THP Hacker Bio: hackersbench

 

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Remote sensing applications that make sense and cents? (sorry, couldn’t help ourselves) That’s what [hackersbench], aka [John Schuch], aka [@JohnS_AZ] is working on as his entry for The Hackaday Prize.

He received a multi-thousand-dollar water bill after having an underground pipe break and leak without knowing it. His idea will help you notice problems like this sooner. But if you actually have a way to capture data about your own water use you also have a tool to help encourage less wasteful water use habits. We wanted to learn more about the hacker who is working on this project. [John's] answers to our slate of questions are after the break.

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Developed on Hackaday: Discovering Shenzhen and its Companies

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Two weeks ago we showed a first demonstration video of the offline password keeper (aka Mooltipass) the Hackaday community had been working on for the last 6 months. We received lots of interesting feedback from our dear readers and around a thousand of them let us know they were interested in purchasing the device. We agreed that preferential pricing should be offered to them, as they have been supporting this community driven project for so long.

For the next few days I will be touring Shenzhen and finally meeting the persons who have been assembling my electronics projects for the last 2 years, including the Mooltipass beta testers’ batch. I’ll also meet with Ian from Dangerous Prototypes, talk with the people behind the Haxlr8r program, visit Seeedstudio offices and a CNC shop. If everything goes well with the camera I just purchased in Hong Kong I should have nice things to show you. In the meantime, don’t hesitate to leave a comment below in case you’re in the area…

Retrotechtacular: AT&T’s Hello Machine

1ESSHow many Ma Bell employees does it take to build an ESS mainframe? This week, Retrotechtacular takes you into the more poetic recesses of the AT&T Archive to answer that very question. This wordless 1974 gem is an 11-minute exploration of the construction and testing of a Western Electric 1ESS. It begins with circuit board population and ends with lots of testing.

 

 

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The film is really quite groovy, especially the extreme closeups of wire wrapping and relay construction. The soundtrack is a string-heavy suite that moves you through the phases of bringing up the 1ESS while drawing parallels to the wires of communication. You may lose count of the punch down blocks and miles of cables, but there are surprisingly few mustaches.

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Hackaday Links: July 13, 2014

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Don’t like sunglasses? Deal with it. They’re the pixeley, retro sunglasses from your favorite animated .GIFs, made real in laser cut acrylic. Points of interest include heat-bent frames made out of a single piece of acrylic.

Remember this really small FPGA board? The kickstarter is ending really soon and they’re upgrading it (for an additional $30) with a much better FPGA.

Sparkfun is now hosting the Internet of Things. They’re giving people a tiny bit of space to push data to, and you can also deploy your own server. That’s interesting, and you can expect us doing a full post on this soon.

Need waveforms? [Datanoise] is building a wavetable synthesizer, and he’s put all his waveforms online. Now if we could just get a look at the synth…

If you only have $20 to spend on a board, you’ll want to pick up at Teensy 3.1. [Karl] wrote some bare metal libraries for this awesome board, and while it’s not as extensive as the standard Arduino libs, it’s more than enough to get most projects off the ground. Included are UARTs, string manipulation tools, support for the periodic interval timers on the chip, and FAT and SD card support.

The Hacklet #7 – MIDI

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This week’s Hacklet is all about Hackaday.io projects which use MIDI, or Musical Instrument Digital Interface for the uninitiated. MIDI was designed from the ground up as an open communications standard for musical instruments. Nearly every major instrument company participated in the design of the standard. MIDI was first demonstrated in January of 1983, with the communications standard document following in August. Hackers, makers, and musicians immediately ran with it, using MIDI to do things the designers never dreamed of.

SAMSUNG[Robert's] 9×9 Pixel Muon Detector/Hodoscope  is a great example of this. [Robert] is using 18 Geiger Muller Tubes to detect cosmic particles, specifically muons. The tubes are stacked in two rows which allows him to use coincidence detection. Rather than just plot some graphs or calculate impact probabilities, [Robert] hacked a Korg Nanokey 2 MIDI controller to output MIDI over USB messages corresponding to the detected muons. Check out his video to see a sample of the music of the universe!

