Hacklet 124 Running Robots And The Claw

September 10, 2016 by Adam Fabio 14 Comments

You never know what you’ll find when you open the projects feed on Hackaday.io. Most weeks, The Hacklet follows a theme of some sort. Sometimes I find projects that just look so cool that I have to get the word out about them.

Such is the case with this week’s first project, Mr. Runner created by [Alex Martin]. Mr. Runner is a quadruped robot that really looks the part. In fact, I’d say it looks like it’s ready to jump off the bench top. Like many of us, [Alex] has been inspired by Boston Dynamics, specifically their Wildcat robot. Wildcat had [Alex] searching the net for walking robot designs. He struck up something he liked with the work of [Dr. Fumiya Iida] and [Dr. Rolf Pfiefer]. In the mid 2000’s, the pair worked out of the University of Zurich. Mr. Runner is based upon their work, with plenty of design tweaks from [Alex].

The basic design is a quadruped with two servos per leg. The servos are at the body and the upper half of the leg. The knee and lower leg are connected by levers and a spring, forming something of a 4 bar linkage. The spring acts as a tendon, absorbing shock, and allowing energy from the servo to be stored and released while the robot runs. [Alex] is experimenting with gaits, controlled by a PC.

Mr. Runner wouldn’t be doing much running without a way to control those 8 servos. [Alex] started with an Arduino and a LynxMotion serial servo controller. This pairing served him well for the first generation of Mr. Runner. For the new version of the robot, he’s rolling his own board based upon Lynxmotion’s
BotBoarduino. The Gerber files have been sent off to OSH Park, and in about a week, Mr. Runner will be off to the races.

Another great recently updated project is Arcade Claw Game Claw Build by [Alex Anderson]. I spent way too many hours of my youth in arcades, and more than a few quarters went into claw games. Sure, they’re usually rigged, but who hasn’t been pulled in by the chance to test your skill and win a prize? A friend asked [Alex] to design an arcade style claw for a game. A seasoned CNC and 3D printing master, [Alex] grabbed his notebook and started sketching. Rack and pinion designs would work well, but didn’t within the constraints of the game. A leadscrew based design would also work, but would be two expensive. Finally, [Alex] settled on a design and fired up his CAD software. He started with two jaw systems to prove out the basic system. Once that was complete, [Alex] moved to a 4 jaw setup.

Much like the arcade games, the claw is actuated by a central plunger. The plunger drives linkages which move the 4 claw jaws. Everything looks good on paper, but when the CAD drawings meet the real world, things get complicated quickly. The initial design relied on a 3D printed part which connected the plunger to the jaw linkages. Any slop in this part would be magnified through the rest of the mechanical system. 3D printers aren’t perfect, and there was some slop — enough that the parts would pinch and bind up while moving.

[Alex] already has a revised design in mind. This is very much a work in progress. That’s the beauty of well documented projects on Hackaday.io — you get to see what works, as well as all the trials and tribulations it took to get to a final working project. Keep at it [Alex], you’re almost there!

That’s it for this week’s Hacklet, As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Books You Should Read: Poorly Made In China

September 9, 2016 by Bob Baddeley 110 Comments

This book is scary, and honestly I can’t decide if I should recommend it or not. It’s not a guide, it doesn’t offer solutions, and it’s full of so many cautionary tales and descriptions of tricks and scams that you will wonder how any business gets done in China at all. If you are looking for a reason not to manufacture in China, then this is the book for you.

The author is not involved in the electronics industry. Most of the book describes a single customer in the personal products field (soap, shampoo, lotions, creams, etc.). He does describe other industries, and says that in general most factories in any industry will try the same tricks, and confirms this with experiences from other similar people in his position as local intermediary for foreign importers.

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Review: The RC2014 Z80 Computer

September 8, 2016 by Jenny List 58 Comments

As hackers and makers we are surrounded by accessible computing in an astonishing diversity. From tiny microcontrollers to multi-processor powerhouses, they have become the universal tool of our art. If you consider their architecture though you come to a surprising realisation. It is rare these days to interface directly to a microprocessor bus. Microcontrollers and systems-on-chip have all the functions that were once separate peripherals integrated into their packages, and though larger machines such as your laptop or server have their processor bus exposed you will never touch them as they head into your motherboard’s chipset.

A few decades ago this was definitely not the case. A typical 8-bit microprocessor of the 1970s had an 8-bit data bus, a 16-bit address bus, and a couple of request lines to indicate whether it wanted to talk to memory or an I/O port. Every peripheral you connected to it had to have some logic to decode its address and select it when you wanted to use it, and all shared the processor’s bus. This was how those of us whose first computers were the 8-bit machines of the late 1970s and early 1980s learned the craft of computer hardware, and in a world of Arduino and Raspberry Pi this now seems a lost art.

The subject of today’s review then provides a rare opportunity for the curious hardware hacker to get to grips with a traditional microprocessor bus. The RC2014 is a modular 8-bit computer in which daughter cards containing RAM, ROM, serial interface, clock, and Z80 processor are ranged on a backplane board, allowing complete understanding of and access to the workings of each part of the system. It comes with a ROM BASIC, and interfaces to a host computer through a serial port. There is also an ever-expanding range of further peripheral cards, including ones for digital I/O, LED matrixes, blinkenlights, a Raspberry Pi Zero for use as a VDU, and a small keyboard.

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Hackaday Dictionary: Mux/Demux

September 6, 2016 by Bob Baddeley 16 Comments

In this issue of Hackaday Dictionary, we cover the multiplexer and demultiplexer (also called mux and demux). They are essentially opposites but they work on the same principle. There are three parts: the input, the output, and the selector.

