Add external power to any USB hub

usb-hub-psu

[Andrew] was getting some poor performance from a couple of USB devices he had connected through an unpowered hub. This is a problem because the hub prevents devices from negotiating with the host controller for more current. He fixed it by adding an external power supply to his USB hub.

In this case the PCB already had a footprint for a power connector. The manufacturer uses one board for several different models and just leaves the supply components unpopulated. [Andrew] managed to find a barrel jack in his parts bin that matched the footprint.

One important thing to do before hooking up the source is to disconnect the 5v wire from the incoming cable from the computer. The other tip we can give you is to use a good regulated 5v source to ensure you don’t damage the stuff you’re trying to power. That means avoiding deals that are too good to be true.

Alert Tube monitors all aspects of your digital life

alert-tube

This futuristic appliance can keep you apprised of all you social network goings on and much more. [Mike Watson] calls the device the Alert Tube because of its functionality and shape. The hardware depends primarily on a Raspberry Pi board which seems tailor-made for this type of use. The information gathering side of this shows off the power of a fledgling services called If This Then That.

We’ve heard of IFTTT only because [Chris Gammel] and [Dave Jones] covered it on an episode of The Amp Hour. [Dave] dismissed it as have little to no practical use. But this project shows how it can be leveraged to make quick work of pulling your desired data from the Internet. Think of it as a collection of APIs for many sites like Twitter, Facebook, as well as local weather, etc. This project sets up IFTTT to monitor your accounts, alerting you with colors of like, sound, and even text-to-speech.

The project explanation is several pages long but you can get a quick look at it by watching the demo video.
[Read more...]

Use your ears as an oscilloscope

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When work on an engine control circuit [Scott] found himself in need of a way to compare the performance of two control circuits at once. The hobby quality oscilloscope he owns wasn’t up to the task. After thinking about it for a bit he ended up using his ears as the oscilloscope.

The signals he was measuring are well suited for the challenge as they fell within the human range of hearing. He used some wire wrapped around each of the three conductors on the jack of his headphones in order to connect them to a breadboard. Then he simply connected each channel to one of the motor driver circuits, and connected the common ground. Listening to the intonation of the pitches in each ear he was literally able to tune them up.

If he had been looking for a specific frequency he could have used his sound card to take and analyze a sample. But balance was what he needed here and you must admit that this was an easy and clever way to get it!

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