The GameTank Is The Latest And Greatest 8-bit Game Console

August 2, 2022 by 15 Comments

The NES, Atari 2600, the Apple II, the Commodore 64 and the TurboGrafx-16 are just some of the many game consoles and home computers built around the 6502 CPU. And while the 6502 has been pretty much obsolete since the mid-’90s, that hasn’t stopped hackers from building new systems with it in the 21st century. Today we can even show you an entirely new 6502-based game console: the GameTank, designed and built by [Clyde Shaffer].

The GameTank was designed to be easy to build by anyone, and is therefore largely constructed from DIP chips that can be bought new at any component distributor. The main CPU is a WD65C02 running at 3.5 MHz, assisted by a 6522 I/O controller and 32 kB of RAM. Composite video is generated by a clever circuit made out of discrete logic chips. The video card comes with DMA for fast transfers and even includes a blitter, which enables it to move images around the screen quickly without loading the CPU.

For the controllers, [Clyde] decided to go for the more-or-less industry standard DE-9 connector gamepads as used on the Sega Genesis and various Atari consoles. He also made his own controller, a 3D printed one with four directional buttons, three action buttons and a start button. The buttons are implemented with Cherry MX Clear switches — an unusual choice for a gamepad perhaps, but they’re apparently very comfortable for long gaming sessions.

The console itself is also housed in a printed enclosure with a design reminiscent of the Nintendo 64. Game cartridges are inserted at the top and contain an EEPROM chip that can be written with a special programmer. The cartridge port also brings out several internal signals and can therefore be used as an expansion port, similar to the way Super NES cartridges could accommodate enhancement chips.

Games currently available include Tetris, the office-themed platformer Cubicle Knight, a Zelda-style adventure named Accursed Fiend, and a remake of the classic viral animation Bad Apple. [Clyde] provides a comprehensive stack of tools and example code and invites anyone interested to help develop more software for the platform. There’s also a hardware-accurate emulator, which is not only useful if you’re writing new code for the system but also if you simply want to try out the existing games in your browser.

Rolling your own 6502 system is great fun, and we’ve seen several examples over the years: some are built with huge bundles of wire, some are come with a clever programming language, some are so tiny they fit on your wrist, and some are simply beautifully made.

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Hoverboard Powered Sofa Is Fun And A Bit Dangerous

August 2, 2022 by 8 Comments

Discarded hoverboards are a great source of free high torque motors for hacking. This can include crazy but fun projects like this hoverboard-driven IKEA sofa, as demonstrated by [Bitluni] and his friends at xHain Hackerspace in Berlin.

With a couple of dead hoverboards in various conditions and a working e-bike battery, the group started exploring different options to put together a usable drivetrain. The first attempt involved commanding the motor drivers directly by intercepting communication from the gyro-based controller. The 9-bit communication protocol was a tough nut to crack, so they tried (and failed) to use the gyro-boards directly as the controllers. In the process of researching they discovered someone had created alternative firmware for the hoverboard controllers to allow control with a Wii Nunchuck. There is even a web-based config tool for compiling the firmware.

With some wood spacers screwed to the bottom of the sofa, the hoverboard motors could be attached by simply screwing their enclosure to the bottom of the couch and adding a section of PVC pipe between the halves for wiring. Caster wheels were added to the rear corners of the sofa to complete the chassis. The motors were very sensitive to control inputs on the Nunchuck, so riding the couch tended to rapidly turn into a rodeo event. The couch also wasn’t made to carry its load on the outer corners, so it had to be reinforced with plywood after it started cracking.

We’ve seen plenty of hacks that involve hoverboard motors, including an electric skateboard with mecanum wheels and a surprisingly practical e-bike conversion.

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Combat Gets A Computer Controlled Opponent

August 1, 2022 by 11 Comments

If you ever spent some time playing on the Atari 2600, there’s an excellent chance you went through a few rounds of Combat. The two-player warfare game not only came with the console but was actually one of the more technically impressive titles for the system, offering nearly 30 variations of the core head-to-head gameplay formula.

But unfortunately, none of those modes included single player. That is, until [Nick Bild] got on the case. While some concessions had to be made, he has succeeded where the original developers failed, and added a computer-controlled enemy to Combat. What’s more, the game still runs on the stock 2600 hardware — no emulator tricks required. The true aficionados can marvel at the snippets of source code he’s provided, but the rest of us can just watch the video below the break and marvel at the accomplishment.

If you’ve never worked on such a constrained system, this might not seem like a big deal. But [Nick] does a great job of explaining not just what he did, but why it was so hard to pull off in the first place. For example, the console has no video buffer, so everything needs to be done during the VBLANK period where the game doesn’t need to be drawing to the screen. Unfortunately that didn’t give him enough free cycles, so he had to split his code up to run across three frames instead of just one. That mean’s the original game logic is now only running 27 frames out of the 30 per second, but he says you can’t really tell in practice.

