atmega328p

56 Articles

Arduino Engine Runs Many Games

October 26, 2026 by 4 Comments

A few years ago, [Smashcat] ported a ZX Spectrum game called Manic Miner to the Arduino Uno. The Arduino has less memory than the original Spectrum did, so doing all this on an 8-bit microcontroller was no easy lift. Since then, parts of this original port have been adapted to produce a game engine, allowing [Smashcat] to port several other games to the Arduino Uno as well.

The engine is able to host a 2D map with the ability to scroll, at a resolution of 256×256, as well as up to nine sprites at the same time. The graphics are locked to 50 FPS, but only with a real Arduino Uno that has a crystal oscillator. Some replica boards do not have a timekeeping chip accurate enough to replicate the video signal, which is done without a framebuffer. That signal, as well as two PWM audio channels, are still generated directly as well, with only a few resistors needed to hook everything up to a monitor and a controller, including the option of using an NES controller.

With all of that running on the Arduino and it hooked up to the daughterboard that provides the controller interface as well as the resistors for the video signal to function and a driver for a speaker, the system now runs the original Manic Miner as well as three other games: Scramble, Space Invaders, and Pac Man.

The engine and the rest of the code are available on a GitHub page as well, and there’s even a WebAssembly version available to run various pieces of the software without the specific hardware. The original ZX Spectrum was an interesting machine too that still inspires builds like this, despite it being well over 40 years old now.

Lightcomposer

LightComposer – Reach Out And Touch Your Lighting

June 22, 2026 by 5 Comments

While there is a time and place for wirelessly controlled devices, sometimes you want something you can just reach out and touch to interact with, no apps to install or devices to configure. In this case [John] wanted a lamp that was just that. Drawing inspiration from the rotary phone, he created the LightComposer.

This small lamp, just a bit smaller than a hockey puck, uses a 3D printed enclosure and a straightforward PCB. It’s a very accessible project to recreate. The 3D prints are well thought out including a TPU ring on the bottom to keep the lamp from sliding around. The light source comes from 32 SK6812 LEDs, which are very similar to NeoPixels. An ATmega328P microcontroller powers the project and can easily be programmed using the Arduino IDE. A rotary encoder in the center, coupled to the top diffuser, lets you control LED brightness and color by turning it. The firmware also includes some fun hidden light-effect modes.

Head over to [John]’s site for all the files needed to make your own LightComposer, or links to buy a premade one. What devices have you made that use a straightforward physical user interface in lieu of an app? Be sure to check some of the other lamp builds we’ve featured before.

The Joy Of Making Handheld Tetris From Scratch

February 19, 2026 by 4 Comments

As anyone who’s made a thing knows, a lot of work goes into bringing something from idea to completion. But there’s also considerable satisfaction in the process. [Willian] recently did exactly that, and shares the joyful experience of creating a homebrew handheld game gadget from scratch. It runs a homebrewed Tetris clone (as well as Snake), and we love the results.

The game gadget uses an ATmega328P programmed via the Arduino IDE, and a 1.8″ TFT color LCD screen. It’s self-contained in a box with a few buttons as controls and runs off three AAA cells. [Willian] made the smart design choice to run the microcontroller at 8 MHz instead of the more common 16 MHz, because doing so meant the board can run at 3.3 V instead of 5 V. Why does this matter? The LCD display runs off 3.3 V as well, and if all components can run off the same supply and logic levels, it simplifies things considerably.

Also, creating a 3.3 V supply is a simple matter of three alkaline cells in series with an LDO (low drop-out) regulator, which is great for a handheld device. We do note that AA cells have a considerably higher energy density and capacity than AAA cells and are usually the better choice, but one works with what one has, and sometimes the space and weight saved by AAA is just too good to pass up.

The software has some notable approaches to keep things responsive and optimal. Instead of defining each of the Tetris pieces as a 2D shape, [Willian] instead pre-defines each piece (and their rotations) so that rotating a piece is just an index change in an array, instead of a transform implementing a rotation. Also, full-screen redraws are comparatively slow over SPI and caused flickering, so only cells that have changed are redrawn to the screen to keep things responsive. The code is all on GitHub, and it’s a great peek at how things get implemented under the hood.

The enclosure is just cardboard, and it does the job in [Willian]’s case. But we’ll point out that cardboard is actually a highly adaptable material from which to prototype. With just a few tips and a little care, paper products can be your new best friend when it comes to one-offs and prototypes.

A LoRa Rain Gauge From The Ground Up

December 26, 2024 by 4 Comments

It’s a fair bet that most of us have a ton of wireless doo-dads around the house, from garage door remotes to wireless thermometers. Each of these gadgets seems to have its own idea about how to encode data and transmit it, all those dedicated receivers seem wasteful. Wouldn’t it be great to use existing RF infrastructure to connect your wireless stuff?

