3DR Solo of my very own!

hacking, Quadcopters

If you’ve followed this blog, you know I’ve played with toy quadcopters and built one from parts. I’ve also built an FPV racing drone that I’ve only successfully flown twice.

For a long time I’ve lusted after a GPS drone capable of autopilot, especially after a demo by a neighborhood friend of his DJI Phantom 3. I think the DJI drones are pretty cool, but I hate that they are not open, and being both an Open Hardware guy, and never satisfied with factory settings, I really wanted open source.

3D Robotics, founded by former Wired editor Chris Anderson has been making open source autopilot drones for quite a while now, but they’ve been quite pricey, and don’t include a camera. I just couldn’t justify it.

My friend Michael Castor at  http://www.mcmelectronics.com/ clued me in to a sale at Bestbuy and I scooped up a Solo, extra battery, gimbal, extra propellers, and a backpack for $399 (plus tax). SCORE!

Note, last time I checked, the price just went up to $599, but you can still get the Solo for $399

Free 2 day shipping said it would be here Thursday, but the Solo came on Wednesday, and the rest on Thursday.

solo box

It was well packed, comes with battery, two extra propellers, transmitter,  and chargers for the transmitter and the battery. It comes with an eggcrate material carrying case that would probably do for a while, but I hate to think what would happen when it rains.

The backpack, which came later (and I may cover in a future post) is terrific."carrying case"

DJI, by the way also gives you “carrying case” packing, but in their case close cell foam, which would probably hold up longer.

Solo unboxing

Setting it up was pretty easy, download the app to my phone, power everything up. There’s a required firmware update before flying, and while it crashed my phone a couple times (I am suspicious because I have CyanogenMod) it took only about 2 minutes.

I don’t have a camera yet (I’m waiting for a new model of “fauxpro” from mcm electronics.) but It was amazing that I actually managed to work all week without flying. A quick stop at the FAA site to register, print a label for my Solo, then I did get out on Saturday, and I’m hooked!

Kevin flying his new Solo
Photo by Will Caldico0tt

Auto take off and landing are the bomb! The orbit mode was pretty easy to use, once I figured out how to set the center on my tiny phone screen. I ordered an acer tablet from ebay (about $70) and hope that will be better.

3DR recommends initial flights in a wide open area, and I concur. While it’s really easy to fly, it’s also hard to judge depth at distance when it’s flying near trees etc. The next day, I did manage to crash it, breaking 2 propellers, and chipping a third. The Solo was fine though, and shut itself down with the remote talking to me “Crash detected”.

Hacking potential

I wouldn’t have even spent $400 (and will likely spend even more) if it wasn’t easy to add my own hardware and software mods. 3DR makes this really easy, with a well thought out Dev kit python API, and well documented hardware expansion. Check it all out at: https://dev.3dr.com/index.html

What makes this really exciting, is the Solo (in spite of the name) actually has Two processors, a pixhawk flight controller, and a linux based computer. You can actually ssh to the drone, and store scripts for execution during flight.

I’m excited that you can even use OpenCV on the video stream from the camera.

Arduino Robot Class preview

Arduino, electronics, FamilyFun, projects, Robots, workshops

I’m teaching an Arduino Robot class June 29 from 6-8pm at YouDoitElectronics in Needham, Ma. The cost is $99 and you get to take home the robot you build. I’ll show you how to use an Arduino to control DC motors, and read sensors to react to the environment. The robot we’re building will have a sonar sensor for distance, and two line detectors for following a line.
To register email your name phone number and number of participants to events@youdoitelectronics.com. Please include Arduino Robot Workshop in the subject line. You will receive a call back within 1-2 business days. Fee is required at time of registration prior to the start of the workshop. Once registration and payment are complete a reservation confirmation number will secure your spot.

DIY Rayguns!

electronics, FamilyFun, toys

IMG_20160117_244535475

I’ve been going to Arisia (one of Boston’s Science Fiction Conventions) for several years. I always have a great time, and it always amazes me the amount of volunteer effort that goes in to providing amazing programming for everyone. This year I wanted to give something back so I came up with the idea of people building rayguns.

