Noise Pollution Tit For Tat Uses The Baha Boys As A Weapon

July 3, 2012 by Mike Szczys 88 Comments

Here [Matthew Br] explains the situation he’s in with the neighbors that share this wall of his apartment. When they listen to music they like it loud and so he gets to ‘enjoy’ the experience as well. But he can’t ignore it any longer, and has decided to use a sound volume detector to blast some tunes right back at them.

He taped a microphone to the wall and wired it up to his Arduino. It monitors incoming sound and, using an adjustable threshold, it will trigger when the neighbors are too loud. We think he was wise to include some time filtering that makes sure the loud noises are sustained and not just the result of someone bumping into the wall. When the system does detect loud music for a sustained period it triggers [Matthew’s] own CD player to pump out Who Let the Dogs Out? by the Baha Boys. It will play for a period of time, then shut off to listen and see if the neighbors are still rowdy.

He documents an actual run in the latter half of the clip after the break. We sure hope he’s living in a building with just two units, otherwise this will drive the rest of the neighbors batty as well!

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Decoding RF Link Using A PC Soundcard

July 2, 2012 by Mike Szczys 26 Comments

[Ray] wanted to use a microcontroller to send signals to some wireless power outlets. Instead of tapping into the buttons on the remote control he is using an RF board to mimic the signals. There are two hurdles to overcome with this method. The first is to make sure your RF module operates on the proper frequency. The second is to get your hands on the codes that are being sent from the remote control unit.

Now you could just hook your oscilloscope up to the transmitter and take a look at the timing of the signals. But most hobbyists don’t have that kind of high-end test equipment in their basement or garage shops. [Ray’s] approach uses something we all have available to us: a sound card and some open source software. He connected the data pin from his RF receiver to an audio plug and inserted it in the line-in jack of his computer. Using Audacity he recorded the signal as he pressed buttons on the transmitter. This method not only captures the data, but the time stamps native to the audio editing program let him easily work out the timing for each signal.

It’s kind of amazing what you can do with this audio analyation technique. Earlier this year we saw it used to measure response time for DSLR cameras.

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Chiptune Player Uses Preprocessed .MOD Files

June 27, 2012 by Mike Szczys 6 Comments

[Kayvon] just finished building this chiptune player based on a PIC microcontroller. The hardware really couldn’t be any simpler. He chose to use a PIC18F2685 just because it’s big enough to store the music files directly and it let him get away with not using an external EEPROM for that purpose. The output pins feed a Digital to Analog Convert (DAC) chip, which in turn outputs analog audio to an LM386 OpAmp. The white trimpot sandwiched between the chips controls the volume.

The real work on this project went into coding a program which translates .MOD files into something the PIC will be able to play. Because of the memory limits of the chip it is unable to directly use all of the instrument samples from these files. [Kayvon] wrote a program with a nice GUI that lets him load in his music and page through each instrument to fine-tune how they are being re-encoded. The audio track from the video after the break doesn’t do the project justice, but you will get a nice look at the hardware and software.

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Building A Boombox Where Tools Are Meant To Go

June 25, 2012 by Mike Szczys 28 Comments

[Danman1453] is ready to face the rest of his summer thanks to this toolbox boombox he built for outside use. It’s always nice to have some tunes when laboring at those not-so-fun jobs (we’ve got some windows that need re-glazing and you can bet we’re not doing that in silence). But if you can’t really hear it what’s the point? The highest volume [Danman1453] could get out of the consumer options he tried just wasn’t cutting it, and that led him to this project.

The only thing he bought to complete the boombox was some black spray paint. He already had an old toolbox for the enclosure, a head unit and the larger speakers from an old car, and the small speakers came from a set of computer speakers. Those are cleverly mounted in the compartments on the lid of the toolbox, pointed down so that they’re oriented correctly when the lid is propped open. The faceplate was even recycled by using wood an old shipping pallet.

He would like a little bit of advice though. When he’s playing a CD and the bass really gets bumping the head unit tends to skip. Does anyone have an easy method of isolating it from the speakers while still keeping it safe and sound in the portable enclosure?

Outdoor Stereo Helps Your Neighbors Learn To Issue Noise Complaints

June 6, 2012 by Mike Szczys 23 Comments

Backyard parties are going to rock over at [Effin_dead_again’s] house. That’s because he just finished building this outdoor stereo. It carries its own power supply so you can take it on the road with you, and we don’t think you’ll have trouble hearing it with the 240 Watt amplifier hidden inside.

He shared the equipment details in his Reddit conversation. A 12V lawn mower battery sits in the base of the wooden enclosure. One of the commenters mentioned the dangers of hydrogen off-gassing from that power source, but [Effin_dead_again] thought of that and included venting around the lid. The subwoofer is an 8″ Alpine, and speakers are out of a Hyundai car. The head unit has Bluetooth built in for easy connection to your smart phone. It of course has the ability to play CDs and MP3s too, and we’d bet you can tune the radio if there’s an antenna connected.

Need similar power but a bit more portability? Check out this stereo built into a cooler.

Tunes In The Icebox

June 4, 2012 by Mike Szczys 29 Comments

A couple of years back [Bryan’s] iPod went on the fritz. It wasn’t completely broken, as long as he kept it really cold it still worked. So what was he to do with the crippled device? We’ve all heard of elevator music. [Bryan] decided to invent refrigerator music.

First he needed some speakers. A trip to the Goodwill store netted him a pair for under $5. They need A/C power, and the project depends on sensing when the door to the refrigerator is open. He killed two birds with one stone by adding a light socket outlet adapter. This provides a place to plug in the speakers’ power adapter, and it only gets juice when the door is opened. The gimpy iPod just constantly loops through the tracks stored within, but you’ll only hear it when the door is open and the speakers receive power. Of course the iPod will eventually run its own battery down so [Bryan] ran an extension cord out the side of the door to a wall outlet. This interrupts the door seal and we wish there were another way to keep it contained within.

A Sample Player You Can Slip In Your Pocket

May 29, 2012 by Mike Szczys 8 Comments

This portable sample player packs quite a punch. [Lee] wanted a nice portable way to take his samples with him, but refused to water-down the features just because it is portable. He set of goal of playing between 3-8 simultaneous notes from a large assortment of stored samples.

Sample space was the first design consideration, and it’s hard to beat the price per megabyte of an SD card. After some calculations he concluded that it is possible to pull these samples off the card quickly enough to achieve his simultaneous note goal at CD quality frequencies, but only if there is little or no latency when reading from the card. This means [Lee] needed a fast processor so he chose the LPC1769 which is an ARM Cortex-M3 processor which can run at 120 MHz.

The project box includes room for a volume knob to control the output from the in-build headphone amplifier. There’s also a rotary encoder for selecting sample sets. But we’re a bit confused on this part as the device is MIDI controlled. [Lee] is the creator of the electronic Moolodeon, which itself has MIDI out and will be used as a controller for this project.