I’m hoping to use this category in my site to keep a project diary, so you can look forward to reading my random thoughts and musings.

Seriously though this project is, for me, the most daunting of the two to be completed this semester. I have little to no experience of systems and control so even coming up with initial ideas has been a huge struggle. My main stumbling bock has been the PIC chip circuit we created in the last week (details here), what is it? what can it do? how do I use it?!?

This will have to be my first area of investigation…

• Components available – what cool things can I use to make my product more useful/interesting?
• Materials – what could I use to build it?
• Products already out there – what are they made of? How much are they? How do they work?
• Aesthetics – how do I want my chosen design to look?
• Sustainability – how environmentally friendly can I make it? Can it be recycled?

Lots of questions but no answers yet, time for some research.

As our circuits were to be based around an PIC chip I thought it would be a good idea to find out what it is and what it does.

Well PIC just stands for Programmable Integrated Circuit, which is great but I don’t know what an integrated circuit is yet!

On surfing around I found this amazing article on what they are, how they were developed and what it meant for the electronics industry as a whole: http://nobelprize.org/educational/physics/integrated_circuit/history/

So now I know that inside my little black box with eight legs (urg, sounds like an electronic spider!) are tiny little components for memory, processing and input/output circuitry, no wonder they’re sometimes called ‘computers-on-a-chip’! They are programmed and built into a product to make that product more intelligent and easier to use. For example a garden light designed to turn on when it gets dark. An input into the chip would be a light dependant resistor, once it gets dark enough the PIC would tell the output, in this case the light to turn on.

So it works a little like this: Right, now I know what it is I need to get on and finish my circuit to see if I can make it work.

Right, now I know what it is I need to get on and finish my circuit to see if I can make it work.

This originally sounded like Dean was asking me to something on par with “just run along to the nearest dragons lair and bring me back some rubies would you , oh and careful you don’t get scorched along the way”. Me? Make a PCB? From scratch? Right.

First step, what is a PCB? Well as I found out it stands for Printed Circuit Board and is the basis for almost every  electronic product out there.It serves two purposes, as a stable surface to fix components to and as a means of making an electrical connection between them. As someone who has been on the fringes of several PC builds I know what a PCB looks like but have no idea how you would actually go about creating one.

Turns out, not the crazy, complicated quest I first thought. The process is surprisingly simple as long as your artwork isn’t printed backwards! (more on that later). I’ve detailed the steps below, hope you find them as useful as I do:

Step 1 – Get your artwork, we picked up ours from www.picaxe.co.uk. As some of us are relatively new to this we are making the basic PICAXE-08 circuit, designed for the smallest PIC chip they produce, details here axe001_pcb.

Step 2 – Print (the right way round!) onto acetate using a laser printer. Our first attempt was printed from the component view rather than the track view, this meant that the numbers printed on the board appeared the right way round even though the tracks were wrong! Unfortunately we did not realise this until we had finished the process and were soldering components to them, note to self, always double check artwork!

Step 3 – Warm up the UV light box. Peel off the black backing on the board to expose the photo-reactive chemical film over the copper, place the acetate sheet making sure it’s the right way up (When you hold the printed sheet over the board you need to be able to read any numbers or text) onto the light box and cover with the board, film side down, and expose for 3 minutes. (The guy in the photos is my colleague Steve who very kindly ran the demo for us, thanks Steve!)

Step 4 – You now need to develop the image  that has been transferred to the board. You need at make up a solution of (hmmm, can’t find my notes, will need to update tomorrow) in a shallow tray and place the board so it is entirely covered. Gently swish the solution over the board and you will see threads of blue running off the board, carry on until you can’t see anymore blue running off the board.