(NOTE: My extra kits are available in my etsy shop: https://www.etsy.com/listing/265475569/diy-raygun-kit)

Regular LED strip is super cheap when you order it from China. It normally runs off 12V, but a 9V battery lights it up just fine. I created a simple laser cut frame to put some LED strips, and then some cool laser cut acrylic disks to give it that groovy 50’s raygun look.

I bought most of the parts myself, but special thanks goes to my friend Jeremy Green at Charles River Maker for donating Laser time for cutting the kits. He’s your goto guy for design, prototyping and digital to physical services with laser cutting and lots of 3D printers!

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A switch makes the trigger, and there’s a fin with holes to add decorations.

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First cut a strip of LEDs. Mine consisted of groupe of 3 led sections.. Cut a strip of 5 sections, two sections on each side and one straddling the middle:

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next glue on the handle “dimensional” bits. These are mainly to make a recess for the battery, and maybe wrap the handle. Super glue works pretty quick, but you could probably use wood glue or whatever is appropriate for your frame:

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Glue the trigger button on, (kindof low, as the disks are pretty close. Actually I moved it down abit after I put the disks on (later step)

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Line up the battery clip and shorten the leads to connect one end (I chose the red, positive wire) to the positive contact on the LED strip. A small wire went from the negative contact to the switch and the other lead of the switch to the negative lead of the battery clip.

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Test, viola!

Next line up the disks where they fit. back them off and put a drop of superglue where each disks goes in order.

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The source files for laser cutting are at: https://github.com/osbock/Baldwisdom/tree/master/DIYRayguns

And now a few pics from the workshop at Arisia!

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Parametric Littlebits Mounting system

3Dprinting, FamilyFun, kit reviews

TL;DR version: I got to borrow the littlebits synth kit, and created a parametric version of the mounting board. The source files are available on github: https://github.com/osbock/Baldwisdom/tree/master/LittleBitsMounts

The Newton Free Library applied for and got a cool LSTA ( Federal Library Services and Technology Act) Grant to do a bunch of STEM related programs, and I have the honor of doing a bunch of coding and robotics workshops there over the next few months.

They got a bunch of cool new equipment to run these programs including Finch Robots, Arduinos (Sparkfun Inventors Kits), a KIBO robot, and … wait for it… a bunch of Littlebits sets. NFL Assitant Director Jill Grabowski was kind enough to lend me the coolest littlebits set: The Korg Synth kit.

korgset

 

If you aren’t familiar, they are modular electronics blocks that snap together with magnets. Unlike earlier “electronics construction sets” these are pretty foolproof, well thought out modules instead of just individual components. As Founder Ayah Bdeir says ,

AT LITTLEBITS, WE ARE ON A MISSION TO DEMOCRATIZE HARDWARE BY EMPOWERING EVERYONE TO CREATE INVENTIONS, LARGE AND SMALL, WITH OUR PLATFORM OF EASY-TO-USE ELECTRONIC BUILDING BLOCKS.

Unfortunately the thing that makes Littlebits easy is also it’s greatest weakness: The magnetic connection system.

Especially when making something you have to manipulate (like a musical instrument), they tend to come apart, you lose power, etc.

Now some of the other (more expensive) sets come with mounting plates (that you can also buy separately. I didn’t have one though, but I do have a laser cutter and a 3D printer. How hard could it be? Well, the devil is in the details.

First I looked to see if it was already done. Thingiverse (I know boo….) has a few designs, including some by littlebits themselves, mostly specific component mounts.

Rex Brodie posted this cool clip that fastens adjacent modules together.
clips

It works pretty well (very solid) but it was difficult to put the two bits in without pulling and pushing and putting a bit of strain on the boards. (Especially scary when the ‘bits are on loan).

I tried just measuring and cutting holes with my laser, or a simple model with Open SCAD but I just couldn’t get the spacing quite right.

Thingiverse user Kris Kitchen had posted this design:
littlebitsgrid

which I printed and actually worked quite well. Only problem was, it was an STL (Surface Tessellation Layer) file, and thus not easily modifiable. I wanted wider, arbitrary shapes, etc!

