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Hackaday Links: July 5, 2015

July 5, 2015 by 28 Comments

It’s the fifth of July. What should that mean? Videos on YouTube of quadcopters flying into fireworks displays. Surprisingly, there are none. If you find one, put it up in the comments.

The original PlayStation was a Nintendo/Sony collaboration. This week, some random dude found a prototype in his attic. People were offering him tens of thousands of dollars on the reddit thread, while smarter people said he should lend it to MAME and homebrewer/reverse engineer groups. This was called out as a fake by [Vadu Amka], one of the Internet’s highly skilled console modders. This statement was sort of semi retracted. There’s a lot of bromide staining on that Nintendo PlayStation, though, and if it’s a fake, the faker deserves thousands of dollars. Now just dump the ROMs and reverse engineer the thing.

Remember BattleBots? It’s back. These are my impressions of the first two episodes: Flamethrowers are relatively common now, ‘parasitic bots’ – small, auxilliary bots fighting alongside the ‘main’ bot are now allowed. KOs only count for the ‘main’ bot. Give it a few more seasons and every bot will be a wedge. One of the hosts is an UFC fighter, which is weird, but not as weird as actually knowing some of the people competing.

Ceci n’est pas un Arduino, which means it’s from the SRL camp. No, wait. It’s a crowdfunding campaign for AS200 Industries in Providence, RI.

Wanna look incredibly sketchy? Weld (or braze, or solder) your keys to a screwdriver.

The UK’s National Museum of Computing  is looking for some people to help maintain 80 BBC Micros. The museum has a ‘classroom’ of BBC micro computers still in operation. Caps dry out, switching power supplies fail, and over the years these computers start to die. If you have the skills and want to volunteer, give it a shot.

USA-made Arduinos are now shipping. That’s the Massimo Arduino, by the way.

Win $1000 for pressing a button. We’re gauranteed to give away a thousand dollar gift card for the Hackaday store next Wednesday to someone who has participated in the latest round of community voting for the Hackaday Prize.

Rotary Indexer Gives Mill A 4th Axis (sort Of)

July 4, 2015 by 23 Comments

Rotary indexer’s are standard issue in most machine shops. These allow you to hold or chuck a work piece, and then a graduated handle lets you to rotate the workpiece. Useful when you want to drill or tap axial or radial features. A rack and pinion drive ensures that the workpiece does not move under machining load. Quite often, these indexers also have a manual lock to take care of gear backlash and play. Automating them is not too difficult either. You could use just a stepper motor (open loop) or servo+encoder (closed loop) to drive the turntable.

[smashedagainst] needed to drill six radial holes on a part. And he had to do it on 500 pieces for a total of 3000 holes. That was just for the first initial run, with more drilling likely in the future. The part in question was small and light weight. So instead of using a heavy duty, industrial grade unit, he built an all-electric rotary indexing jig using a stepper motor and an Arduino, giving him a sort of rotary 4th axis. His idea was to directly use the stepper motor to rotate the workpiece without any gearing, but he needed to build his own rig to do so.

Continue reading “Rotary Indexer Gives Mill A 4th Axis (sort Of)” →

Instrument Cluster Clock Gets The Show On The Road

July 3, 2015 by 24 Comments

While driving around one day, [Esko] noticed that the numbers and dials on a speedometer would be a pretty great medium for a clock build. This was his first project using a microcontroller, and with no time to lose he got his hands on the instrument cluster from a Fiat and used it to make a very unique timepiece.

The instrument cluster he chose was from a diesel Fiat Stilo, which [Esko] chose because the tachometer on the diesel version suited his timekeeping needs almost exactly. The speedometer measures almost all the way to 240 kph which works well for a 24-hour clock too. With the major part sourced, he found an Arduino clone and hit the road (figuratively speaking). A major focus of this project was getting the CAN bus signals sorted out. It helped that the Arduino clone he found had this functionality built-in (and ended up being cheaper than a real Arduino and shield) but he still had quite a bit of difficulty figuring out all of the signals.

In the end he got everything working, using a built-in servo motor in the cluster to make a “ticking” sound for seconds, and using the fuel gauge to keep track of the minutes. [Esko] also donated it to a local car museum when he finished so that others can enjoy this unique timepiece. Be sure to check out the video below to see this clock in action, and if you’re looking for other uses for instrument clusters that you might have lying around, be sure to check out this cluster used for video games.

The mechanics in dashboards are awesome, and produced at scale. That’s why our own [Adam Fabio] is able to get a hold of that type of hardware for his Analog Gauge Stepper kit. He simply adds a 3D printed needle, and a PCB to make interfacing easy.

Continue reading “Instrument Cluster Clock Gets The Show On The Road” →

Arduinos (and Other AVRs) Write To Own Flash

July 3, 2015 by 52 Comments

In this post on the Arduino.cc forums and this blog post, [Majek] announced that he had fooled the AVR microcontroller inside and Arduino into writing user data into its own flash memory during runtime. Wow!

[Majek] has pulled off a very neat hack here. Normally, an AVR microcontroller can’t write to its own flash memory except when it’s in bootloader mode, and you’re stuck using EEPROM when you want to save non-volatile data. But EEPROM is scarce, relative to flash.