Step 5 – Now to insert the prepared board into the Rots-Spray etching machine to strip all of the unwanted copper away (H&S info on this machine found here). This machine also need warming up so make sure to turn it on at the start of this process. Fix the board into the holder shown below and slot into the chamber to the right (this unit has the capabilities to develop the board as well in the chamber to the left but it was  not operational when we were using it) there is a notch in the bottom that the holder sits in. Make sure you close the lid! The chemical used to strip the copper is ferric chloride (COSHH info here), it will stain just about anything and can eat through cloth. Set the machine to etch for 1.5 minutes and you will see it start to spray a brownish, yellow fluid at the board (be warned it smells!).

Step 6 – Once the machine has finished, wash the board in the middle slot in the tank to get rid of any remaining ferric chloride and cut to shape using the board guillotine. Using a little PCB drill make all the holes needed in the board. Tip: the drill will naturally find the middle of the hole if you gently hold the board and lower the drill slowly, it feels a little strange at first, normally when drilling you don’t want your material to move but it does work!

Right there you go. the lair was stormed, the dragon tamed (not slain, I think that’s mean) and the rubies gained and no longer shall I think of this as something beyond my capabilities. Now I just need to know how to use it…

• To produce a product that can be part of a batch production
• The product must include some mechanical or electronic or a combination of systems
• As the product is to be mass produced I need to work to a specific target market
• To explore areas of concern in my subject audit
• To produce an e-portfolio documenting my design process
• To utilise CAD/CAM to produce a quality product
• To develop strategies to work effectively and efficiently with new materials and processes
• To work with due regard for the workshop safety of myself and others

They fall under two (somewhat disparate!) titles, Lights and Money Boxes. The first thing that came to mind when thinking about this project was to make something that lights up, seemed to me the most obvious thing to do when you’re not sure about the range and scope of electronics. After doing a little research on components I came up with the ideas below:

LIGHTS (research images here and here)

• Childs customisable night light – different cases (colours, designs), plug in/battery operated, cases could be milled out of acrylic and would clip on to the base unit, can be turned on/off or put on to the light detection mode (light sensor to tell bulb to switch on)
• Childs customisable bedside lamp – different cylindrical cut outs/colours (slot on to the base unit), plug in/battery operated, cylinders could be laser cut and shaped around a form, motor inside to rotate the piece work cylinder. Can be on/off/light detection/rotating.
• Solar powered, customisable garden light – unit would sit on a spike to be positioned in the ground or on a clamp to fit on branches or garden furniture, cases could be milled from acrylic and clip onto the base unit, would be designed to switch on in low light.
• Adults bedside light – would be made out of semi-transparent/frosted plastic (thin veneered wood?), interesting shape, on or off would look sculptural, would have a dimmer function on turning it off to help you get to sleep, would leave a light facing the ceiling that would dim gradually over the course of 5 – 10 minutes to prevent the sudden switch from light to dark 

 After becoming a little more comfortable with the idea of making an electronic product things started getting a little more interesting. I loved toys with movement and sound when I was little, there was something a little bit magical about an object that could move or talk with little input (although I still think Furbys are a bit strange, even for me) a real sense of childish glee overtook me when I realised that I now have the opportunity to make something like that myself! My product though, was to be something useful; I didn’t want it to become the fad toy that would be abandoned once the next big thing was out. One object I always cherished as a child was my money box (hmmm… never really thought about it but I was quite a materialistic child…). It would have to be interesting though, like the Halloween themed coffin box, putting the coin in the designated area caused the skeleton in the coffin to reach out and drag the coin in to the grave (mwah ha ha ha! oh, sorry got distracted). I wanted to make mine just as interesting:

MONEY BOXES (research images here and here)

• Safe Money Box – To look very high tech with a keypad locking mechanism, poss. movement and sound effects when unlocked (clunk, hiss of releasing pressure seal for inputting the correct code, siren for hazardous waste and rotating hazard lights for incorrect code).
• Dragon Money box – Dragon would open mouth and stick out tongue to accept coin, pressure switch on the tongue would tell the mechanism to reverse pulling it back in and shutting the mouth, the head would then tilt back to deposit the coin into the dragons stomach, could also include light and sound, more scope for movement.

So here are my starting points, next step research and development…