Automatic volume control puts the kibosh on loud TV commercials

automatic-tv-volume-control

If you’re having a hard time tuning out those loud commercials why not let your electronics project do it for you? This is an Arduino-based setup which adjusts television volume when it goes above a certain threshold. It uses a microphone, rather than a direct audio signal, so you can set it based on what is actually heard in the room.

The control scheme uses the IR LED and IR receiver seen on the breadboarded circuit above. The receiver lets you teach your volume up and down buttons from your remote control to the system. The one failing we see in the design is that the volume level is hard-coded, requiring you to flash new code to make adjustments (perhaps an enterprising reader could add a potentiometer for making easy adjustments?).

We can’t help but be reminded of the setup which reads the closed caption info to mute topics you’ve added to a blacklist.

Adding remote control to Klipsch surround system

The speaker system [Zurcher] bought was made by Klipsch. It is a surround sound unit but it’s intended to be used with a computer so there’s no wireless remote for it. Instead, a wired unit sits on the desk and lets you select between the speakers or headphones, and has a volume adjustment knob. The thing is he uses them for his home theater system and had to add his own remote control hardware to adjust them from across the room.

He started with some web searches that helped a lot. It seems others have mapped out the hardware in the past and he was able to use that information to find the volume chip inside the controller. A bit of signal sniffing let him work out the control commands coming in over the i2c bus. This was the information he needed to build his own controller. He grabbed his Arduino board, and IR receiver to take commands from just about any remote, and a four-digit 7-segment display to provide settings feedback. You can seen him showing off the final build in the clip after the break.

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Microcontroller based audio volume level compressor

In an effort listen to his music on shuffle without the need to touch the volume knob [Mike] build his own automatic volume leveling hardware. He knows what you’re thinking right now: there’s software to do that for you. But building the feature in hardware is a great stepping off point for a project.

He started the prototype using LabVIEW along with a Mobile Studio development board and a Bus Pirate. This project will be a mix of digital and analog components and it’s a bit easier starting off the exploration with these tools rather than jumping right into the AVR code.

The circuit will sample the incoming audio, modify it accordingly, and output the result. The output side is where the Bus Pirate really shines. He’s using some MCP42010 digital potentiometer chips to make the necessary changes to the levels. They communicate via SPI and it’s nice to have the Bus Pirate’s terminal to issue commands without the need to reflash a microcontroller.

[Mike] made a video showing an audio waveform with and without the hardware leveling. Sound quality is still great, and each clip is played at a reasonably comfortable listening level. We’ve embedded that demonstration after the break.

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Keep all eyes on your kegerator with this light up gauge cluster

kegerator_gauge_cluster

A few years back [Evan] built a kegerator from a mini fridge and was quite happy with his new beer chiller. Like many of us do, he started thinking up ways in which he could improve the project as soon as it was completed. While it took a couple of years, he recently got around to adding the temperature and capacity gauges he always wanted.

He added a temperature probe to the refrigerator, and then constructed a pair of tools that he could use to measure how much beer was left in the keg. The volume monitors include a scale built using a pair of pressure sensors from SparkFun, and a flow sensor installed in the beer line.

[Evan] scored an old Chevy gauge cluster and cleaned it up before installing a pair of analog meters which he used to show the keg’s temperature and “fuel” level. Since he feels no project is complete without some LED love, he added a few of them to the display without hesitation. The LEDs calmly pulsate when the keg sits idle, but spring to life and begin flashing when the flow sensor is activated.

As evidenced by this pair of keg monitoring systems, we think that you can never have enough information when it comes to your beer stash, so we really like how this project came together.

Be sure to check out his kegerator’s gauge cluster in the video below.

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Vigorous exercise keeps the tunes coming

There are cars that increase the radio volume as you drive faster, and video games that ramp up the music as your gameplay improves (we’re looking at you SSX Tricky). Now you can add that feature to your workout with [Polymithic's] Motion Feedback MP3 Player. It uses a passive infrared sensor to detect motion so there’s no need to wear any electronics. But if you used some Bluetooth headphones you could bring the system with you to the gym, just don’t exercise so hard that you blow your eardrums out.

[via Hacked Gadgets]

Monitor Keg volume, CO2, and temp

[Jean-Michel] tipped us off about his beer keg monitoring setup. It can tell you how much beer is left in each keg, how much carbon dioxide remains in the canister, and it can monitor and regulate temperature.

An Arduino mega is the brain of the system. A shield was built to interface force sensors, measuring the weight of the keg to estimate how much beer remains. Analog temperature sensors allow for temperature monitoring and control of the compressor for regulation. Information can be displayed on a graphic LCD or a computer via XBee wireless communications.

This is along the lines of the SparkFun kegerator but we like the added functionality. Does this need to Twitter? Probably not but if you want that, it’s only a bit of a software hack away.

Parts: DS1801 SPI audio volume potentiometer

ds1801

Dallas/Maxim’s DS1801 is an audio volume potentiometer with a simple SPI interface. This chip has two channels of volume control that might be useful in a DIY audio project. We previously looked at the DS1807, a similar part with an I2C interface. This week we’ll show you how to use the SPI version.

[Read more...]

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