Reactive Drums - The Final Product

These are the drums as they appeared tonight at the Indianapolis Museum of Art Winter Solstice Celebration.  The weather was full on suck, but the drums still consistently drew a crowd.  Four of us from Dorkbot Indy made the project happen, +Tom Streit and +Jordan Munson did the heavy lifting getting the drum shells made, heads mounted, and everything looking cool. +Brandon Ferguson wrote all the code, and I put the electronics together.

Short Test Video of Reactive Drum Project

This is a short test of the reactive drums project I've been working on the past month with three other guys from Dorkbot Indy.  Tom and Jordan built the drums, Brandon wrote the code, and I designed and built all the electronics.  We made four drums from 12 inches in diameter to 24 inches and they were all delivered to the Indianapolis Museum of Art this week.

Drum Electronics

This is a start on electronics for my drum.  I use an Arduino clone, an Adafruit PWM board, and a piezoelectric sensor to implement the lights.  The software is really straight forward right now, just implementing what is in effect a VU meter.

If you look carefully at the video, you can see a difference in the circuit's reaction between the beginning and the end of the video.  Right now I've just got the piezo stuck to the drum head with electrical tape.  After playing for a while, the sensor looses some of it's connection to the head, and the sensitivity goes down.

First Hand Made Drum

This is video of me playing my first hand made drum - put together out of scrap laying around the shop.  The drum sounds good, I just suck as a drummer.

Compressed Air Rocket Launcher

For my son's birthday I built this launcher using plans from Make:Projects.  One shot from our driveway went about 150 feet up.  I was pretty surprised.  Tomorrow we take it to the park to see what she's really got.

Updated Linear Actuator

This is the latest refinement of my linear actuator project.  I had some reliability issues with the old design, so I added deep groove ball bearings to the shaft.  It's now ready for prime time, and was installed in the robot last weekend.

Mock-up of robot arm

I spent about two hours putting together this mock-up of an arm for a boxing robot.  I built it to figure out the geometry required to get the motion I was after, while keeping with one degree of freedom.  It's built with a standard hobby servo and my arduino running the servo library.  the forearm is 6.5 inches, and it's on scale for a 45 inch tall robot.

2012 Indiana Robotics Invitational

Today I attended some of the 2012 Indiana Robotics Invitational.  It's a First  competition for students in grades 9-12.  Teams of about 40 students have 6 weeks to build a robot.  Then at competition two alliances of three teams each go up against each other in a points match.  As you can see in the picture this year's game is a version of basket ball where robots need to collect balls off the floor and shoot baskets.  At the beginning of each match the robots operate autonomously for 15 seconds, then are tele-operated for the rest of the match.  There were 70 some teams invited to compete this year, so it was very crowded and very busy, and uber cool.

Cheap Linear Actuator

The actuator in the video was built for about $13.00.  This price includes the H-bridge, motor, and all the mechanicals.  I've got eight of these to build for the Dorkbot Indy project I'm working on.

Newest Member of the Robot Collection

This little guy is about 45 mm square, and about 55 tall.  The software is still under development, but he scoots around - sort of avoiding light  - at this point.  The 8-pin chip is an ATTiny85.  I write code with the Arduino IDE and program it using my Arduino as an ISP.  After getting B.bro 1.0 to act like a Braitenberg vehicle I decided to see how cheap and small I could go.  With different motors I think I can get the size down to about 25 x 30 mm with a unit cost of about $4.00 in quantities of 50.  I want to build 50.

Braitenberg Vehicle Comes to Life

"Vehicles" by Valentino Braitenberg is one of my favorite books.  This version of the B.bro's software causes him to behave as a type 4a vehicle.  I was very surprised how stable the behavior is, and how well it adapts to changes.

B.bro 1.1 - light seeking upgrade

I got a little sick of working on my string based drawbot, so I decided to go back to the bot that started it all for me.  This is B.bro - named for the White Stripes song "Baby Brother".  In the last two days I've added analog light sensors to him, and written light seeking software to work with them.  I'm pretty pleased.  There's video of him running on YouTube.

All DrawBot Source and Design Files Available

I've finally created a github account, and uploaded all the source code and Eagle design files for the DrawBot. There's no documentation to go along with it yet, but that's coming.

Last bugs worked out

I've posted a couple of pictures for comparison. The first is an SVG file as rendered by Inkscape. The second one is a photo of the same SVG as drawn by my drawbot.

Pen Carrier Upgrade Goes Live

Here's a still of my pen carrier with the up/down mechanism installed, wired, and working, and here's a video sample of the bot doing its very first drawing with the new hardware. I'm sorry for the watermark on the video. I need to find a good free video editor.

The actual drawing is an .svg file done in Inkscape. It's a path tracing of a bit map image I found on Google images. If you'd like to have the bot do a drawing for you, send me an .svg (everything must be a path) and I'll send you back a drawing.

Further work on the Drawbot

Recent work on the drawbot has been following three parallel lines:

• First I'm working on a little servo driver board to control a pen up/down mechanism. I've got the electronics and code working, now I'm building the actual mechanism. In the first version I'll run power and comm through wires up to the pen carrier. I just got some wireless transceivers from Sparkfun, so eventually the pen carrier will hold batteries, electronics, and the mechanism, and control will be wireless. That way I won't have to cope with the mass and drag of wires.
• Second, I've rewritten my command protocol to less primitive and more robust. The boxes and pen up/down electronics all have the same address when initially programmed. Now I've got a command protocol where I can readdress the hardware and it will keep the new address in flash memory when powered down. Right now it's not such a big deal, but in the future this will allow me to very quickly reconfigure the drawbot (i.e. adding axis, other carrier controls, etc.) on the fly.
• Third, and probably the most fun, I've been creating a bunch of drawings in Inkscape for the bot to draw - and at the same time debugging my .svg reader. The bot will draw simple .svg files now, and I'm working slowly through the details of Inkscape's implementation of .svg and learning the math to draw cubic spline curves with the bot. The image above is one example of the Inkscape work I've been doing. It's a drawing by daVinci - vectorized and cleaned up a bit.

New Drawbot Attends Gallery Opening

I haven't been blogging about the development of my newest drawbot, mostly because I've been under such pressure to get it done. I made the deadline last Friday, and the 'bot drew pictures for several hours during the premier event of the daVinci Pursuit. I've also posted some pictures on flickr and video on youtube. Now that the hardware is pretty well worked out, I'm working on improving the software. I'll post more as things progress.