That said, some cuts had to be made. He needed to remove the surprisingly complex engine sounds to free up some resources, and had to bump the 2 KB cartridge up to 4 KB to hold the new code and data. Turns out the 2600 could handle far larger cartridges via bank switching though, so this wasn’t actually a problem.

Given its age and limited capabilities compared to more modern consoles, you might think the Atari 2600 would be little more than a footnote in gaming history. But there’s a devoted group of folks who enjoy squeezing everything they can out of the system’s 45-year-old hardware which leads to labors of love like this one.

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Never Too Rich Or Thin: Compress Sqlite 80%

August 1, 2022 by 11 Comments

We are big fans of using SQLite for anything of even moderate complexity where you might otherwise use a file. The advantages are numerous, but sometimes you want to be lean on file storage. [Phiresky] has a great answer to that: the sqlite-zstd extension offers transparent row-level compression for SQLite.

There are other options, of course, but as the post mentions, each of these have some drawbacks. However, by compressing each row of a table, you can retain random access without some of the drawbacks of other methods.

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OpenDendrometer Can Measure How Your Tree Feels

August 1, 2022 by 12 Comments

There are various ways to measure plant health, and we’ve seen many projects creating open-source solutions. One we haven’t seen is a dendrometer, which involves measuring various physical dimensions of trees to track their health and growth. [John Opsahl] is changing this with the OpenDendrometer, a tool for tracking the diameter of tree limbs and fruit.

Tiny changes in diameter take place throughout the day, and tracking these changes allows deviations to be detected, which can be a sign of water stress. Over weeks and months, these measurements can be used to measure growth and fruits’ progress to harvest. [John] found that a digital tire tread depth gauge can work well for this application. Many of these gauges use the same electronics as the cheap digital calipers, for which the serial protocol was reverse engineered more than a decade ago. The OpenDendrometer connects the tire depth gauge to a microcontroller via a 1.5V level shifter, which logs measurements to an SD card while using a DS3231 RTC for accurate timestamps. The RTC can also be used to wake up the circuit at the required intervals to save battery power. For the initial proof of concept [John] is using an Arduino Pro Mini, but plans to move to an ESP32 at a later stage to allow wireless data transmission.

Everything will be housed in a 3D printed enclosure with a foam cord gasket to make the device weather resistant. A mounting rod on the outside of the enclosure with adjustable thumbscrews allows the OpenDendrometer to be attached to any part of the tree. We plan to keep an eye on this project and look forward to seeing the data it produces.

For the other ways of measuring plant health, we’ve covered everything from soil moisture to Normalized Difference Vegetation Index and even plant weight and even pot plant weight.

Simple Propulsion For The Lazy Paddle Boarder

August 1, 2022 by 14 Comments

One of the downsides to healthy outdoor activities is all the exercise. Who would want to do that if you can build something to do the hard work for you? That seems to be the theme of [Bitluni]’s latest build, a simple (and hacky) propulsion system for a stand-up paddleboard.

After acquiring an inflatable stand-up paddleboard and trying it out a few times, [Bitluni] decided to skip the “stand up” and “paddle” parts. He designed and printed a very simple propeller, which he intended to power with a brushless motor and speed controller. In the process of drilling out the prop to fit the shaft, he realized he was overcomplicating things. So he decided to just use his battery-powered drill instead. For the shaft tube, he modified an old crutch by drilling a hole in the handle for the shaft and adding a duct with a bearing on the other end. He also attached a carabiner to the handle to fix it to the paddleboard.

A test at a lake showed that the propulsion system performed relatively well for a proof of concept but had some flaws. To submerge it properly, [Bitluni] had to sit on the rear of the paddleboard facing backward. If it was too close to the surface, it would suck air and lose thrust, or spray him and his drill with water. Of course, there is also the real risk of drowning his drill in the process.

Projects don’t need to be complex to be enjoyable, and you can often learn more by quickly creating a proof of concept instead of taking forever to come up with the “perfect” design.

If you want to see some more advanced water-borne projects, check out the waterjet-powered electric surfboards built by [RCLifeOn] and [Andrew W].

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Scavenging CDs For Flexible Parts

August 1, 2022 by 42 Comments

CDs are becoming largely obsolete now, thanks to the speed of the internet and the reliability and low costs of other storage media. To help keep all of this plastic out of the landfills, many have been attempting to find uses for these old discs. One of the more intriguing methods of reprurposing CDs was recently published in Nature, which details a process to harvest and produce flexible biosensors from them.

The process involves exposing the CD to acetone for 90 seconds to loosen the material, then transferring the reflective layer to a plastic tape. From there, various cutting tools can be used to create the correct pattern for the substrate of the biosensor. This has been shown to be a much more cost-effective method to produce this type of material when compared to modern production methods, and can also be performed with readily available parts and supplies as well.

The only downside to this method is that it was only tested out on CDs which used gold as the conducting layer. The much more common aluminum discs were not tested, but it could be possible with some additional research. So, if you have a bunch of CD-Rs laying around, you’re going to need to find something else to do with those instead.

Thanks to [shinwachi] for the tip!