Chuck peddle father of 6502

Honoring Chuck Peddle; Father Of The 6502 And The Chips That Went With It

December 25, 2019 by 77 Comments

Chuck Peddle, the patriarch of the 6502 microprocessor, died recently. Most people don’t know the effect that he and his team of engineers had on their lives. We often take the world of microprocessor for granted as a commonplace component in computation device, yet there was a time when there were just processors, and they were the size of whole printed circuit boards.

Chuck had the wild idea while working at Motorola that they could shrink the expensive processor board down to an integrated circuit, a chip, and that it would cost much less, tens of dollars instead of ten thousand plus. To hear Chuck talk about it, he got a cease-and-desist letter from the part of Motorola that made their living selling $14,000 processor boards and to knock off all of the noise about a $25 alternative.

In Chuck’s mind this was permission to take his idea, and the engineering team, elsewhere. Chuck and his team started MOS Technologies in the 1970’s in Norristown PA, and re-purposed their work on the Motorola 6800 to become the MOS 6502. Lawsuits followed.

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Need Hackable Melodies? Here’s The TETRIS Theme And More

December 25, 2019 by 3 Comments

[Robson Couto] started to get interested in musical projects and as a side effect created downloadable code with simple notation for a good variety of themes, songs, and melodies. They are all for the Arduino and use only the built-in tone() function, but don’t let that distract you. If you look past that, you’ll see that each sketch is a melody that consists of single notes and durations; easily adapted to other purposes or simply used as-is. After all, [Robson] wanted the source of each tune to be easily understood, easily modified, and to have no external dependencies.

All that may sound a bit like MIDI, but MIDI has much more in common with hardware events than music notation because it includes (among other things) note starts and note ends as separate elements. Converting MIDI into a more usable format was a big part of a project that fed Bach music to a neural network and got surprisingly good results.

When doing music projects, sometimes having a recognizable melody represented very simply as notes and durations with only one note at a time can be an awfully handy resource, and you can find them on GitHub. There’s a brief video of the Tetris theme (actual name: Korobeiniki) being played after the break.

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Team Scores Big Points With Pinball Final Project

December 25, 2019 by 6 Comments

For their final project in [Bruce Land]’s class on designing with PIC32 microcontrollers, [Sujith], [Julia] and [Andrew] wanted to do something fun. And what could be more fun than bending to the electromechanical siren song of the pinball machine?

This machine looks great, and as you can see in the demo video after the break, it plays and sounds great, too. We particularly like the boomerang obstacle and the game state-driven LED strip. The more points you score, the brighter they go. We also like that this machine combines traditional scoring methods with a few really clever ones, like the boomerang target near the top and the scoring triggers made from copper tape.

The team started by designing the heart of any pinball machine, the flippers. Though we have seen car door lock actuators used in homebrew machines, the team went with traditional solenoids to drive them. Unfortunately the solenoids caused a lot of interference, but the team got around it with filter capacitors and aluminium foil Faraday cages around the wires.

If all this pinball talk has your circuits lit up, why not try making your own machine? Continue reading “Team Scores Big Points With Pinball Final Project” →

Arduino Polygraph Shows How It’s Done

December 25, 2019 by 9 Comments

Sometimes, a project comes along that makes a good reference design for anyone doing similar work. In this particular case, it’s a DIY USB polygraph-like machine by [Juangg] using an Arduino and sensors on the hardware side, and a Python front end for data visualization. It’s even complete with 3D printed enclosure and sensor elements.

[Juangg] designed it to use three sensors: a pulse sensor, a breath sensor, and one to measure Galvanic Skin Response (GSR). The pulse sensor uses a piezo element pressed against a fingertip to detect changes in pressure resulting from blood flow. It can be picky about placement, but finding sweet spot can yield remarkably good readings. The breath sensor works on a similar principle but uses a 3D printed fixture to hold the sensor between a strap and the subject’s chest, so that breathing in and out can be detected. The GSR sensor is a voltage divider used to measure small changes in skin conductivity. How well does it all work? That depends on what one is looking to get out of it, but the documentation and design files are available from the project page and the GitHub repository if anyone wants a reference for similar work.

