In the past, we have seen many variations of tiny game consoles. Franco Trimboli, aka sunpazed, a maker from Melbourne has shared his own spin on the tiny game console, called Tetromino. As you can guess from the name, it is a tiny Tetris console the size of a keychain. The brain of Tetromino is an ATtiny85 chip from Microchip. For display, sunpazed chooses an easy to find OLED module with a resolution of 128x32. As you can see the design itself is very minimal and only uses a bare minimum of components. Apart from the ATtiny85 and the display the Teromino contains a toggle switch for power, four tactile switches for gameplay, a single resistor and a battery holder. The Teromino is powered by a single 3V CR2032 battery. For programming, he used a number of exposed pads on a side of the PCB in combination with SOP16 programming clip. This a very ingenious way to avoid connectors and to get a reliable connection for programming. In this method, one section of the clip is being in contact with the pads.
The build cost of the Teromino daily is very low, with the entire BOM and board costing less than $10 in total. To accommodate easier soldering sunpazed selected larger surface mount components where possible, and the pads on the board are also wider. Both the hardware and firmware of Teromino are fully open-source. If you are interested in recreating this project, all the necessary files including the PCB design files and the Arduino sketch file can be downloaded from the Teromino GitHub repository along with the instructions.