 

diyMPCNext up is [Michele's] DIY MPC style MIDI controller. [Michele] needed a simple low-cost drum controller that wouldn’t wake his neighbors. He loved Akai MPC controllers, so he rolled his own. [Michele] investigated force sensitive resistors but found they were very expensive. At a cost of $8 USD each, his resistors alone would be nearly the cost of a low-end MPC!  [Michele] created his own sensitive pads using a sandwich of copper tape and 3M Velostat conductive sheets. An HCF4067 routes all the analog lines to a single pin of Teensy 3.0, which then converts the analog resistor outputs to MIDI messages.

pic-midi-1vo[Johan] loves his analog synths, and wanted them to be able to talk MIDI too. He built MIDI2VC, a circuit which converts MIDI to 1V/Octave (similar to  CV/Gate). 1V/Octave is an analog control system used in some early synthesizers, as well as many modern analog creations. Pitches are assigned voltages, and as the name implies, each octave is 1 volt. A4 on the keyboard is represented by 4 volts, while A5 is 5 volts. [Johan] used a Microchip PIC16LF1823 to receive and convert the MIDI signals. The PIC outputs I2C data to an MCP4725 DAC which drives the analog side of the house.

eldanceLong before DMX512 came on the scene, hackers were controlling lights via MIDI. [Artis] continues this with El Dance, a wireless system for controlling electroluminescent wire worn by dancers. Similar in function to  [Akiba's] EL wire system, [Artis] took a lower cost route and used the venerable NRF24L01 radio module. He added an antenna which gives the modules a range of about 30 meters. The computer running the dance routine’s music sees the transmitter side of the link as a MIDI instrument. Standard note on and off commands activate the EL wire strings.

midi-vibeOur final hack comes from [Jen] who built a MIDI Vibrator Inductor Synth. [Jen] performs in an experimental music band called My Wife, with instruments as varied as violins and sewing machines. [Jen] must be a fan of Van Halen’s Poundcake as she’s using a similar technique, with a MIDI twist. An Arduino converts MIDI notes to analog values, which are sent to a motor controller board. The motor controller uses PWM to drive a vibrator motor at the frequency of the note being played. Like all DC motors, the vibrator puts out a ton of electromagnetic noise, which is easily picked up by [Jen's] electric bass.

That’s it for this week’s Hacklet! Tune in next week for more projects from Hackday.io!

 

THP Hacker Bio: nsted

 

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Have you ever wanted to build a robot arm, or even a full robot, but were put off by the daunting task of making all of those articulations work? Moti could make that a lot easier. The project seeks to produce smart servo motors which can connect and communicate in many different ways. It’s a great idea, so we wanted to know more about the hacker behind the project. After the jump you’ll find [nsted's] answers to our slate of question for this week’s Hacker Bio.

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Droning On: PID Controllers and Bullet Connectors

droning-on-hill Not all drones are multirotors – Posing in our title photo are Maynard Hill and Cyrus Abdollahi. Maynard’s plane, TAM5 aka The Spirit of Butts Farm, is the smallest aircraft to make a transatlantic flight (YouTube link). Retracing the path of Alcock and Brown from Newfoundland to Ireland, the 6 pound (dry weight) model made the trip in just under 39 hours. All this happened in 2003, and was the cap on a lifetime of achievements for Hill. These are the types of pursuits that will be banned in the USA if the FAA restrictions go into effect.

Flight Controllers

Quite a few of you thought the Naze32 was left out of last column’s flight controller roundup. I hear you loud and clear! I’ll add the Naze to the controllers which will be tested on The Hackaday Testbed. The hard part is finding the darn things! I currently have an Acro Naze32 on its way to Droning On HQ.  If I can find a full version, I’ll add that.

