2-bit Full Adder Using Just Thirty Six 555 Timers

February 28, 2011 by Mike Szczys 12 Comments

This 2-bit adder was a lot of work to build. It uses a total of thirty-six 555 timers and it does have the option of adding or subtracting numbers. It’s a rather unorthodox use of the part, depending more on the chip as an inverter and taking advantage of the fact that there’s an NPN transistor built into it. [cpu86] did use some PNP transistors to give him the ability to turn off some of the 555’s to get everything working correctly.

He explains the use of two’s complement in the subtracting feature but the process is just touched on very quickly. Luckily there’s a huge eagle schematic available with his project writeup so that you can follow along and really grasp how this thing works. We’ve generated a PNG and embedded it after the break for your convenience. You’ll find it just after the two videos of the device in action.

Continue reading “2-bit Full Adder Using Just Thirty Six 555 Timers” →

Analog Robotic Concepts

February 26, 2011 by Mike Szczys 20 Comments

Everyone’s getting on board with the 555 timer projects. But [Tom] didn’t just come up with one project, he shared a slew of ideas related to analog robotics. They’re center around servo motor control. You can see in the video after the break he has a pleasing way of sharing a lot of details while also making an easy to view demonstration video. He’ll put up a schematic for about one second and then move on, saving those that don’t care about the details by not droning on.

The first schematic that flashes by is the main circuit for controlling the servo motor. The rest of the concepts build from this circuit, using light, sound, flex, and other sensors as inputs. For instance, the setup above is using a light sensor. When the ball blocks the light the servo moves that vertical rod hitting it out of the way. When it swings back the process repeats. It’s striking how lifelike the reactions are, reminding us of insect movements. But this is really just the tip of the iceberg as he’s got a lot of future video ideas that we can’t wait to see.

Continue reading “Analog Robotic Concepts” →

DIY Lightning Special Effects

February 26, 2011 by Chris Nelson 3 Comments

Halloween may have come and gone but thats no reason not to take a look at this neat little special effects setup. Basically it uses an analogue circuit to monitor an audio signal and triggers some camera flashes using 5V relays. The idea is that you can play lightning strikes and other spooky sounds, and the system will trigger camera flashes to coincide with the lightning strikes. Adding in some color organs in addition to the camera flashes will dim your lights to help achieve a thunder like effect. Unfortunately there aren’t any schematics for the color organs (which technically might be just light organs) but that doesn’t detract from the seemingly well designed analogue signal processing. Check it out in action after the break.

Continue reading “DIY Lightning Special Effects” →

Hear That? It’s A 555 Timer AM Radio

February 25, 2011 by Mike Nathan 16 Comments

[Eric] recently built an AM radio based on a 555 timer, and posted a few pictures to the Hack-a-Day Flickr pool. He used the 555 timer as an AM demodulator and power amplifier in order to drive the speaker. A hand-wound inductor is used to tune the signal which is then superimposed over the ramp signal produced by the circuit he built. [Eric] points out that he chose a CMOS 555 timer because of its superior performance in this particular application since the timer is used in a bit of a nontraditional manner. He shared his circuit diagram as well as a great video walking through each part of his design, finishing off with a demonstration of the radio, which can be seen below.

This is yet another great project that will be entered in the 555 Design Contest – simple and elegant. We love seeing these, so keep them coming!

If you want to see more cool projects made by Hack-a-Day readers, be sure to check out our Flickr pool as well as the forums.

Continue reading “Hear That? It’s A 555 Timer AM Radio” →

Machine Pushes Cellphone Buttons From Anywhere In The World

February 24, 2011 by Mike Szczys 32 Comments

[Mok Young Bacq] works on the weekends for mobile game monitoring service. He has three cellphones that he uses for work, and although you would think this means he could work from anywhere in the world, the roaming charges are a killer. His solution was to build an incredibly intricate machine that can use three different cellphones (PDF) on his behalf.

Above you can see it perched underneath the apex of the ladder, but you’re definitely going to want to watch the video after the break. This interface method uses a camera to look at each phone. It’s hung pointing downward and moves like a pendulum to look at one of the three screens at a time. Each phone has one servo motor for each button, which uses a flexible cable as an actuator. Now he can take trips abroad, just checking in over the Internet for his two 17-hour weekend shifts (10am to 3am the next morning) working the phones.

This reminds us of the cellphone endurance tests. What happens when a button stops working?

Continue reading “Machine Pushes Cellphone Buttons From Anywhere In The World” →

Emulating Oric-1 Floppy Disk Hardware

February 19, 2011 by Mike Szczys 5 Comments

This device is called the Cumulus and it’s used to emulate the floppy disk hardware for Oric-1 and Oric Atmos computers. These 1980’s era computers included an expansion slot to which you could connect a floppy drive. That module, called a Microdisc system, also included the driver circuit which means you can’t just use a modern-day floppy drive as a replacement. [Retromaster] sidestepped the need for magnetic media all together by building an SD card interface which emulates the original module. We can tell by the use of a color screen and clean board layout that a lot of love went into the project. A CPLD implements the communications protocol used by the Microdisc system and creates all of the registers that would have been found on the original hardware. A PIC takes care of the SD card communications and the user interface.

With the exception of comforting noises, we’d bet there are few who have fond memories of using floppy disks. No wonder we’ve been seeing hacks to replace them quite a bit lately.

Measure Earth’s Rotation With PlayStation Move

February 19, 2011 by Mike Szczys 19 Comments

This somewhat odd-looking apparatus is being used to measure earth’s rotation. At the heart of the system is a PlayStation Move controller, used because of its dual-axis gyroscope which has the highest dynamic range compared to other available products like the Wii Motion Plus. It rests on a column perched atop a record player that was chosen because of its precision rotation rate. The two rings that flank the controller make up a Helmholtz coil which is used to cancel out the earth’s magnetic field which was found to be interfering with measurements taken by the Move controller. By recording data over time the experimenter can prove that the earth is indeed rotating, as well as ascertain longitude data and find true north. Check out the data-packed video after the break.

Continue reading “Measure Earth’s Rotation With PlayStation Move” →