Data Logging Like It’s 1982

July 26, 2018 by 26 Comments

If you want to log voltages or resistance these days, no problem. You can buy a multimeter with Bluetooth for a hundred bucks, and if you’re really fancy you can spring for the Fluke with a graphical display that will log values automatically. Things weren’t always this cheap and easy, but there was always a way to do it.

Back in the 80s, HP had GPIB, or HP-IB, or IEEE-488 connectors on the back of their benchtop equipment. This was an 8-bit interface not unlike a parallel port that allowed for remote control of test equipment. In a great demonstration of what this was actually like, [AkBKukU] posted a video of connecting an old benchtop multimeter to a vintage computer over GPIB.

The computer used for this feat of retrotechtacularness is an HP Series 80, a footnote in the history of desktop computers, but it does have a custom CPU and BASIC in ROM. As you would expect from vintage HP gear, there are a few slots on the back of the computer for connecting interface boxes, including a modem, a speech synthesizer, and of course, an HP-IB interface that can speak IEEE-488.

With the multimeter connected to the computer over the daisy-chainable parallel interface, it was a simple matter of writing a little bit of BASIC to read a potentiometer and a thermistor. With a little bit more code, this computer can even produce a graph of the resistance over time. This is data logging like it’s 1982, and it’s a fantastic example of exactly how far we’ve come.

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Talking To Alexa With Sign Language

July 25, 2018 by 19 Comments

As William Gibson once noted, the future is already here, it just isn’t equally distributed. That’s especially true for those of us with disabilities. [Abishek Singh] wanted to do something about that, so he created a way for the hearing-impaired to use Amazon’s Alexa voice service. He did this using a TensorFlow deep learning network to convert American Sign Language (ASL) to speech and a speech-to-text converter to interpret the response. This all runs on a laptop, so it should work with any voice interface with a bit of tweaking. In particular, [Abishek] seems to have created a custom bit of ASL to trigger Alexa. Perhaps the next step would be to use a robotic arm to create the output directly in ASL and cut out the Echo device completely? [Abishek] has not released the code for this project yet, but he has released the code for other projects, such as Peeqo, the robot that responds with GIFs.

[Via FlowingData and [Belg4mit]]

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GTA: San Andreas Radio Earns Six-Star Wanted Level

July 25, 2018 by 14 Comments

[Raphaël Yancey] wanted to be able to jam to Bounce FM and Radio:X all the time, without having to steal a car or a street sweeper in San Andreas. As people who like to put on the sad piano building music from The Sims and write Hackaday posts, we can totally relate.

But this isn’t just another one of those jam-a-Pi-into-a-vintage-radio-and-call-it-a-sandwich projects (not that there’s anything wrong with those). This thing acts like a real radio. All the stations play continuously whether you’re tuned in or not, and they bleed into each other as you go up and down the dial.

After much trial and error, [Raphaël] found a Python mixer that would work, but it was no longer maintained. He forked it, squashed a bug or two, and wrote a module for KY040 rotary encoders to make them play nice with the Pi. The snake charming doesn’t stop there: the rock star of this project is [Raphaël]’s virtual radio software, which handles the audio blending as he tunes between stations. A step-by-step tutorial is coming soon, so watch [Raphaël]’s site for updates. Tune past the break to give it a listen.

Adventures in Raspi radio-ing don’t have to be one-way. Here’s how you can turn one into an AM/FM+ transmitter using a DVB-T dongle and SDR.

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Juggling Machine Listens To The Bounce To Keep Ball In The Air

July 25, 2018 by 10 Comments

It’s a seemingly simple task: bounce a ping-pong ball on a wooden paddle. So simple that almost anyone can pick up a ball and a paddle and make a reasonable job of it. Now, close your eyes and try to do it just by the sound the ball makes when it hits the paddle. That’s a little tougher, but this stepper-driven platform juggler manages it with aplomb.

That’s not to say that the path to the finished product in the video below was a smooth one for [tkuhn]. He went through multiple iterations over the last two years, including a version that surrounded the juggling platform with a fence of phototransistors to track where the ball was at any time. That drove four stepper motors through a cross-linkage that popped the platform up at just the right moment to keep the ball moving, and at just the right angle to nudge it back toward the center of the platform. The current version of the platform does away with the optical sensors in favor of four small microphones. The mics pick up the sharp, well-defined sound of the ball hitting the platform, process the signal through an analog circuit, and use that signal to trigger a flip-flop if the signal exceeds a setpoint. An Arduino then measures the time delay between arriving signals, calculates the ball’s position on the platform, and drives the steppers through a PID loop to issue the corrective bounce.