I could however pull Kris’s design into OpenSCAD, and do a trick to measure the “holes” and spacing.

This little bit of code:
[code]
projection(cut=false)difference(){
translate([0,0,-41])import(“LittlbitsGridthin.stl”);
translate([0,0,-10])cube([250,40,10]);
}
[/code]
cuts off the bottom so the holes will show and projects the outline in 2D.

projection

I then exported this as a DXF file, and used inkscape to make measurements.

If I haven’t lost you by now, the part you are waiting for, the measurements (which I couldn’t find anywhere after much googling!)

  • Holes: 6 mm diameter
  • Spacing (edge to edge or center to center): 6.63mm
  • spacing is also 10.5% of hole
  • 1.294mm knockout line

The percentage bit is important (I calculated it, 6.63/6) if you are designing in inkscape because that is how you do a grid of evenly spaced objects.

I made a couple of attempts at a laser cut version, but it was very brittle, and I didn’t take into account the laser’s kerf (width of cut)

The 3D printed version came out pretty well, but the holes were a bit too small, so I enlarged them by .2mm (.1mm on the radius). and it worked perfectly!
littlebitsmounted

Now we can make mounting boards in any shape!
star

The source files are available on github: https://github.com/osbock/Baldwisdom/tree/master/LittleBitsMounts

Is 3D printing good for anything practical?

3Dprinting

When I took my Mini Cooper in for it’s annual state safety and emissions inspection it failed because one of the tail lights was out, and the license plate lights were, well really out. One of the lenses had long ago fell out, and the other bulb was dead.

20151119_175622When I looked on line, the cost for a couple of lenses and the bulbs was greater than a complete unit with LEDs (never replace again!) so I ordered a pair from ebay. They came, but the contacts wouldn’t make connection with the bulb holders.

I communicated with the Ebay seller, and they were great, offering me a refund or to find the right bulbs for me, but I was impatient.

I decided to make a bulb proxy and solder wires between it and the new LED fixtures. It only took 10 minutes to whip something up in OpenSCAD:

scadimage

It didn’t have to be pretty it just had to fit and hold the contacts in place. For contacts I wrapped the ends in copper tape, and soldered wires between those and the light fixtures.

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Note, that it’s easier to solder to any delicate surface if you use liquid flux.

The result was fantastic (pay no attention to the filth on my car….)

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Hopefully it will pass inspection tomorrow. Of course if I didn’t have all this stuff at home, it totally wouldn’t have made sense to do this, but I do, and it was actually a fairly fun and easy project.

 

Arduino Workshop and Arduino Resources page

Arduino, workshops

youdoit-arduino class

Had a full house at an Intro to Arduino Workshop at YouDoIt Electronics in Needham last night. Getting ready for this prompted me to start up an Arduino Resources page and update my Intro to Arduino Presentation (which, unfortunately I didn’t get to use due to technical difficulties…)

YouDoIt Electronics is a terrific local resource, carrying tons of Sparkfun and Adafruit products (as well as tons of mechanical and electrical parts, educational toys, AV equipment, you name it!) Thanks Melissa and John for sponsoring me!

Interactive Wall at the Duxbury Free Library

3Dprinting, Arduino, hacking, libraries, projects, workshops

I was Maker in Residence at the Duxbury Free Library in August, where I worked with Teens and some adults to create an Interactive wall for display at the Library.

I met Teen Librarian Ellen Snoeyenobs at the first Make a Makerspace conference at the Artisan’s asylum several years ago, and we’ve been collaborating on bringing more maker activities to her library over the last 2 years. She has an excellent blog reflecting on their successes, failures, and tips : http://librarymakerspace.blogspot.com/

She has her own excellent video here:

