I love the smell of burning semiconductors in the morning

My 3D printer is down for an extended break. While fixing the connector problem, I accidentally plugged the X sensor in one location over to the right, shorting 5V to ground on my Arduino Mega that controls the printer.
How did this happen?
I was fixing the connector issue mentioned in a previous post and was testing it. I was just inserting the last connectors for the X, Y and Z end stop connectors.
I was in a hurry to do something upstairs, I just pushed them into their location, I never turned it on.

Next day I turned on the printer and noticed the LCD did not come on. I quickly turned it off and went over to the control board and could instantly smell the distinctive smell of burning semiconductor.

I remembered the last thing I did and, in better light, I could see that I had shifted the connector over one location. I had caused a short circuit. To fix it I removed the regulator from another Arduino board that I had. (I will order a new regulator when I get a chance). Soldered in the part.
It now appears to be working again.

I got a Raspberry Pi, now what?

Last Christmas I got a Raspberry Pi as a present. I ran out and got a used hdmi monitor for $40 so I could try it out.
I decided to choose Raspbian for my operating system but I had to find instructions for installing it from Linux onto a SD card. It seemed so complicated. Even though I have used Linux for several years now, I really do not use the command line very much. The easy instructions were there if you use Windows.

I nervously loaded Raspbian on to a SD card. knowing that it could wreck my system if I made a mistake. The first few efforts did not work because the instructions were written by someone who knows the CLI very well, and was not described with enough information for someone who had not done this a billion times before.

It booted OK and I began to play around with it. My first thought was I could use it in my Dalek: speech, camera, motor control and remote control all on one PCB. But after doing a little studying about the GPIOs and the overall capability, I realized the amount of current that the R-Pi draws, the limitations of the GPIO and of the overall speed and other complications. I felt that I could accomplish 80% of the items with a Picaxe or Arduino but without some of those extra complications.

So if not for the Dalek, what should I do with it? Well I thought I could turn it into a media centre, however we have a Boxee, a Roku and a Xbox already. How many media centres do I need?
I started looking at what other people had done with their Raspberry Pi’s but I could not find anything that grabbed me or that I liked that could not be done with an Arduino.
I was ready to install a media centre on to it, then inspiration came.

We had planned to have our kitchen renovated for the last year and I suggested to my wife how we needed a computer for the new kitchen. It was sort of a joke when I suggested it, but I looked on line and found a 10″ touch screen available. $134 plus s&h. I suggested this to my wife expecting her to squash the idea but she said, yes, go for it.

I promptly ordered the touch screen (before she could change her mind). It took 9 weeks for the screen to arrive because even though the website showed it was in stock it actually was out of stock. During this time I started to look for a suitable programming language and define the GUI in my head. I assumed that I would actually be using Raspbian.

A sound Arduino sandwich

At Maker Faire or two ago I bought the Voice Shield kit that is produced by SpikenzieLabs (http://www.spikenzielabs.com).
It fits on top of the Arduino and only uses a few pins of the Arduino so there are lots of other pins available to do other things like trigger a sound, or whatever.

It is based around the ISD4003. (I have used the ISD2560 in previous projects).

I was a little intimidated by the instructions on how to get the interface up and running, but I eventually figured out what I was missing and then it was pretty easy.

Basically you load the ISD4003 with sounds using the separate program, (available from their website) by sort of giving the words a number. Then after that, that program is gone and you can play them using by calling the numbers in your own program.
There are some code snippets there to sort of give guidance.

It actually sounds better than the ISD2560 and it comes with a small amplifier so testing does not require you to build an amplifier to hear things. I found trying to take the sound from my computer wasn’t so easy. There was some crackle noise coming through the computer which was also being recorded. I used my MP3 player and took the output from the headphone jack and the sound was very clean after that.

Board for speech recognition
Voice recognition board

I made a carrier board to take some inputs from the Voice Direct speech recognition module.

Here are the electronics that I plan to add to the 1812. There is a servo motor, a speaker, a Sharp gp2d12, Voice Direct module, Arduino and Voice Shield. Missing are the batteries and some LEDs.

Arduino and sound shield
Voice shield

Eye stalks

Here you can see the eye stalks have been added to the body and the whole thing is starting to take shape.

The microphone is hidden in the utility stalk that sticks out at the front. Not sure if I will add a claw or something there.

The electronics are all working, with the exception of the servo. The servo is still to be wired up to an output on my Arduino board.

Getting close to finishing. I just need to add a little detail to the paint and connect the LEDs, add the servo and some sort of linkage to move the eye stalks.

DRD with eyes stalks attched
Eye stalk added to body of DRD



Whistle while you work 1812 style

I bought this speech recognition kit a while ago (well, around 5 years ago). Initially I had all sorts of ideas on how to use it until I found it was a little limited. The board was made by Sensory Inc. and it was called the Voice Direct II. I say was, because it is no longer available.

I discovered after reading the sparse documentation many times over that it has 15 keywords that can be programmed in. However, for it to listen for a word in a sentence, you had to recreate the room ambiance almost exactly every time for it to recognise the speech efficiently. I also discovered that it was the very small brother to a much more expensive, better system that could recognise anything and be programmed to react in many ways.

This meant that most of my plans were pretty well shot. I had been thinking about 1812 the DRD and how it would be cool if you could whistle the first few bars of the 1812 Overture and have it reply back.

The Voice Direct module was basically a development kit board, and so after testing that the functionality I wanted was available, I decided to build my own PCB that could do what I needed. Here is the photo of it.

It is basically the development board with a transistor to switch 5v input to an Arduino.
The switches allow me to program it on the fly, however in the mode I am using, I need to press a button to tell it to listen for a word and then as soon as it recognizes the word, it immediately outputs a logic low for 2 seconds.

board for Voice recognition
Voice recognition board

I can now whistle the first few bars of the 1812 Overture and it will respond. If I continue whistling it will respond with the next few bars. This will be mounted in my 1812 very soon. The Arduino sort of takes care of everything else. More about that in my next post.

Arduino not Harduino

It was meant to be quick and easy, and after going to so many Maker Faires I had several Arduino PCB modules waiting to be used

The Book of Pure Evil (from the TV show Todd and the book of pure evil) was the goal of this project. A lot of the project is in the paint job applied to the book rather than the electronics.

Large craft book
A large “book” type box


The book is actually fake and is meant for display and storing knick knacks and looking nice on a shelf. When I saw the book in Michaels, it seemed spot on, and it was on sale too – perfect. I immediately knew that this would be a great quick project, which I needed as a lot of my time was being taken up with other things. This was also to be my first Arduino project. The plan was to play around with the Arduino and create a simple LED matrix.

book with star shape cut into it
Slice an eerie opening in the shape of a pentagram


A pentagram shape was cut out of the cover of the book and some perspex was inserted into the slots. The matrix has 34 LEDs, (not for any real good reason, I just wanted 6 LEDs on the points of the pentagram). I examined an LED blink sketch and an LED glowfade sketch and modified the code from there. I ended up with a book that glows in a sort of evil way.

Matrix the LEDs
Spaghetti wire as may LEDs as possible


The hinges are made from polymer clay and then painted to look like aged metal. The devil horns were made by dipping a hand into one of those stone kits to make imprints of child hands. And the finished book looks like this.

Book of pure evil
Add hinges, paint it up and add a creepy hand