Adventures In Small Screen Video

March 12, 2016 by Kristina Panos 13 Comments

[Kevin] wanted to make something using a small CRT, maybe an oscilloscope clock or something similar. He thought he scored big with a portable black and white TV that someone threw away, but it wouldn’t power on. Once opened, he thought he found the culprit—a couple of crusty, popped capacitors. [Kevin] ordered some new ones and played with the Arduino TVout code while he waited.

The caps arrived, but the little TV still wouldn’t chooch. Closer inspection revealed that someone had been there before him and ripped out some JST-connected components. Undaunted, [Kevin] went looking for a new CRT and found a vintage JVC camcorder viewfinder on the electronic bay with a 1-1/8″ screen.

At this point, he knew he wanted to display the time, date, and temperature. He figured out how the viewfinder CRT is wired, correctly assuming that the lone shielded wire is meant for composite video. It worked, but the image was backwards and off-center. No problem, just a matter of tracing out the horizontal and vertical deflection wires, swapping the horizontal ones, and nudging a few pixels in the code. Now he just has to spin a PCB, build an enclosure, and roll his own font.

[Kevin]’s CRT is pretty small, but it’s got to be easier on the eyes than the tiniest video game system.

DIY Virtual Reality Snowboard

March 11, 2016 by James Hobson 4 Comments

If you’re looking for a quick and easy project to get into virtual reality, making your own VR skateboard controller is actually pretty easy to do!

First you’ll need some kind of VR headset. You could buy a fancy one, like the Oculus, or a Samsung Gear VR — or you could use something as simple as Google Cardboard — and you could even make your own. All it takes is a phone, an Arduino, a Bluetooth module, and an accelerometer-plus-gyroscope IMU.

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App Control With Ease Using Blynk

March 10, 2016 by Gerrit Coetzee 33 Comments

App development is not fun for everyone, and sometimes you just want to control a device from your phone with minimal work. Blynk appears to be a fairly put-together library for not only hooking up any Arduino or esp8266 to a phone through WiFi, but also through the net if desired.

Install the app onto your iPhone or Android device. Install the libraries on your computer. Next, modify your Arduino source to either pass direct control of a pin to Blynk, or connect Blynk to a virtual pin inside your code for more advanced control. If you want to go the easy route, create an account, log into the app, and drag and drop the interface you’d like. If the idea of letting some corporation host your Arduino project sends shivers down your spine, there is also an option to host your own server. (Editorial snark: Yes, it requires a server. That’s the cost of “simplicity”.)

There have been a few times where we’ve wished we could add app control to our projects, but installing all the libraries and learning a new language just to see a button on a screen didn’t seem worth it. This is a great solution. Have any of you had experience using it?

Mein Enigma

March 9, 2016 by Jenny List 31 Comments

The World War II German Enigma encoding machine is something of an icon in engineering circles not just for its mechanical ingenuity but for the work of the wartime staff at Bletchley Park in decoding its messages. Without it we would not have had Colossus, the first programmable digital electronic computer, and subsequent technological developments might have taken a slower pace towards what we take for granted today.

Sadly for the Enigma enthusiast though, real machines are now few and far between. Our grandparents’ generation saw to that through the chaos and bombing of the fight across Europe. If you want to handle one you will have to either have an outrageous amount of money, work for a museum, or maybe for the GCHQ archivist.

This has not stopped our community building Enigma replicas, and the latest one to come to our attention here at Hackaday shows some promise. [lpaseen]’s meinEnigma is an electronic Enigma driven by an Arduino Nano, with rotary encoders to represent the Enigma rotors and multi-segment alphanumeric displays standing in for the lighted letters in the original. It supports all the different variations of rotors from the original in software, has a physical plugboard, and a serial port over USB through which all machine functions can be controlled. The machine as it stands is a fully working prototype, the plan is that a final machine will resemble the original as closely as possible.

All the code used in the project can be found on GitHub, along with [lpaseen]’s Arduino library for the Holtek HT16K33 keyboard/display chip used to handle those tasks.

We’ve featured a few Enigma machines on Hackaday over the years. One was built into a wristwatch, another into a hacked child’s toy, but the closest in aim to [lpaseen]’s offering is this rather attractive replica also driven by an Arduino. It is also worth mentioning that should your travels ever take you to Buckinghamshire you can visit the Bletchley Park Museum and neighboring National Museum of Computing, to get the Enigma and Colossus story from the source.

Does The World Need An FPGA Arduino?

March 9, 2016 by Elliot Williams 83 Comments

What would you get it you mashed up an FPGA and an Arduino? An FPGA development board with far too few output pins? Or a board in the form-factor of Arduino that’s impossible to program?