The video below is entrancing, but we found ourselves wishing for a side view of the action too. It’s an impressive build nonetheless, one that reminds us of the many maze-runner and Stewart platform robots we’ve seen.

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ESP8266 Zelda Heart Responds To Tweets

July 25, 2018 by 3 Comments

It might not be enough to make you the Hero of Time, but this piece of Hylian interactive art would still be a worthy addition to your game room. [Jeremy Cook] writes in to tell us about how he put together this 8-bit style heart display, and goes into enough detail on the hardware and software sides of things that you shouldn’t have any problem adapting his design for your own purposes.

The build is pretty simple overall but it does assume you have a CNC to cut the basic shape out of MDF. You could cut the shape by hand if you had to, but if you don’t have a CNC the next best thing might be to 3D print the case. You’d potentially have to print it in two parts right down the center though, depending on how big your bed is. Whichever way you create the case, you’ll then need to cut the shape out of a piece of acrylic to make the face.

In any event, once the pieces are cut out [Jeremy] adds in a Wemos D1 Mini, a power supply, and some red LED strips. He provides a wiring diagram, but it’s fairly straightforward stuff. With a couple of 2N2222 transistors he controls the LED strips right from the digital pins of the ESP8266.

The software side is setup to be controlled via IFTTT by way of Adafruit.io. When IFTTT sees one of the keywords on Twitter, it passes a message to Adafruit.io which ultimately talks to the ESP8266 and gets the heart going. The software supports three states (on, off, and half) and gives a good example of a basic IoT implementation on the ESP8266 if you’re looking for some inspiration.

This hack seems like it would fit in perfectly with the Zelda home automation project we covered last year.

An Integrated Electromagnetic Lifting Module For Robots

July 25, 2018 by 7 Comments

The usual way a robot moves an object is by grabbing it with a gripper or using suction, but [Mile] believes that electromagnets offer a lot of advantages that are worth exploring, and has designed the ELM (Electromagnetic Lifting Module) in order to make experimenting with electromagnetic effectors more accessible. The ELM is much more than just a breakout board for an electromagnet; [Mile] has put a lot of work into making a module that is easy to interface with and use. ELM integrates a proximity sensor, power management, and LED lighting as well as 3D models for vertical or horizontal mounting. Early tests show that 220 mW are required to lift a 1 kg load, but it may be possible to manage power more efficiently by dynamically adjusting drive voltage depending on the actual load.

[Mile]’s focus on creating an easy to use, integrated solution that can be implemented easily by others is wonderful to see, and makes the ELM a great entry for The Hackaday Prize.

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HOPE XII: A FOSS Operating System For E-Readers

July 25, 2018 by 77 Comments

Free and open source software (FOSS) was a recurring theme during many of the talks during the HOPE XII conference, which should probably come as no surprise. Hackers aren’t big fans of being monitored by faceless corporate overlords or being told what they can and cannot do on the hardware they purchased. Replacing proprietary software with FOSS alternatives is a way to put control back into the hands of the user, so naturally many of the talks pushed the idea.

In most cases that took the form of advising you to move your Windows or Mac OS computer over to a more open operating system such as GNU/Linux. Sound advice if you’re looking for software freedom, but it’s a bit quaint to limit such thinking to the desktop in 2018. We increasingly depend on mobile computing devices, and more often than not those are locked down hard with not only a closed proprietary operating system but also a “Walled Garden” style content delivery system. What’s the point of running all FOSS software at home on your desktop if you’re carrying a proprietary mobile device around?

That’s precisely the thinking that got Marc Juul interested in the possibility of bringing a FOSS operating system to e-reader devices. During his talk “Liberate Your E-book Reader with fread.ink!”, he gave examples such as Amazon’s infamous remote deletion of 1984 off of users’ Kindles as a perfect example of the sort of control these companies exert on our personal devices. Marc believes the goal should be to completely replace the operating system on these devices with a free software alternative that still retains the ability to open electronic book formats. Not only would this keep the likes of Amazon or Barnes and Noble out of our reading habits, but turn these cheap readers into more capable devices in the bargain.

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