7670 module before? It’s the part used on the TRAKR robot.

Filed Under: Microcontrollers Tagged With: , , ,

CAN bus for home automation

March 7, 2012 By Leave a Comment

Here’s one node on the new home automation system on which [Black Rynius] is working. So far he’s testing out the system with just two nodes, but plans to build more as the project progresses. He’s chosen to use the CAN bus for communications; a protocol which is most commonly found in automotive applications.

The biggest plus about using the CAN bus is that it requires just one pair of wires for communications. As you can see, there’s an old doorbell included on this board and he’s hoping to use the existing doorbell wire to connect between nodes. Each unit includes a PIC 18F4580 which has a CAN engine built into it for easy protocol translation. There is also an MCP2551 which handles the transmissions. You can read a bit more about the hardware choices in his breadboarding post.

So far almost everything is working as planned. He’s able to send and receive data between the two boards including temperature from a sensor and time from a DS1305 RTC chip. The one thing that vexes him is that doorbell. It draws too much current for the wall wart that’s powering the board, browning out the microcontroller and causing a reset. That’s not a hard fix and we look forward to more developments in the near future.

[via Dangerous Prototypes]

Filed Under: home hacks Tagged With: , , ,

Short and squat balancing bot is extremely stable

March 7, 2012 By Leave a Comment

[Lauszus] really put together an impressive self balancing robot platform. It is virtually motionless when balancing in place, and that stability is never lost even when motoring across the room.

Part of the success behind this build is the use of quality components. He’s got a really nice set of motors with built-in encoders which give feedback to the balancing system. They work in conjunction with a gyroscopic sensor and PID code to keep the two-wheeled platform upright. An mbed board running 96 MHz provides plenty of computing power for the balancing system. But an Arduino can also be found on board. This was included to facilitate Bluetooth connectivity with the remote control as [Lauszus] didn’t want to port the code he had already written.

The fourteen minute video after the break shares the details behind how the PID controller is tuned and how [Lauszus] implements target angle and a few other factors. Of course he talks about the hardware choices, and demonstrates functionality by driving the bot around using a wireless PS3 controller.

The construction method which uses masonite strips and threaded rod does a good job of protecting the hardware mounted on it. We’re always a bit worried about these bots falling over and some of the projects we see offer little or no protection. Once thing that helps protect against a spill is a piezo buzzer which sounds when the battery is getting low.

[Read more…]

Filed Under: robots hacks Tagged With: , , , , , ,
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