PID Controllers Deep Dive

I’ve gotten a few questions on Proportional Integral Derivative (PID) controllers, so it is worth diving in a bit deeper to explain what a PID controller is. PID controllers are often found in process controls managing parameters like temperature, humidity, or product flow rate. The algorithm was initially designed in the late 1800’s as a method of controlling the helm of large naval ships. In fixed wing drones, PID keeps the plane’s wings level and on course. In multicopters, PID loops control heading, but they also provide the stable flight which allows the quadcopter to fly in the first place. A full explanation of PID loops would be beyond the scope of a single article, but let’s try a 10,000 foot explanation.

pidP: This is the “Present” parameter. P Has the most influence on the behavior of the aircraft.  If the wind blows your quadcopter from level flight into a 30 degree right bank, P is the term which will immediately take action to level the quad out. If the P value is too high, The quadcopter will overshoot level flight and start banking the other way. In fact, way too high a P value can cause a quadcopter to shake as it oscillates or “hunts” for level. Too Low a P value? the quadcopter will be very slow to react, and may never quite reach level flight again.

I: This the “Past” parameter. The I term dampens the overshoot and oscillations of the P term, and avoids the tendency of P to settle above or below the set point. Just like with P, too high an I term can lead to oscillation.

D: This is the “Future” parameter, and has the smallest impact on the behavior of the aircraft. In fact, some flight controllers leave it out entirely.  If P and I are approaching a set point too quickly, overshoot is likely to occur. D slows things down before the overshoot happens.

So why do multicopter pilots dread PID tuning?  Quite simply, it’s a tedious process. Couple a new pilot and an unproven aircraft with un-tuned PID values, and you have a recipe for frustration – and broken propellers. Things get even more complex when you consider the fact that there are at least 3 sets of PID variables to be tuned – Pitch, Roll, and Yaw. Some flight controllers now support multiple PID values depending on the style of flight. Want your plane or multicopter to fly around like a hotrod? You need a totally different set of PID values than a docile trainer craft. Rolf Bakke (KapteinKUK himself) made a video illustrating how multicopters behave when tuning PID values. You can easily see how a quad can go from “drunk” to “angry bee” with just a few value tweaks. All this is coming together with The Hackaday Testbed, which will help me in posting a few PID tuning videos of my own.

Hackaday Testbed Update

As for the testbed itself, it’s nearly complete! You can follow the progress on my Hackaday Projects Page. Most of the assembly has been relatively straightforward.   though of course there are always a few snags. It seems I always forget something when ordering up parts for coils-bada build. In this case it was 2.5mm banana plugs and motor mounting screws.

The Hobbyking motors attach to the frame with 3mm screws. The problem is that there really is no way to know how long the screws should be until you have the motors, mounting plates and drone frame on hand. I have a bunch of 3mm screws of various lengths, and thankfully there were enough screws of the correct length to mount the motors. Murphy is always at my side, as I accidentally grabbed a screw that was 1mm too long and, you guessed it, screwed right into the windings of the motor. Doh! Thankfully I had spares.

bullet-solderBullet connectors can be a real pain to solder. There are some jigs out there which help, but I’ve always found myself going back to the old “helping hands” alligator clips. Bullets tend to use lower gauge wire than we’re used to with regular electronics. 14, 12, even 8 gauge wires are used on R/C aircraft. A low power soldering iron with a surface mount tip just won’t cut it. Those irons just doesn’t have the thermal mass to get the connectors up to soldering temperature. This is one of those places where a decent 40 watt or better Weller iron (yes, the kind that plugs right in the wall) can be a godsend. I’m using an Metcal iron here, with a wide flat tip.

bullet-solder-2Bare bullet connectors and alligator clips can also create a problem – the metal clips create even more thermal mass. Years back an old-timer showed me a trick to handle this. Slip a piece of silicone R/C plane fuel tubing on the bullet, and then clip the helping hands onto the tube. The tube will act as insulation between the bullet and the clip. Silicone can easily withstand the temperatures of soldering. I’ve also used the silicone tube on the jaws themselves – though eventually the jaws will cut the soft tubing.

That’s about it for this edition Droning on! Until next time, keep ‘em flying!

Title photo credit Cyrus Abdollahi.