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New Part Day: The ESP32 Has Been Released

September 5, 2016 by Brian Benchoff 92 Comments

A few years ago, a strange little chip showed up on Seeed Studio one day. It was the ESP8266, originally sold as a serial to WiFi adapter. Since then, the microcontroller in this wee WiFi module was discovered, and the ESP8266 has been the breakout module for hundreds of Internet of Thing modules, and other wireless baubles.

The company behind the ESP8266, Espressif, wasn’t sitting on their laurels for the last few years. They’ve been working on a followup to the ESP8266. It’s the ESP32, and it’s faster, has more peripherals, better WiFi, and Bluetooth LE. Since Christmas, we’ve been ogling this chip. Now, it’s finally out. You can buy an ESP32 right now. Consider the ESP32 released.

Almost exactly two years ago, the forerunner of the ESP32 was released, allowing anyone to blink a LED from the Internet for five dollars. There was a catch with the release of the ESP8266, and that was documentation. Documentation in English did not exist, and it took Espressif a while to realize the hit they had on their hands. Even now, with a proper English datasheet from Espressif, we don’t know if the ESP8266 has 5V tolerant pins. Documentation was an issue for the ESP8266, but it didn’t really matter because someone on the Internet figured it out.

History doesn’t repeat itself, but it is the franchise with the most reboots. There’s some documentation for the ESP32, but it’s far from complete. There’s a CAN bus peripheral in the ESP32, but no one knows what pins it’s attached to. There are some secrets hidden away, but no one is at liberty to discuss them. No one outside Espressif has any idea if the specs are real. This will, of course, change in the next month or so, but only due to the tireless work of electronics enthusiasts the world over.

Right now, there are several listings on the usual online outlets including Espressif’s Taobao shop and Seeed Studio offering either bare ESP32 chips or modules based on this WiFi Bluetooth wonder. These modules include the ESP-Wroom-32 (PDF) that is seemingly based on the ESP31 test modules released late last year and the ESP3212, a module based on the popular ESP8266-12. There are also bare chips floating about.

As far as any new information regarding the ESP32 is concerned, don’t expect much. It’s released, though, and in a month or so the work of documenting this supposed wonderchip will begin.

Although they’re not available to everyone quite yet, we have two ESP-32 modules in hand, and [Elliot] is currently slogging through installing the toolchain and getting everything working. Watch this space, because we’re going to have an Introduction to the ESP-32 post up shortly.

Retrotechtacular: Home Video Recording

September 5, 2016 by Al Williams 92 Comments

The news has been full of reports that the last company manufacturing consumer VCRs will cease making them this year. I think most of us are surprised that the event is only happening now. After all, these days, video recording is likely to be on a hard drive, a USB stick, or on a server somewhere. Even recording to DVDs seems a bit quaint these days.

Back before there were web sites, people had to get information from magazines like Popular Electronics, Radio Electronics, and a few others. In the late 1960s and early 1970s, it was common to see these magazines predict that this would be the year of the home video recording system. For example, in 1971, [Lou Garner] wrote: “…they [Sony] hope will put home videotape playing in the same living room as conventional high-fidelity sound systems.” You should know that the video cassette he was talking about was 8 inches wide by 5 inches deep (a big larger than a VHS tape) and contained 3/4 inch magnetic tape (VHS used 1/2 inch tape). The 32-pound player had a retail price of about $350 (about $2,000 in today’s dollars; remember gas was $0.36 a gallon and eggs were $0.53 a dozen). It would be several years before VHS and Betamax would duke it out for home supremacy.

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Hackaday Links: September 4, 2016

September 4, 2016 by Brian Benchoff 28 Comments

Nozzle socks! Just keep saying, ‘nozzle socks’ until the semantic satiation undoes any semblance of sanity. E3D, makers of the world’s finest 3D printer hotends have released silicone nozzle covers that prevent caramelized plastic gunking up your hot end. Nozzle socks.

Let’s talk guitar pedals. If you’ve ever built your own guitar pedal, you probably stuffed it inside a Hammond enclosure. There’s more to guitar pedal enclosures than custom-painted electronic boxes, and arguably the best enclosures are the ‘Boss’ style – a metal cover over the switch that can be removed to access the battery independently of the circuit. Now you can buy this type of enclosure. [Rixen] is producing blank die-cast aluminum pedals that look so much better than the standard Hammond enclosure.

The Antonov AN-225 is the largest and heaviest airplane in the world. Only one was built. For the last thirty years, a second airframe, about 70% complete, has sat in a field or hangar in the Ukraine, waiting for someone to put it into service. After numerous false starts over the past decade or so, the second AN-225 is finally being built.

The Hackaday Retro edition is our version of Hackaday optimized for embedded devices. When someone gets some old hardware on that vast World Wide Web and manages to pull up the retro edition, we like to celebrate. [Michael] recently got his old Amiga 1200 online and managed to find the software and hardware to get this machine on the net. Inside the A1200 is a 4GB CompactFlash, an ACA 1232 accelerator card with 128MB of RAM and a 33MHz 030. The network is handled by a Linksys EC2T card, and the software is KS3.0, WB3.1, MiamiDX IP stack IBrowse 2.4, and a bunch of 3rd party libs he can’t remember. Here’s a pic.

On a related note, I haven’t touched the Hackaday Retro Edition in years. Right now, it’s just a script running every five minutes that assembles five random posts from the first 15,000 Hackaday posts since the beginning of time. The retro edition does what I want it to do, but I’m wondering if it can be better. If you have an idea of how to improve the Retro Edition, leave a note in the comments.