555KitTestCircuit

A few days ago, I saw this kit from Evil Mad Scientist (by way of Adafruit). My first reaction was more or less “… That’s brilliant!” I love projects that have a healthy dose of wackiness as part of the recipe. Don’t get me wrong, I appreciate projects that are purpose-built to accomplish a goal. But this kit in particular jumped out at me for two reasons.

But before that, the ‘What.’ This kit takes the internal workings of a 555 IC and, with resistors and transistors, re-creates all the functionality of the humble little chip. Plastic “legs” complete the IC persona, and screw terminals allow for easy hook-up connections to protoboards or “dead bug” style circuits. The PCB is quite hefty, and the silk screening divides the different block components of the 555 circuit. It’s a great piece to look at, and it just happens to be completely functional. Bonus points.

First, the kit is most clever. Kit designer Eric Schlaepfer basically ripped the lid off of a 555 IC and blasted the thing with an Embiggening ray. Sure he could have just thrown the components onto a breadboard, but that’s no fun. The inclusion of the legs and the ‘notch’ on the silkscreen instantly inform anyone familiar with electronics what this is. Of course, the giant ‘555’ printed on it doesn’t hurt either. The giant terminals are a nice functional and aesthetic touch. So were I a judge on Iron Chef: Electronics Edition, I would award full points for creativity and originality.

Second, upon seeing the kit and instantly knowing that I wanted one, I knew that I would need to brush up on my 555 knowledge. I admit, I’ve played with 555s in the past, but I’ve never given much thought to the internal workings. So after having some fun putting the kit together and testing the included (astable configuration) test circuit, I took to the Tubes and sought out some diagrams and videos explaining the design and operation of the small but mighty 555 timer. I’ll include some of my findings below.

In a nutshell, the 555 timer works by using two voltage comparators and a flip-flip to generate pulses on the output pin. The two most common configuration modes are astable, in which the external circuitry causes the 555 to generate a constant pulse waveform, and monostable, where an external trigger causes the 555 to generate a single pulse. One of the key components to these common circuit configurations is the capacitor. When the capacitor reaches a certain fraction of the supply voltage, the flip-flop is “actuated”, the output pin goes high or low, and the capacitor will start discharging or re-charging. Obviously this is a very simplistic explanation, but the rate of capacitor charge and discharge (governed by capacitor and resistor values) are key to the timing applications of the 555 IC.

So to sum up, yay for creative kits that cause you to go out and (re)learn stuff! The cool thing about the 555 chip is that it is very much a building block to bigger things. There are plenty of resources out there for 555 applications and project ideas. I’d like to thank Eric Schlaepfer for his awesome kit idea and Evil Mad Scientist for helping make it available to the masses! I think it quite possible that you might see the 555 creep into future Maniacal Labs projects.

-Dan

Here are some resources I found while brushing up on the subject:

Of course, Wikipedia has a good synopsis of the 555, as well as some of the more in-depth maths detailing the particulars of how the different configurations function.
en.wikipedia.org/wiki/555_timer

The datasheet from Signetics, who developed the 555 in 1971:
www.datasheetarchive.com/dl/Scans-064/DSA2IH00140042.pdf

From the Sparkfun series “According to Pete”, Pete walks through some 555 basics.
youtube.com/watch?v=qwPtSkWyjWc

This video is long, but the link takes you to right where he demonstrates the inner workings of a monostable 555 circuit. The whole video is definitely worth a watch.
youtube.com/watch?feature=player_detailpage&v=SX01x1z7fTY#t=610

A few projects featuring one or more 555 timers:
555-timer-circuits.com

And some more pics from my build:

Friend of Maniacal Labs, Josh, is a huge Ghostbusters fan. How much, you ask? This much:

Ecto Mini

Why yes, that is a Mini Cooper Ecto-1.

A couple weeks ago, Josh emailed me asking if it was possible to get en Epoch Clock Kit with blue LEDs. Obviously, I was intrigued and asked him why. To which his answer was this video:

Yup, that’s a Proton Pack, the only problem with it being that it didn’t belong to Josh. He has one, but without the awesome, pulsing LED bar. His initial thought was that he could just install the blue LEDs in the clock in place of the red ones (while also changing out the 330 ohm resistors for 150 ohm). Unfortunately, after some measuring we realized that the 6.5″ long clock was a bit too long for the slot in his Proton Pack. But after a little brainstorming, we realized that if we reconfigured the LEDs to two columns of 32 an spaced them slightly farther apart it should fit perfectly. The original idea was to wire it all up on some perf-board but then he wouldn’t be able to get the desired spacing and, well, it would be somewhat of a pain to build. So I decided to see what I could come up with in terms of a custom printed board and this was the result:

ecto adapter front

So, now the plan was simply to solder female headers to the clock board, solder some more to the above adapter board, onto which all the LEDs go, connect the two with some ribbon cable, and reprogram the firmware a little to get the desired animation. The adapter was pretty cheap for three copies from the wonderful OSH Park so Josh ordered some and I got a kit to him with some blue LEDs that I picked up in a recent Mouser order. Then, today, Josh sent me this:

Wow I’d say that’s pretty spot on for the animation shown in the first video! Now I want a Proton Pack just so I have something to put one of these in!

Here’s some more close up pictures of the final build:

Once this goes in the actual pack, I’m sure it’s going to look awesome and will really add to the authenticity.

Want to make your own? As is our way, all the source code and board designs are completely open source and can be downloaded from the GitHub Repository. Just grab a kit from us, send off the adapter to OSH Park and load up the custom firmware!

It’s projects like this what really make us here at Maniacal Labs love what we do. When we designed the Epoch Clock we had a few ideas for alternate uses but it’s the projects that we didn’t think of that really astound us. We wouldn’t even be here without such a great community.

John over at tronixstuff.com has a review of our Epoch Clock kit. He offers a great walk-through of the un-boxing and building experiences, complete with pictures. He also offers a great explanation of Unix time. A big thanks to John for his consideration of our product! And, of course, we’re glad he liked it!

(tronixstuff.com is based in Melbourne, Australia and was started in 2010 by John Boxall. The site features electronics kit reviews, Arduino tutorials, and other assorted projects. Very cool stuff, so check it out!)

Do you live in the Raleigh/Durham area? Are you a fan of the Open Source movement? You’re in luck! Check out RTP 180: Open Source All The Things on September 17th (for free!). The event features guest speakers from three schools you might have heard (NC State, Duke, and UNC), as well as local members of the Open Source community. In addition to basing our operation on the tenants of Open Source, we here at Maniacal Labs enjoy supporting local people and organizations who champion the cause.

The event is free, they just ask that you RSVP (“buy” a free ticket). See the Eventbrite page for more details. We’ll be there, and we look forward to seeing you there as well!

Probably the hardest part of assembling our Binary Epoch Clock Kit is keeping the LEDs aligned and all pointing the same direction. So we designed this simple tool to help out with that process. Not only does it help keep all of the LEDs aligned, but it makes soldering them in much, much quicker.

Normally, per our instructions, you would solder the LEDs in four at a time. But with this, simply insert all of the LEDs and then fit the jig onto the front of the clock PCB. It will hold all of the LEDs in place and correctly aligned while the board is flipped over. No need to even bend the leads over, to hold them in place, before soldering!

If you have access to a 3D printer, you can grab the model file from Thingiverse and print your own.