Software Pulse Width Modulation

September 17, 2009 by Mike Szczys 11 Comments

daqq_pwm_schematic

Pulse Width Modulation is a topic that tends to give a lot of beginners trouble. [Daqq], whose nixie plasma ball we covered a few days ago, has a simple but effective PWM project that you should take a look at. The circuit used 9 LEDs clustered together into 3 sets of RGB modules and connected them to an AVR ATtiny2313 through some current limiting resistors. Most of the time the PWM function of the AVR’s timers would be used to generate the signal but this application calls for 9 signals which is more than can be produced by this chip. The workaround is to generate the signals using software PWM. Continue reading “Software Pulse Width Modulation” →

8-bit Binary Calculator

September 16, 2009 by Mike Szczys 41 Comments

binary_calculator

Don’t feel like shelling out $5 for a fancy factory made calculator that won’t even do binary math? [Jeff] decided to prove his mastery of gates and his disdain for base 10 by building a binary calculator using XOR, AND, and OR chips. Calculations can be input in two ways: through digital logic headers or by three banks of DIP switches used to enter the operator and the two operands. Although limited to addition and subtraction, this is a great way to make sure you really understand digital logic. Take a look at the rough design schematics in his album. The design is modular so if you have one of each gate and a few LEDs sitting around you can give this a whirl.

BBox MIDI Drum Sequencer

September 14, 2009 by Zach Banks 10 Comments

bbox

We’ve covered sequencers before, but reader [Johan] sent in his latest project that is much more minimalistic approach. Dubbed the BBox, he based his drum generator on an Arduino and an LCD display. Rather than synthesizing sound, the Arduino just outputs MIDI which is then interpreted by his Roland Juno-D. In building the device he used a favorite trick of ours to keep the interface clean. He then found an awesome banana box to use as a case. Although, the project may not be as functional as some of the others out there, it certainly has flair. Video of it in action after the break.

Continue reading “BBox MIDI Drum Sequencer” →

Dot Matrix Clock On The Way

September 12, 2009 by Jakob Griffith 25 Comments

[Kevin] sent in his almost finished open source dot matrix clock. Sporting a hefty 40 x 16 display powered by a PIC 18F he has complete pixel by pixel control of the graphics. Combined with with a triple buffer he is at least able to output 15fps, with planned 30fps. While this has great potential for a clock, what about going further? Twitter updates, chat messages, weather updates, the current airspeed velocity of an unladen swallow; it will be tough to beat the competition without some more features. Either way, its an awesome project and we can’t wait to see it completed.

Time Lapse Light Sculptures

September 8, 2009 by Mike Szczys 6 Comments

time_lapse_light_sculptures

[Jared] sent us a feature he posted involving time-lapse photography and an LED. Using a custom built aparatus an LED is moved on two axis’ during a long exposure of around thirty seconds. The frame is wood and PVC with two gearhead motors powered by AA batteries to provide the locomotion. The LED is powered by a 3v button cell and automatically transitions through different colors.

Hard Drive RGB Clock

September 7, 2009 by Jake W 28 Comments

[youtube=http://www.youtube.com/watch?v=XK9en2H7rBA]

We’ve brought you an HDD clock in the past, but [mb1988] tried to bring his project to another level by fully documenting it (in Polish). Inspired by [dzgdzzh]’s version of the same invention, [mb1988] decided to reverse engineer it (as well as make a few changes) and base it on the powerful ATmega128. Since this clock, along with most HDD clocks, can only display solid lines of radii, it cannot be used to display text. However, color schemes and animations can be toggled using a remote control. The housing itself is also pretty impressive. The back part of the enclosure was molded out of Rayobond, while the front was simply the original HDD case but spray-painted black and etched with some original artwork. The source code, schematics, and PCB layouts are freely available to download on the project’s thread, but you will have to login to the forum to access them.

700 Lumen LED Bike Lamp

September 3, 2009 by Mike Szczys 15 Comments

700_lumen_bike_lamp

We’ve seen bright bike lamps before. This one caught our eye because it needs a heat sink while in operation. [700lumenLED] built a super bright light for his bike that features an aluminum enclosure and heat sinks to protect the LEDs against overheating. Some nice work was done incorporating the 12v battery into a bike bottle with the power switch and a dimming potentiometer attached to the bottle cap.