An ATTiny85 based handheld game

Yes, I love gaming.  And there is nothing more satisfying, to me, than building, sometimes coding and playing something I made.  Now, I don’t always WRITE the code, after all, time is a premium these days, but I don’t mind taking something someone else did and making it work with what I built.  For this project, I was very lazy: the design is also someone else’s.  I really wanted to do something with the ATTiny85, but have not really done anything outside of playing with the Adafruit Trinket or Digispark.

So, for this little project, I wanted to also use one of my cool little ssd1306 OLED screens.  While perusing the net, I came across Webboggles.com.  Here, they are selling a nifty little kit called the ATTiny Arcade Keychain. It looks to be of high quality and the author (Ilya Titov) goes through much detail in the design and build.  There are several posts about it and the games.  The game code and schematic have been made readily available. The first of the games was breakout and that is where I started. 

To build the little game, you will need the following:

Attiny85 + dip8 socket

SSD1306 OLED screen

3x push buttons

2x resistors (10kOhm optimal)

Piezo speaker

3V 2032 coin cell battery

perf or vero board

I used a little speaker out of a toy cell phone instead of the piezo. I would also recommend socketing the screen instead of soldering it directly, you don’t have to, but I wish I had now.

One other thing to keep in mind, you will need a way to program the ATtiny 85 chip, which I will describe in a follow up post. I actually built two programmers: one on breadboard and a quasi shield for the UNO.  I like that better.

As you can see from the schematic, it is really simple. Even so, I made a few mistakes at first.  Not paying attention to the chip pinout, I got the pins reversed from pin 8 to pin 5. I, for whatever the reason, assumed the actual pin 8 was pin 5, instead of going from pin 4 to pin 5 at the bottom of the chip. Once I figured that out (I had yet to apply power) the rest was easy. I also got SCL and SDA backward (hey, I’m old).  Once I got my mistakes corrected, I was amazed that this simple circuit was now a little game machine.  Now, you aren’t going to play Call of Duty or even Doom, but you can play many classics on the devices.  I am going to build one or two more as this was a blast. I would also encourage ordering a kit from Webboggles as well.

My next post will discuss creating an Attiny 85 programmer for the UNO.