Lessons learned

  • Something for everyone. There are art activities for those who won’t go near tech stuff, and plenty of wiring and coding for the techies. Girls, boys, adults alike found something to do.
  • Drawing on skills learned in the past helps to get things done. We did one session on Arduino at the beginning, but in the end, those who already had Arduino experience ending up contributing most in that area.
  • Include a variety of activities. Kids who liked 3D printing and design did various bits to glue on, and use, including a spider that goes up and down. The 3Doodler was used a lot to add decorative elements, as well as enhance some of the 3D prints. And of course, Arduino brought it all to life.
  • Think Off the Wall. Ellen was originally inspired by an interactive wall she saw at MIT. The library, however, wasn’t too keen to be hacking into their existing walls. Ellen came up with the idea of a portable partition, and I helped select one (made of poly-carbonate) that we could drill. It had the additional advantage of being semi transparent, so we could mount our fireflies (addressable LEDs,) behind the wall.
  • Surprise learning. There were all sorts of bonus learnings, including how to scale a drawing up using a grid!

Technology

  • The library had previously received a grant that enabled them to buy a bunch of Spark Fun Inventors kits. We used velcro to attach the Redboards and their attached breadboards to the back of the wall.
  • We used a PIR motion sensor to trigger the bird moving, and cheap Chinese HC-SR04 ultrasound distance sensor to light up the peacock’s tail as you waked closer.
  • WS-2812 LED strips provided bling for both the peacock’s tail and the fireflies.
  • Birdsong was provided by a Sparkfun MP3 Shield
  • Movement was done with micro servos, and one continuous rotation servo from parallax.
  • The shifty eyed fox was implemented by a great design from Dampboot on Thingiverse

Come see it!

Our Grand Reveal of the Arduino Interactive Garden Wall will take place on
Thursday, September 10th at 4 p.m. on the Upper Level of the Duxbury Free Library.

We’re hoping some of the Teens as well as adults who had a hand in making it will talk about the experience.

MacGuyver Copter Part 3: Success!

FamilyFun, projects, Quadcopters

If you have been following along, in Part 1 and Part 2, I was trying to build a simple, cheap and easy quadcopter from spare parts. Well, the simplest methods failed, time to get out the laser!. Acrylic isn’t the best material for a quadcopter frame. It’s relatively heavy, and fairly brittle. but it’s  easy to cut in a laser cutter, which I happen to have, courtesy of Wyolum.com.

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Did it work? Well, it didn’t flip over, but started spinning a bit in place.  When I picked it up with the props going, some of the air was blowing up! I somehow got the ordering and placement of the motors wrong. I cracked open my original X5C (wow, that’s a lot of screws!)

I fixed the wiring, and then it flew! About 6 inches off the ground! I noticed that the props were rotating about 1/4 of a rotation over the body which means a lot of backwash, but the main problem is revealed when I weighed it.

The original Syma x5C with camera and battery weighsin at 97 g.

Version L1 of the MacGuyver Copter: 122g. Flew about 6 inches above the ground.

I created a new version with more or less rounded rectangle arms, and a circular central platform. I was worried because acrylic is rather brittle, and I wanted it to be strong.

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Version L2 of the MacGuyver copter weighed in at  106g. Flew relatively well, but inertia was killer on flips(lots of altitude loss), and battery runs down very quickly. After about 5 minutes, it was again hovering at 6 inches.

Although we think of plastic as light, acrylic is fairly heavy so I tried some plywood. All I had on hand was some 1/4 inch cheapo birch plywood from home depot.

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I forgot to record the wieght of this one (I think it was between 100 and 110 grams), but it worked quite well. The only problems were that my cutouts came a little close to the edge, and between the cheap plywood (voids) and those thin areas, one of the arms broke in a crash.

The final design simplified the cutout to be a triangle and weighs in at 84g, compared to the x5, without the camera or battery door at 88G. There are probably lighter, equally stiff materials, but this is pretty easy to do.

1-MacGuyverV3

Flys fantastic, at least to my feel It seems better than the stock version without the camera. Even though it’s less “aerodynamic, I think it handles better in a light breeze than the original, probably due to less surface area.

Here’s a (pretty bad) video of it’s flight. Trust me, it’s fun!

I also cut a frame out of 1/8 inch acrylic, but it was way too bendy, and wouldn’t take off. I think the props tended to thrust up, and bend it toward the middle, and the IMU (Inertial Management unit) couldn’t figure out a way to get enough power out to get it in the air.