No Computer Ambilight Clone Uses A Computer

August 5, 2013 by 37 Comments

It may seem confusing that you’re looking at a Raspberry Pi when this hack is about an Ambilight clone system that doesn’t need a computer. The point here is that this system works no matter what your video source is, where many projects in the past have required the video to be playing from a computer.

This hack follows in the same path of the ARM based custom job we was almost a month ago. Just like that project you use an HDMI splitter to gain access to the feed going to your television. The split signal is fed into an HDMI to composite video adapter. The composite signal is captured by a USB video encoder. The GPIO header drives a strip of addressable RGB LEDs. The whole thing is powered as one using a bit of cable hacking.

It’s slightly convoluted. But all of the components are easy to source and relatively cheap. The one caveat is that it works best if you are already using a hardware HDMI source selector instead of the one build into your TV. That way there is just one HDMI cable going to the television, and this can siphon off of that feed.

Continue reading “No Computer Ambilight Clone Uses A Computer” →

Overclocking Your Bitcoin Miner

August 5, 2013 by 38 Comments

The name of the game in mining Bitcoins isn’t CPUs, GPUs, or even FPGAs. Now, hardcore miners are moving on to custom ASIC chips like the Block Erupter, For around $100 USD, you too can mine Bitcoins at 300 MH/s with 2.5 Watts of power and a single USB port. This speed isn’t enough for some people, like [Jeremy] who overclocked his Block Erupter to nearly twice the speed.

[Jeremy] begins his tutorial with a teardown of the Block Erupter hardware. Inside, he found a custom ASIC chip, an ATTIny2313, a USB UART converter, and a voltage regulator for the ASIC. By changing out the 12 MHz crystal connected to the ASIC and fiddling with the voltage with a trim pot, [Jeremy] was able to overclock the ASIC core from 336 MHz to 560 MHz. Effectively, he’s running two Block Eruptors for the price of one with the potential to actually make back the purchase price of his hardware.

It must be noted the 560 MHz figure comes from replacing the 12 MHz crystal with a 20 MHz one, and this mod only lasted about 20 minutes on [Jeremy]’s bench until the magic blue smoke was released. He recommends a 14 or 16 MHz crystal, netting a new speed of either 392 MHz or 448 MHz for a stable mod.

Android Hack Adds Missing Chromecast Button To Netflix App

August 5, 2013 by 7 Comments

We finally got our hands on a Chromecast over the weekend and we love it! But it wasn’t without a bit of a speed bump. Including a quick initial setup, we had a YouTube video playing in our living room about three minutes after the package hit our mailbox. But we spent the next twenty minutes feeling like a moron because we couldn’t get the Netflix app on an Android phone to cast the video. Turns out there is a bug in the Netflix app that doesn’t add the Chromecast icon for all devices.

The issue is that the newest version of the Netflix app isn’t pushed to all devices. A fix is on the way, but we’re not good at waiting. We used this technique to trick Netflix into thinking we have different hardware. Notice from the screenshots above that one lists our device as an LG-P769 manufactured by LGE. That’s how our /system/build.prop file originally looked. By using the BuildProp Editor app we changed those settings to Nexus S by samsung. After rebooting several of our apps were missing from the app drawer, including Netflix. But they all still worked hitting the Play Store for reinstallation and we now have no problem casting Netflix.

Hackaday Links: Sunday, August 4th, 2013

August 4, 2013 by 13 Comments

hackaday-links-chain

[Craig Turner] shows that simplicity can be surprisingly interesting. He connected up different colors of blinking LEDs in a grid. There’s no controller, but the startup voltage differences between colors make for some neat patterns with zero effort.

Remember the 3D printed gun? How about a 3D printed rifle! [Thanks Anonymous via Reason]

While we’re on the topic of 3D printing, here’s a design to straighten out your filament.

It takes four really big propellers to get an ostrich off the ground. This quadcopter’s a bit too feathery for us, but we still couldn’t stop laughing.

This Kinect sign language translator looks pretty amazing. It puts the Kinect on a motorized gimbal so that it can better follow the signer. We just had a bit of trouble with translation since the sound and text are both in Hebrew. This probably should have been a standalone feature otherwise.

Work smarter, not harder with this internal combustion wheelbarrow. [via Adafruit]

LED Strip Cape Drives Kilometers Worth Of LEDs

August 4, 2013 by 23 Comments

led-strip-cape

[Hudson] is looking to drive a lot of LEDs. A driver that effectively addresses kilometers worth of LED strips isn’t an easy thing to come by. So he’s in the process of designing his own BeagleBone Cape to do the work. Above you can see the board layout he’s working with. Notice the set of repeating red footprints in the center? Those are pads for 32 RS485 connectors!

Of course this is all in preparation for Burning Man where the mantra seems to be: he who has the most LEDs wins. Well, unless you’re the sort that likes to work with flames. But we digress. The scaling problem that [Hudson] is dealing with hinges around his desire not to include ridiculous numbers microcontrollers and the need to beef up the 3.3V logic levels of the BeagleBone to travel further on the data bus of the strips. By leveraging the RS485 protocol — which is designed to carry data over long distances — he can get away with a single processing unit by adding an RS485 translator at each remote strip connector. He plans to use the BeagleBone’s Programmable Realtime Units feature to address the eight drivers on the cape. But first he has to solve what looks like a doozy of a trace routing problem

Measuring Tiny Current With High Resolution

August 4, 2013 by 27 Comments

measuring-microamps-at-3MHz

[Paul] knew that he could get an oscilloscope that would measure the microamp signals with the kind of resolution he was after, but it would cost him a bundle. But he has some idea of how that high-end equipment does things, and so he just built this circuit to feed precision data to his own bench equipment.

He’s trying to visualize what’s going on with the current draw of a microcontroller at various points in its operation. He figures 5 mA at 2.5 mV is in the ballpark of what he’s probing. Measurements this small have problems with noise. The solution is the chip on the green breakout board. It’s not exactly priced to move, costing about $20 in single quantity. But when paired with a quality power supply it gets the job done. The AD8428 is an ultra-low-noise amplifier which has way more than the accuracy he needs and outputs a bandwidth of 3.5 MHz. Now the cost seems worth it.

The oscilloscope screenshot in [Paul’s] post is really impressive. Using two 1 Ohm resistors in parallel on the microcontroller’s power line he’s able to monitor the chip in slow startup mode. It begins at 120 microamps and the graph captures the point at which the oscillator starts running and when the system clock is connected to it.