[Ben Yeh] wrote in to tell us about this voice-controlled chess robot he built along with three others as a final project for their Georgia Tech ECE 4180 Embedded Systems Design class.
To handle the speech recognition they grabbed an EasyVR board. This is a fine solution because it prevents the need for a computer to process voice commands (remember, it’s an embedded systems class). This concept breaks down when you find out that the desktop computer next to the robot is where the chess game is running. Perhaps that can be moved to a microcontroller by the next set of 4180 students.
The robot arm portion of the project is shown off well in the clip after the break. Normally we’d expect to see stepper motors driving the axes of a CNC machine but in this case they’re using servo motors with built-in encoders. The encoders are i2c devices which feed info back to the main controller. There was a parts ordering snafu and the z axis motor doesn’t have an encoder. No problem, they just added a distance sensor and a reflector to measure the up and down movement of the claw.
Filed under: cnc hacks, robots hacks
I always thought it would be cool to build a giant fire breathing piranha plant. I never really came up with an excuse to do it though. Eventually, I just decided I didn’t really need an excuse, and thus it was born.
The plant itself is pretty much just foam and cardboard. You can see the construction process in the video, it was really easy, but a little time consuming. I wanted to go with a bit of a crazy, hyper stylized look, so it is covered in veins and has these insane looking wrinkly lips. The plant itself would be a fun thing just to have around the house. Actually, I may turn it into a lamp.
The fire systems were very much trial and error.
My initial plan was to use a “fire poofer” design with propane like what you would typically see at burningman. I had all the parts ready and was about to build it when the redbull creation challenge started. I ended up using most of the parts to build the redbull cannon.
Before going any further, let me point out that this is not the proper way to make a fire piece. None of these methods are particularly safe.
My plan then changed to be able to use this indoors. I wanted a flame, but not a massive column of fire. To do this I used small bottles of butane in a cobbled together dispenser.
There is a large piece of PVC, with a servo and plunger mounted in the bottom. The cap has a small hole in the top of it, with a long brass tube extending out. The butane bottle is guided into the hole with an old plastic cup, then the whole thing is screwed into place. You can see a small rubber band keeps the butane bottle pushed into the hole, so it doesn’t drop out and just fill the chamber with butane.
When I pressed a button, the servo would push the bottle upwards, releasing butane into the brass tube. Extremely simple, extremely effective. I really liked the fireballs this produced.
When I showed it to people outside though, the first response was that they were expecting a little more fire. The size of the plant itself made the little fireballs a bit underwhelming. So, I built basically the same system to fit a can of carburetor cleaner. Again, horrible idea, completely unsafe.
The carb cleaner did not dispense cleanly, no matter how I tried to adjust the mechanism. Highly flammable liquid sprayed EVERYWHERE including down the sides of the bottle. Luckily I tested this outside of the plant. It was a complete failure and I got a chance to use that fire extinguisher.
I ended up putting the piranha plant away for the winter, but once the sun came out, I wanted to get it out again. I considered tearing apart the redbull cannon for the parts and going back to the propane poofer, but ultimately decided I’d save that for another fire project.
The final outdoor fire system I used took a total of about 15 minutes to make. It is a cylinder, with a hose attached to it. You put creamer (fine powder, not liquid, obviously) inside it. A blast of compressed air shoots it upwards, through the flame of your choice, causing a rolling fireball. There’s a knot in the hose to stop the creamer from pouring all the way down. I’m sure there were a million other ways to do it, but this worked.
While the construction was easy, the implementation wasn’t so straightforward. I found that in many cases, less is more. Too much air pressure simply sprayed creamer everywhere with no fire. Too much creamer would ignite, but then fall while still on fire to the ground, or the plant. A quick puff of roughly 30lbs pressure and about a quarter to half cup of creamer gave me some nice fire balls that easily went 10 feet upwards.
Ultimately, I think I’d probably just put in the propane powered fire poofer if I were to use this for an event. The creamer worked ok for the video but was a mess and took a lot of set up in between shots.
Oh yeah, be sure to catch the shot at the end of the video where the gopro fell off the quadcopter. You can see the quadcopter still flying in the air above me when I retrieve the camera.
Filed under: Featured, nintendo hacks
Check out the Einstein head which [Sebastian Müller] etched on the cover of his calculator using a laser engraver he made from scratch. We think he did a great job with the build, but we’re even more impressed with the work he put into sharing the techniques he used to salvage and repurpose all the components. It’s a perfect resource that should be pretty easy to adapt to different model/manufacturer source hardware.
He used an old scanner and an old printer for the bulk of the parts. These both originally included stepper-motor actuated gantries, which pull together to form the x and y axes in his Frankenstein Laser Engraver. As the parts came together he started in on the control electronics which include a couple of EasyDriver stepper motor boards and an Arduino.
At this point he took the machine for a test-run, attaching a marker to the carriage to use it as a pen plotter. After putting in a solid performance at this [Sebastian] moved on to adding in the laser diode. He covers how to drive the diode, as well as focal point alignment in great detail. It seems like his webpage post has the same content as the Instructable linked above but we wanted to leave the link just in case.
Filed under: laser hacks
Behold, something we’ve always wanted. [Matthieu] mounted his Raspberry Pi board inside of a computer monitor. His work makes for the cheapest smart-TV modification we can possibly think of.
The image above shows the monitor’s driver board on the left, with the Raspberry Pi mounted on the back plastic cover. [Matthieu] used a short HDMI cable to connect the two. The HDMI connector plugs into the RPi directly. The other end has been cut off and the wires soldered to the DVI pins on the monitor’s PCB. This is not a problem since HDMI and DVI use electrically identical protocols. The one thing missing is audio. But if you were pulling off the same hack with a device that had HDMI (like a television) it would just be a matter of also soldering in the audio connections. While he had his iron hot he also connected a 5V source from the monitor board to the RPi. He completes his hack by cutting a slot in the monitor case to allow access to the SD card.
We’ve long wanted an XBMC computer we could velcro to the back of the TV and the RPi turned out to be just the thing. Now we’ve got to consider cracking open the TV to replicate this internalization hack!
Filed under: home entertainment hacks
The blue board seen above is the guts of a product called the eeColor Color3. It was designed to act as a pass-through between your television and HDMI source device. It boasts the ability to adjust the color saturation to suit any viewing conditions. But [Taylor Killian] could care less about what the thing was made for, he tore it open and used the FPGA inside for his own purposes.
The obvious problem with this compared to a proper dev board is that the pins are not all broken out in a user-friendly way. But he got his hands on it for free after a mail-in-rebate (you might find one online for less than $10 if you’re lucky) and it’s got an Altera Cyclone IV chip with 30k (EP4CE30F23C6N) gates in it so he’s not complaining. The first project he took on with his new toy was to load up an open source Bitcoin mining program. The image above shows it grinding away at 15 megahashes per second while consuming only 2.5 watts. Not bad. Now he just needs to make a modular rack to hold a mining farm.
Filed under: FPGA