[Malte Pöggel] thinks so, and this LoRa rain gauge is the result. The build starts with a commercially available rain transmitter, easily found on the cheap as an accessory for a wireless weather station and already equipped with an ISM band transmitter. The rain-collection funnel and tipping-bucket mechanism were perfectly usable, and the space vacated by the existing circuit boards left plenty of room to play, not to mention a perfectly usable battery compartment. [Malte] used an ATmega328P microcontroller to count the tipping of the bucket, either through the original reed switch or via Hall Effect or magnetoresistive sensors. An RFM95W LoRa module takes care of connecting into [Malte]’s LoRaWAN gateway, and there’s an option to add a barometric pressure and temperature sensor, either by adding the BMP280 chip directly to the board or by adding a cheap I2C module, for those who don’t relish SMD soldering.

[Malte] put a lot of work into power optimization, and it shows. A pair of AA batteries should last at least three years, and the range is up to a kilometer—far more than the original ISM connection could have managed. Sure, this could have been accomplished with a LoRa module and some jumper wires, but this looks like a fantastic way to get your feet wet in LoRa design. You could even print your own tipping bucket collector and modify the electronics if you wanted.

Very Tiny Cube Has 384 RGB LEDs

October 1, 2024 by 2 Comments

When it comes to making things that glow, there are two ways to stand out from the crowd. You can make something very big, or something very small. [DIY GUY Chris] has done the latter, producing a tiny LED cube that he says is the world’s smallest.

As is so often the way, the build relies on tiny WS2812B-compatible LEDs in a 1 mm x 1 mm form factor. They’re mounted on a series of teeny interlocking PCBs that come together to build a cube that’s just 8 cubic centimeters in volume. Power is courtesy of a small lithium-ion cell that lives inside the cube. Data and power signals flow around the cube via solder connections along the edges of the faces of the cube.  Running the show is an ATmega328P, the same microcontroller you’d find in an Arduino Uno. It’s responsible for sending out commands to the LEDs to create various animations.

We can’t speak to [Chris’s] claim about being the world’s smallest, but it is small. We’ve seen other builds in a similar vein, like this barely-larger D20 with a full 2400 LEDs, though. Video after the break.

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A Cheap DIY PLC Based On The Atmega328P

August 22, 2024 by 42 Comments

If you’re running a big factory, you’ve probably got a massively expensive contract with a major programmable logic controller (PLC) manufacturer. One shudders to think about the cost of the service subscription on that one. If you’re working on a smaller scale, though, you might consider a DIY PLC like this one from [Mr Innovative.]

PLCs are rarely cutting-edge; instead, they’re about reliability and compliance with common industry standards. To that end, this design features the ATmega328P. Few other microcontrollers are as well understood or trusted as that one. The device is compatible with RS232 and RS485 and will run off 24 VDC, both of which you would find in a typical industrial environment. It offers 24 V digital inputs and outputs, as well as analog inputs and outputs from 0 to 10 V. [Mr Innovative] demonstrates it by hooking up a DWIN human-machine interface (HMI) for, well… human interaction, and a variable frequency drive to run a motor.

If you want to run a basic industrial-lite system but can’t afford the real industrial price tag, you might enjoy tinkering around at this level first. It could be a great way to get a simple project up and running without breaking the bank. Video after the break.

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A PCB business card that plays tic-tac-toe with red and blue LEDs.

2024 Business Card Challenge: Go Tic-Tac-Toe-to-Toe With Them

June 24, 2024 by 4 Comments

There is perhaps no more important time to have a business card than when you’re in college, especially near the end when you’re applying for internships and such. And it’s vital that you stand out from the crowd somehow. To that end, Electrical & Computer Engineer [Ryan Chan] designed a tidy card that plays tic-tac-toe.

Instead of X and O, the players are indicated by blue and red LEDs. Rather than having a button at every position, there is one big control button that gets pressed repeatedly until your LED is in the desired position, and then you press and hold to set it and switch control to the other player. In addition to two-player mode, the recipient of your card can also play alone against the ATMega.

The brains of this operation is an ATMega328P-AU with the Arduino UNO bootloader for ease of programming. Schematic and code are available if you want to make your own, but we suggest implementing some type of changes to make it your own. Speaking of, [Ryan]  has several next steps in mind, including charlieplexing the LEDs, using either USB-C or a coin cell for power, upgrading the AI, and replacing the control button with a capacitive pad or two. Be sure to check it out in action in the two videos after the break.

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