Since my first exposure to computers and video games, I have wanted to design and build my own. Lacking, however, the resources and knowledge, I thought it would just be a pipedream. Well, fortunately for me, that is not the case. The technology is to the point where just about anyone can do so and for just a little money and the internet.
Microcontrollers are the key and companies like SparkFun and AdaFruit can supply the bits. If you are really tight on funds or just cheap (like me) you can save a bit by shopping eBay.
So, what can these microcontrollers do for you? Well, anything you want. And, yes, they can play games.
My original plan was to use something like AdaFruit’s Trinket for the brains and the Nokia 5110 LCD for the screen. Well, the Trinket is just too limited (and, frankly, difficult to program.) During a lengthy eBay search, I found a bunch of Arduino UNO clones that fit in about the same space as the Trinket, only with more I/O and more memory. I ordered a few of them and then waited almost a month to get them. In the mean time, I used my UNO to start writing code.
Along the way, I discovered the Arduino’s were capable of video, so I spent a few weeks playing with that and have built a game console that I will revisit once my plate is clear. Adafruit and other vendors sell interfaces for the Wii Classic Controller and the Nunchuk…both of which are very easy to code.
Back to the handheld. The Trinket filled in, physically, for my board layout. When the Mini Pro finally arrived, I socketed it and began to wire it up. A strip for the 5110, connector for the speaker and daughter board for the audio amplifier. I wrote up a short demo that married the audio to the graphics library and produced a static Mario splash screen and beginning of the game. It plays the Super Mario Brothers 2 theme upon startup.
My next tasks include a controller (a matrix of four buttons: Left, Right, Shoot, Start/Stop) and a case. The actual game code will be last. I want the hardware nailed down before I do all of the code.
The system will run off of three 1.5 volt AA batteries. I wanted to use a rechargeable battery, but the added complexity is more than I want to deal with for now.
The case is my biggest headache. I was going to use Lego’s, but the cost is more than I want to pay. I have an old Mattel JuiceBox that I will attempt to use. It looks big enough and already contains a battery compartment, holes for the controls and a speaker bay. It’s just really ugly.
I am also building version two of the handheld concurrently. This one will be for myself (the other is for my step son) so it doesn’t need to be as friendly and compact. At some future point, I may take lessons learned from both and make a third version. My version will also output video and has a PS/2 keyboard connector. I have a version of Tiny Basic that will work with this hardware and this will be my portable computer and game console.
I have, so far, been pretty successful with my creations, even though I have a very rudimentary knowledge of electronics. I know what resistors and capacitors do and an understanding of transistors. More importantly, however, I can read a schematic and everything I’ve done has come from schematics found on the internet. In some cases, I’ve only borrowed parts of the schematic, in other cases, I used a basic schematic from a datasheet (talk about boring) and have put this stuff together on my own. AdaFruit and SparkFun have terrific user forums and they have been a big help as well. But, there is one site in particular: Arduino-Info. This site has code, schematics and really easy to understand explanation about each project. It covers basic things like LCD’s, keypad’s, servo motors and basic Arduino. It explains many electronics concepts and has lots of examples. It has been invaluable.
The Nokia 5110 LCD is a low cost and easy to code panel. It is low res, 84 pixels wide by 48 down. It is challenging (I have an even better appreciation for developers in the ‘70s and early ‘80s) to come up with graphics that look good in such low res. My Mario character looks more like Mega Man. It is a great choice, however, because it has a low memory footprint: 504 bytes for the frame buffer. This still gives about 1.4K to work with, a gold mine. You can get them from AdaFruit or Sparkfun for under ten dollars or on eBay from $1.88 to about $3.00.
That brings me to parts buying. If you buy them on eBay, it will likely be from an overseas vendor. I ordered parts from several Chinese vendors and, in all but one case, I got the items within two weeks and free shipping. I would highly recommend getting them from North American vendors. If you look, you can get pricing that is close to the Chinese vendors and still get free shipping. I got my Mega and one of my UNO’s from vendors located in North America. I had those items in just a few days, so it was worth the extra dollar or two. I also buy from AdaFruit, SparkFun and Jameco. Some things, like the UNO and Mega, cost two to three times the eBay price. I paid ten bucks for the UNO clone and AdaFruit wants $23 and JameCo had one for nearly fifty. Radio Shack sells the UNO for $34.00. As for the Chinese vendors, I bought a bunch of small parts: joysticks, Mini Pro’s, keypads, LCD panels, sensors, etc. The smallest order was $1.88 and the biggest was $16. In all but one case, I got the parts in about two weeks, one took a month and one never arrived, but they did issue a rebate and an apology. I would buy from them again, That was the $1.88 order.
I will post more about my project at a later date
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