Fortunately, the ICEZUM Alhambra looks like it’s avoided these pitfalls, at least for the most part. It’s based on the Lattice iCE40 FPGA, which we’ve covered previously a number of times because of its cheap development boards and open-source development flow. Indeed, we were wondering what the BQ folks were up to when they were working on an easy-to-use GUI for the FPGA family. Now we know — it’s the support software for an FPGA “Arduino”.

The Alhambra board itself looks to be Arduino-compatible, with the horrible gap between the rows on the left-hand-side and all, so it will work with your existing shields. But they’ve also doubled them with pinheaders in a more hacker-friendly layout: SVG — signal, voltage, ground. This is great for attaching small, powered sensors using a three-wire cable like the one that you use for servos. (Hackaday.io has two Arduino clones using SVG pinouts: in SMT and DIP formats.)

The iCE40 FPGA has 144 pins, so you’re probably asking yourself where they all end up, and frankly, so are we. There are eight user LEDs on the board, plus the 28 I/O pins that end in pinheaders. That leaves around a hundred potential I/Os unaccounted-for. One of the main attractions of FPGAs in our book is the tremendous availability of fast I/Os. Still, it’s more I/O than you get on a plain-vanilla Arduino, so we’re not complaining too loudly. Sometimes simplicity is a virtue. Everything’s up on GitHub, but not yet ported to KiCad, so you can tweak the hardware if you’ve got a copy of Altium.

We’ve been seeing FPGA projects popping up all over, and with the open-source toolchains making them more accessible, we wonder if they will get mainstreamed; the lure of reconfigurable hardware is just so strong. Putting an FPGA into an Arduino-compatible form-factor and backing it with an open GUI is an interesting idea. This project is clearly in its very early stages, but we can’t wait to see how it shakes out. If anyone gets their hands on these boards, let us know, OK?

Thanks [RS] for the tip!

Monitor A Serial Port From Anywhere

March 7, 2016 by Gerrit Coetzee 33 Comments

This simple WiFi serial port monitor would have saved us a lot of trouble. We can’t count how many times where being hooked into an Arduino with USB just to get the serial out has nearly been more trouble than it’s worth. Times where we sat cross-legged on the floor and could choose comfort or accidentally shifting the set-up and ruining everything, but not both.

[Frenky]’s set-up is simple and clever. The Ardunio’s serial out is hooked to an ESP8266. The Arduino spams serial out to the ESP8266 in its usual way. The ESP8266 then pipes all that out to a simple JavaScript webpage. Connect to the ESP8266’s IP with any device in your house, and get a live stream of all the serial data. Neat.

As simple as this technique is, we can see ourselves making a neat little box with TX, RX, GND, and VCC screw terminals to free us from the nightmare of tethering on concrete floors just for a simple test. Video after the break.

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Fail Of The Week: Battery Pack Jack Wired Backwards

March 6, 2016 by Rud Merriam 49 Comments

Last Saturday I had a team of teenage hackers over to build Arduino line-following robots from a kit. Everything went well with the mechanical assembly and putting all the wires on the correct pins. The first test was to check that the motors were moving in the proper direction. I’d written an Arduino program to test this. The first boy’s robot worked fine except for swapping one set of motor leads. That was anticipated because you cannot be totally sure ahead of time which way the motors are going to run.

The motor’s on the second robot didn’t turn at all. As I checked the wiring I smelled the dreaded hot electronics smell but I didn’t see any smoke. I quickly pulled the battery jack from the Arduino and – WOW! – the wires were hot. That didn’t bode well. I checked and the batteries were in the right way. A comparison with another pack showed the wires going into the pack were positioned properly. I plugged in another pack but the motors still didn’t run.

I got my multimeter, checked the voltage on the jack, and it was -5.97 V from center connector to the barrel. The other pack read 6.2 V. I had a spare board and pack so swapped those and the robot worked fine. Clearly the reverse polarity had zapped the motor control ICs. After that everyone had a good time running the robots on a course I’d laid out and went home pleased with their robots.

Wires going into pack were correct.

Shaved jack showing positive lead on outside of jack.

After they left I used the ohmmeter to check the battery pack and found the wiring was backwards, as you can see in the feature photo. A close inspection showed the wire with a white line, typically indicating positive, indeed went to the positive battery terminal. I shaved the barrel connector down to the wires and the white line wire was connected to the outside of the barrel. FAIL!

This is a particularly bad fail on the part of the battery pack supplier because how hard is it to mess up two wires? You can’t really fault the robot kit vendor because who would expect a battery pack to be bad? The vendor is sending me a new battery pack and board so I’m satisfied. Why did I have an extra board and pack, actually an entire kit? For this exact reason; something was bound to go wrong. Although what I had imagined was for one of the students to break a mechanical part or change wiring and zap something. Instead, we were faced with a self-destructing kit. Prudence paid off.