The polygraph may have a mixed reputation, but it makes a good project that demonstrates just how messy biometrics can be from an engineering perspective. And in case you missed it, here’s a reminder that Wonder Woman and the polygraph have much more in common than you might realize.

Laser Welding With A Tattoo Removal Gun

December 25, 2019 by 49 Comments

Dating as far back as the early 1960’s, researchers were zapping tattoo inks with laser light was an effective way to remove the markings from human skin. At the time it was prohibitively expensive. But the desire to have an undo-button for badge choices is strong, and thus the tattoo removal gun was born.

These days you can pick up one of these zappy, burn-y wonders for far less than a flagship cellphone put their high-power-output to alternative use. [Andrew] recently discovered that these devices can be readily repurposed into a laser welding tool with just a bit of work under the hood.

He first came across the technology via videos from [styropyro], whose work we’ve featured before. The tattoo removal gun features a YAG laser, which is pulsed to create a high power density. In initial testing, the pulses were too short and of too high intensity to effectively weld with; instead, the pulses simply cratered the metal.

After delving in further, [Andrew] discovered that by removing the Q-switch optical component, the pulses from the laser could be lengthened. This reduces the power density, and allows the tool to weld various materials even on its lower power settings. Success was found welding steel, titanium, and other materials, though attempts to weld copper and silver faced little success. Test pieces included razor blades and small screws, which could easily be welded with the tool. Results of the razor blade welding is spectacular, with a high-quality welding bead achieved by taping the laser to a CNC mill for precise movement.

It could prove to be a useful tool for those experimenting with complex projects involving bonding metals at very fine scales. If you’re pursuing something exotic yourself, we want to hear about it!

Color Coded Clock Runs On Roman Numerals

December 24, 2019 by 2 Comments

Roman numerals are, by modern standards, a bit unusual. By virtue of using designations for both 5 and 10, and not scaling well to higher numbers, they’ve fallen out of favor outside of some specific uses. One of those is in time keeping, in which many clocks use the classical numerals instead of the more popular Arabic replacements. [Nicola]’s clock does too, albeit in a rather unusual way.

A diagram of the clock displaying the times 18:40 and 23:04.

The build begins with a faux-neon palm tree LED decoration, which is gutted and refitted with a WS2812B LED strip, run by an Arduino Nano. An RTC is used to keep accurate time, and the time is set by running a one-off program to initialise the clock.

To tell the time, the LEDs are color coded. However, instead of using a binary representation that many can find unfamiliar, colors are chosen instead to correspond to Roman numerals. Blue, green, red and yellow are chosen to represent 1, 5, 10, and 50, or I, V, X, and L respectively. The Github has more details for the curious. The clock uses 24 hour time, and we think we’ve figured out how the display works – with hours on the left and minutes on the right.

It’s fun to see an LED clock that takes a different bent on the usual themes. We’ve seen plenty over the years, from the byte clock to this stunning blinkenlights build. If you’ve cooked up your own special timepiece, be sure to let us know.

LuaRadio Gives Insight Into SDR

December 24, 2019 by 3 Comments

In theory, you shouldn’t need any help to develop a software-defined radio (SDR) application. But in real life you really don’t want to roll your own code every time to read the IQ samples, perform various transformations on them, and then drive audio output. At worst, you’ll use some libraries (perhaps GNU Radio) but usually, you’ll use some higher-level construct such as GNU Radio Companion (GRC). GRC is a bit heavyweight, though, so if you’ve found it daunting before, you might check out some of the material on the LuaRadio website.

We’ve looked at LuaRadio several years ago, but it has undergone a lot of changes since then and has some excellent documentation. Like Lua itself, LuaRadio emphasizes fast scripting. It supports quite a few pieces of common hardware and nearly anything that feeds data through a soundcard.

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