Tag Archive | "EMSL"

Project – Arduino “Book Monster”

Introduction

Recently we saw a neat project by the people from Evil Mad Scientist – their “Peek-O-Book“, a neat take on a book with a shy monster inside, based on hardware from their Snap-O-Lantern kit. Not wanting to fork out for the postage to Australia we decided to make our own version, of which you can follow along.

This is a fun project that doesn’t require too much effort and has a lot of scope for customisation. There’s no right or wrong when making your own (or this one!) so just have fun with it.

Construction

First, you’ll need a book of some sort, something large enough to hide the electronics yet not too large to look “suspicious” – then cut the guts out to make enough space for the electronics. Then again it’s subjective, so get whatever works for you. Coincidentally we found some “dummy books” (not books for dummies) that were perfect for the job:

dummy book

After spraying the inside with matt black paint, the inside is better suited for the “eyes in the dark” effect required for the project:

dummy book internal

The “book” had a magnet and matching metal disk on the flap to aid with keep the cover shut, however this was removed as it will not allow for smooth opening with the servo.

The electronics are quite simple if you have some Arduino or other development board experience. Not sure about Arduino? You can use any microcontroller that can control a servo and some LEDs. We’re using a Freetronics LeoStick as it’s really small yet offers a full Arduino Leonardo-compatible experience, and a matching Protostick to run the wires and power from:

Freetronics Leostick and Protostick

By fitting all the external wiring to the Protostick you can still use the main LeoStick for other projects if required. The power is from 4 x AA cells, with the voltage reduced with a 1n4004 diode:

battery power and diode

And for the “eyes” of our monster – you can always add more if it isn’t too crowded in the book:

Arduino LEDs

We’ll need a resistor as well for the LEDs. As LEDs are current driven you can connect two in series with a suitable dropping resistor which allows you to control both if required with one digital output pin. You can use the calculator here to help determine the right value for the resistor.

Finally a servo is required to push the lid of the book up and down. We used an inexpensive micro servo that’s available from Tronixlabs:

Arduino servo

The chopsticks are cut down and used as an extension to the servo horn to give it more length:

Arduino servo mounted

Don’t forget to paint the arm black so it doesn’t stand out when in use. We had a lazy attack and mounted the servo on some LEGO bricks held in with super glue, but it works. Finally, here is the circuit schematic for our final example – we also added a power switch after the battery pack:

book monster schematic small

To recap  – this is a list of parts used:

After some delicate soldering the whole lot fits neatly in the box:

Arduino book monster final

Arduino Sketch

The behaviour of your “book monster” comes down to your imagination. Experiment with the servo angles and speed to simulate the lid opening as if the monster is creeping up, or quickly for a “pop-up” surprise. And again with the LED eyes you can blink them and alter the brightness with PWM. Here’s a quick sketch to give you an idea:

You can watch our example unit in this video.

Frankly the entire project is subjective, so just do what you want.

Conclusion

Well that was fun, and I am sure this will entertain many people. A relative is a librarian so this will adorn a shelf and hopefully give the children a laugh. Once again, thanks to the people from Evil Mad Science for the inspiration for this project – so go and buy something from their interesting range of kits and so on.

And if you enjoyed this article, or want to introduce someone else to the interesting world of Arduino – check out my book (now in a third printing!) “Arduino Workshop”.

visit tronixlabs.com

Have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column, or join our forum – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

Posted in arduino, evil mad science, freetronics, leostick, projects, tronixlabs, tronixstuff, tutorialComments (0)

Kit review – Evil Mad Science Diavolino

[Updated 17/01/2013]

In this review we examine a kit from the people at Evil Mad Scientist Laboratories – their Diavolino. In English this means “little devil”. This little devil is a low-cost Arduino Duemilanove compatible board – with a few twists.

This is sold as a bare-bones kit, so you really need to plan ahead with regards to how you want to use it. It does not include a USB interface, nor power socket, header sockets, IC socket, nor a voltage regulator. This may sound like a bad thing – but it is not 🙂 This kit is perfect for those who wish to make a permanent project using the Arduino system, without spending the extra on a whole board, and without the hassles of making your own barebones PCB version. So let’s have a look… the kit ships in a nice reusable anti-static bag:

bagsss

and upon turfing out the contents, one receives:

partsss

Which is just enough to have a basic setup. The instructions on their web site mention the inclusion of some zero-ohm resistors to be used as jumpers, but these were not included. However that is a non-issue, some resistor lead clippings will do the job. EML have gone to a lot of trouble with the printed-circuit board. It certainly is different to the normal green or blue ones out there. It is very well detailed with component position labels, and all components are through-hole. The other side of the board is also printed this way:

rearpcbsss

There is also a nice instruction laminated card included in the bag which has enough information to get your started. Furthermore, there is an excellent instruction manual available for download here (10 MB). Finally, this is an open-source hardware product, so the designers have also made available the gEDA CAD files.

Now for assembly. Normally I would photograph each step, however the instructions available for download are so good, I won’t need to 🙂 Eleven out of ten for the instructions. Soldering it together is quite easy, however I did supply my own IC socket – I am just not a fan of soldering expensive parts (I get the shakes sometimes), however if you are confident, go for it.

Before deciding to permanently solder in that microcontroller, you will first need to take into account how you will be programming it. As the board does not support the usual native USB interfacing, you can’t just plug in the cable like a normal board. The Diavolino does have an interface for a TTL-level cable – so if you have (for example) a USB FTDI cable, you can program it via the USB port. But considering an FTDI cable is around $20, you might as well just buy a normal board like an Eleven instead. It only took around fifteen minutes to get to this stage:

almostsss

For my personal use as another bench-based board  (that sounds a little odd…) I will power it from the FTDI cable, so a link is required behind the TTL input pins – as well as adding the  6-pin and 8-pin header sockets. The easiest way to solder those in is to turn the whole thing upside down and plug it on top of an existing shield, as such:

socketsss

However if you don’t want to buy an FTDI cable – and you already have another Duemilanove board, the cheapest way to program the microcontroller is to just insert it into a  Duemilanove-type board, upload the sketch, then drop the chip into the Diavolino.

You also need to decide on how to power the board. If you supply 4.5~5.5V, all you need is to feed in the power wires. If you are going to use more than 7V, you will need a 78L05 power regulator, 10uF electrolytic capacitor and a DC socket to use a plug-pack if necessary (see the instructions). However, a 78L05 can only supply 100 mA of current (see the data sheet.pdf), so you won’t be able to use some products like a MAX7219 LED driver and many LEDs.

Unfortunately there isn’t enough space for a TO-220 sized 7805 1 amp regulator, so you will need to introduce 5V using an external supply hard-wired into the board if you need more than 100mA of current. Or you can power it from the USB FTDI cable for desktop use.

finishedss

 

So there you have it – another successful kit build. This was an interesting alternative to the Duemilanove, and a great solution for a permanent project, or for someone who wants another board on the cheap. If you can work with the power supply current restrictions, all is well. So get one or more, have fun with it, and give one  to someone else to get them cooking as well.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.
[Note – this kit was purchased by myself personally and reviewed without notifying the manufacturer or retailer]

Posted in arduino, diavolino, evil mad science, kit reviewComments (0)


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