Sometimes, the best birthday presents are the ones you give yourself. In [Dino]’s case, they’re the ones you make for yourself. In honor of his 55th, he built the Sqonkbox 55, a 13-note cigar box organ based on a 555 and amplified with an LM386.
It’s based on a 555 wired in astable mode, turning it into an oscillator that outputs a frequency. This frequency is determined by the resistors between pins 6 and 7, another between 7 and 8, and the capacitor between pin 2 and ground. [Dino] shows a breadboard version first, with a single tuning pot and momentary acting as a piano key. As he explains, this portion of the circuit is repeated 13 times with pots and momentaries that he arranges like piano keys through the lid of a cigar box.
“Sqonkbox,” you ask? A second 555 in astable mode sends the output through an LED. This LED stands face to face with an LDR, and they are shrouded in this configuration with black heat shrink tubing. The ‘sqonk’ 555 changes the frequency of the first 555, providing a clippy, rhythmic tone at the rate set by a potentiometer. [Dino]’s full video of the build is after the break. A BOM is forthcoming, but it’s easy enough to puzzle it out between the video and the lovely, Forrest Mims-esque schematic. Continue reading “Sqonkbox 55 is a Cigar Box Organ of Awesome”
The Magnetophone is the latest electro-acoustic instrument from [Aaron Sherwood]. This tower contains 14 strings, and 14 hand-wound electromagnets. By energizing each electromagnet with a square wave, the strings can be vibrated to create music.
The brains of the device consist of an Arduino Mega attached to the top of the tower. The microcontroller has 6 timers, which allows for 6 notes to play at the same time. An open source tone library was used to generate square waves at the correct frequencies. These square waves are amplified by LM386 based circuits, which provide enough power to the coil to oscillate the string. By using square waves at specific frequencies, overtones of strings can be created.
This isn’t the first time we’ve seen [Aaron] combine strings and electronics. His Glockentar used solenoids to strike strings. However, this project provides new possibilities by allowing the rate of oscillation to be controlled precisely. You can see the instrument in action after the break.
Continue reading “The Magnetophone”
Headphone amplifiers make for simple, practical electronics projects. The Bass Bump Headphone Amp is no exception, since it’s made out of easy to source parts, and can be built on a proto-board.
We’ve seen many variants of the classic cMoy amplifier, including this pretty one. The Bass Bump differs by providing control over bass frequencies. It does this by putting a filter in front of the amplifier, with a potentiometer to select the mix of frequencies. This goes into a LM386 audio amplifier. At the output is a Zobel network to keep the impedance low at high frequencies. The amplifier can be powered from either a 9V rechargeable battery, or a USB port.
It’s a simple build, but definitely a good one to try on a rainy day. The write up explains how the analog circuitry works, and gives you full instructions on how to build it. After the break, check out a video overview of the project.
Continue reading “Bass Bump Headphone Amp”
[Dino] is about three-quarters of the way through his talking box project. He’s completed one of the two boxes, and is showing off the technique he uses to marry motion with sound in order to mimic flapping lips with the box top.
You may remember [Dino’s] first look at the EMIC2. It’s a single-board text to speech module which is what provides the voice for the box. But what fun is that without some animatronics to go along with it? So [Dino] started playing around with different concepts to move the box top along with the speech. This is easier said than done, but as you can see in the video after the break, he did pull it off rather well. He built a motor control circuit that takes the audio output of an LM386 amplifier chip and translates it into drive signals for the motor. The shaft is not directly connected to the lid of the box. Instead it has a curved wire which is limited by a piece of string so that it doesn’t spin too far. It lifts the lid which is hinged with a piece of cloth.
Continue reading “[Dino’s] talking box(es)”
[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.
Continue reading “Chiptune player uses preprocessed .MOD files”
[Michael Chen] felt the sound his PSP was putting out needed more dimension. Some would have grabbed themselves a nice set of headphones, but he grabbed his soldering iron instead and found some space where he could add a bigger speaker.
Mobile devices tend to cram as much into the small form factor as possible so we’re surprised he managed make room. But apparently if you cut away a bit from the inside of the case there is space beneath the memory card. [Michael] cautions that you need to choose a speaker rated for 8 ohms or greater in order to use it as a drop-in replacement for one of the two original speakers. But he also touches on a method to use both stock speakers as well as the new one. He suggests grabbing an LM386 op-amp and a capacitor and hooking them up. Yep, there’s room for that too if you mount it dead-bug-style. We wonder how the battery life will be affected by this hack?
[Nicholas] wanted to add some flair to his RC car. In addition to the headlights that you see above, there’s brake lights, and a horn that plays “Dixie” like the General Lee in the Dukes of Hazard. All of this is triggered by the wireless controller, but he figured out a way to monitor the servo signals in order to add the additional features.
The hack is driven by a Propeller chip. [Nicholas] patches into the servo lines by adding a servo-in and servo-out header to his prototyping shield. With that in place he’s able to tap into the voltage and ground pins to power the microcontroller. By attaching a 4k7 resistor to the control line, he can listen in on the servo signals using the Propeller.
This RC car has a throttle servo. So when the throttle is opened all the way up the Propeller chip flashes some white LEDs in the headlights, and uses an LM386 audio amplifier to play a tune. When the throttle is pulled all the way back the brake lights are activated. Don’t miss the test footage of this which is embedded after the break.
Continue reading “Adding sound and light to your radio controlled vehicles”