In this review we examine the Game of Life kit from adafruit industries. This kit is simple to construct, yet interesting to watch in operation, almost mesmerising. If you love blinking LEDs, this is the kit for you. Furthermore, it is very easy to construct which makes it a great kit for someone who is learning to solder. But before we run through putting it together, what is the Game of Life?
In 1970, a mathematician by the name of John Conway created the concept of the Game of Life, which is a example of a cellular automaton. Imagine a grid of cells, and each cell can either be dead or alive. Each cell interacts with the cells around it, and these neighbouring cells determine the life of the cell that they are neighbours to. There are a few simple rules to this:
- a live cell with less than two neighbours will die, due to under-population;
- a live cell with more than three neighbours will die, due to overcrowding;
- a live cell with two or three neighbours lives on;
- a dead cell with three neighbours will come to life, due to regeneration.
For example, consider the following situations:
1 – death; 2 – life; 3 – death; 4 – life; 5 – rebirth; 6 – death. This kit displays a simulation of the Game of Life process using a 4 x 4 grid of LEDs. Once you start watching the kit in operation, you often try to predict what will happen next. So, let’s assemble it and see what happens.
As usual, adafruit ship their kits in reusable anti-static bags:
Upon opening it up and turfing out the contents, we are presented with the following:
Everything is included to make the kit operational – no surprises. I scored an extra green LED – thanks! The kit can operate from between 3 and 5 volts, hence the 2 x AA cell holder included. The PCB is of excellent quality, with strong solder masking and a very descriptive silk screen:
This really is a simple kit to assemble. All the resistors are identical, so you can insert them into the board and solder them all in once hit. Time to fire up the iron and the fume extractor…
Careful when clipping off the excess leads, they can fly all over the place!
Next for the IC socket. Good to see a socket was provided:
At this point I would like to mention that all the documentation for the kit, instructions, schematic, code for the microcontroller – everything – is available freely, as this is an open source kit. If you intent to make your own, or modify the original design, you must respect the terms of the original Creative Commons licence as detailed in the documentation. Moving on, time for the capacitor and the link. The original design used an LM7805 regulator to control the incoming power supply, however this version (1.3) can operate from 3 to 5V, so an LDO isn’t needed. Therefore a link is placed between pins 1 and 3 of the regulator’s spot on the PCB:
Also note that there are three spaces for capacitors, but only one is necessary – solder it into the space for C3. I put it into C2 by accident, but luckily this is acceptable for the design, and I had some spares in the stock here. Now it is time for the LEDs. The kit ships with green LEDs, which look fine. My original plan was to solder in snap-off pin sockets so I could change the LEDs over at a whim, but none in stock. So on with the green! For visual appeal they look good flush with the PCB, as such:
and in with the rest:
Almost finished, time to solder in the power/reset button and we’re done:
Hooray – the main work is done. The six holes on the left of the IC are for in circuit programming, but I’m an arduidan at the moment, so will leave that alone. The IC is already programmed before it leaves for the outside world, so you don’t have to worry about it. Next was to test the board and make sure it worked. I loosely connected 5V and hit the power button:
Looking good. Now for the power supply. Although it can run from 2 x AA cells, mine will just sit on the desk. Last month I bought a few USB extension cables for $1 each, so I can just chop one up and use it to power the GOL from my PC. The first thing to do in this case is separate the wires in the cable, and determine which is which:
Luckily for me this cable had the power lines appropriately colour coded. However, one should always check, so I plugged it into the PC and set the meter on the black and red wires:
5.04 volts DC – close enough for me. I soldered in the lead, and also screwed in some spacers to act as support legs so the kit will stand up on its own. And as a long-term temporary measure, a great wad of blutac to hold the wire and keep the pressure off the joints:
Hey, it works for me. Anyhow, the assembly is finished. Time to clean the desk off, put the soldering iron somewhere safe to cool off, and wash my hands. The whole lot took just under one hour, including checking the news website every now and then. It has a place just next to my PC:
To operate the GOL is very simple, once power is applied, hold down the button to turn it on and off. Then you can reset the cells with a quick press if you are bored with the pattern. Here is a video of it in action:
So there you have it – another successful kit build. This was a lot of fun, I enjoyed learning about John Conway and his theories, and enjoy watching the display. If you are feeling adventurous you can actually connect these kits together to form larger, blinkier games of life. Details of this and other things is available in the kit’s documentation pages. So get one, have fun with it, or give it to someone else to get them interested in electronics.
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[Note – this kit was purchased by myself personally and reviewed without notifying the manufacturer or retailer]