Now, under normal circumstances, writing into the flash program memory can get you into trouble. Indeed, the AVR has protections to prevent code that’s not hosted in the bootloader memory block from writing to flash. But of course, the bootloader has to be able to program the chip, so there’s got to be a way in.

The trick is that [Majek] has carefully modified the Arduino’s Optiboot bootloader so that it exposes a flash-write (SPM) command at a known location, so that he can then use this function from outside the bootloader. The AVR doesn’t prevent the SPM from proceeding, because it’s being called from within the bootloader memory, and all is well.

The modified version of the Optiboot bootloader is available on [Majek]’s Github.  If you want to see how he did it, here are the diffs. A particularly nice touch is that this is all wrapped up in easy-to-write code with a working demo. So next time you’ve filled up the EEPROM, you can reach for this hack and log your data into flash program memory.

Thanks [Koepel] for the tip!

Retro-fit Old Radio With Arduino And FM Module

July 2, 2015 by 30 Comments

“You can’t put new wine in old bottles” – so the saying goes. But you would if you’re a hacker stuck with a radio built in 2005, which looked like it was put together using technology from 1975. [Marcus Jenkins] did just that, pulling out the innards from his old radio and converting it to an Arduino FM radio.

His cheap, mains powered radio was pretty bad at tuning. It had trouble locating stations, and tended to drift. One look at the insides, and it was obvious that it was not well engineered at all, so any attempts at fixing it would be pointless. Instead, he drew up a simple schematic that used an Arduino Nano, an FM radio module based on the TEA5767, and an audio amplifier based on the LM386.

A single button on the Arduino helps cycle through a range of preset frequencies stored in memory. The Arduino connects to the FM radio module over I2C. The existing antenna was connected to the TEA5767 module. The radio module outputs stereo audio, but [Marcus] was content with using just a mono channel, as it would be used in his workshop. The audio amplifier is pretty straightforward, based on a typical application found in the data sheet. He put it all together on proto-board, although soldering the FM radio module was a bit tricky. The Arduino code is quite simple, and available for download (zip file).

He retained the original tuning knob, which is no longer functional. The AM-FM selector knob was fitted with a micro-switch connected to the Arduino for selecting the preset stations. Almost everything inside was held together with what [Marcus] calls “hot-snot” glue. The whole exercise cost him a few Euros, and parts scavenged from his parts bin. A good radio could probably be had for a few Euros from a yard sale and much less effort, but that wouldn’t be as cool as this.

Go deeper and explore how FM signals are modulated and demodulated for playback.

Disassembled Mouse Keeps Track Of Gas Meter

June 30, 2015 by 33 Comments

After building devices that can read his home’s electricity usage, [Dave] set out to build something that could measure the other energy source to his house: his gas line. Rather than tapping into the line and measuring the gas directly, his (much safer) method was to simply monitor the gas meter itself.

The major hurdle that [Dave] had to jump was dealing with an ancient meter with absolutely no modern electronics like some other meters have that make this job a little easier. The meter has “1985” stamped on it which might be the manufacturing date, but for this meter even assuming that it’s that new might be too generous. In any event, the only option was to build something that could physically watch the spinning dial. To accomplish this, [Dave] used the sensor from an optical mouse.

The sensor is surrounded by LEDs which illuminate the dial. When the dial passes a certain point, the sensor alerts an Arduino that one revolution has occurred. Once the Arduino has this information, the rest is a piece of cake. [Dave] used KiCad to design the PCB and also had access to a laser cutter for the enclosure. It’s a great piece of modern technology that helps integrate old analog technology into the modern world. This wasn’t [Dave]’s first energy monitoring system either; be sure to check out his electricity meter that we featured a few years ago.

Vibrating Distance Torch Illuminates The Dark Without Light

June 30, 2015 by 37 Comments

If you’ve ever had to move around in a dark room before, you know how frustrating it can be. This is especially true if you are in an unfamiliar place. [Brian] has attempted to help solve this problem by building a vibrating distance sensor that is intuitive to use.

The main circuit is rather simple. An Arduino is hooked up to both an ultrasonic distance sensor and a vibrating motor. The distance sensor uses sound to determine the distance of an object by calculating how long it takes for an emitted sound to return to the sensor. The sensor uses sounds that are above the range of human hearing, so no one in the vicinity will hear it. The Arduino then vibrates a motor quickly if the object is very close, or slowly if it is far away. The whole circuit is powered by a 9V battery.

The real trick to this project is that the entire thing is housed inside of an old flashlight. [Brian] used OpenSCAD to design a custom plastic mount. This mount replaces the flashlight lens and allows the ultrasonic sensor to be secured to the front of the flashlight. The flashlight housing makes the device very intuitive to use. You simply point the flashlight in front of you and press the button. Instead of shining a bright light, the flashlight vibrates to let you know if the way ahead is clear. This way the user can more easily navigate around in the dark without the risk of being seen or waking up people in the area.

This reminds us of project Tacit, which used two of these ultrasonic sensors mounted on a fingerless glove.