I bought a Dremel and bored out the socket where the handset cord was coming out of. Then I stuck the screen and cell shield in there. Now the rotary cell phone is self contained and pretty.
Sunday, October 19, 2014
Monday, September 22, 2014
The Rotary Cell Phone
I turned an old rotary phone into a cell phone. For some reason I wanted to make the world's most useless cell phone, or the world's first rotary phone. It was fun to build and definitely a conversation piece.
It looks like I threw it together in a day because I did. I also can't solder anything so it will probably stay the way it is.
It looks like I threw it together in a day because I did. I also can't solder anything so it will probably stay the way it is.
This is what I started with: a clamshell rotary phone, probably from a hotel. I have no idea how old it is. You can buy one off of eBay for about ten dollars.
The finished product. I may move those electronics inside the device to make it look less like a bomb.
My workshop
Opening the beast. I disregarded most of the electronics inside.
Testing the rotary mechanism. I pulled off four wires and hooked them up to an LED circuit to see how they would behave as I dialed numbers. As I suspected, one circuit closed when the dial was in motion, and another flipped on and off, counting up to count the number you dialed. It was easy to then hook these wires up to Arduino digital pins and count the numbers in software.
I had a lot of help from these instructions: http://www.instructables.com/id/ArduinoPhone/
This helped me get the handset working: http://www.instructables.com/id/Adapting-a-Telephone-Handset-to-a-Cell-Phone/
I used an Arduino Uno and Seeed Studio GPRS and TFT touch screen shields.
Tuesday, March 18, 2014
From Paper to Plastic
Edit: This project has been featured on 3DPrinterWorld.com! If you're interested in more information, you can contact me at dylanhrush at gmail.
Some time ago I had an idea for a tablet application in which users could draw two dimensional representations of objects, and they would come to life in 3D. At the basic level, users would be interacting with a virtual ball of clay, or slab of marble, and various transformations could be made: users could cut sections away, drill holes, or make indentations. This was to be a personal, experimental project, just to see what I could create. What I made ended up looking like a rudimentary version of Autodesk Meshmixer. At first I started writing this using polygons to represent the virtual matter, but it was way too difficult. The triangulation of polygons for drawing and intersection tests turns out to be a computationally hard problem, and splitting solid polygons across planes was not an easy task. I ended up avoiding polygons altogether; now everything is based on Octrees. I named my app Marble, as using it feels more like marble than clay.
Anyway, I'm not going to divulge much more about Marble in this post. Instead I'd like to share an interesting related project. I realized that tablet input is not the only way that users can draw on the 2D plane. What if you could draw an outline of some object on paper, and have it come to life right before your eyes? I wanted to build a machine where you feed in your sketches on paper, and the device creates those objects for you. That's exactly what I did.
The current process is very hands on. My vision is to automate this process to the point where you put some paper on the scanner bed, press a button and your object is generated before you. I don't believe this has any realistic industrial applications. I just think it's a cool project.
For the maiden voyage I drew a very simple sketch of the Eiffel Tower. The input to this system takes at least three images: a front, side and top view:
The hardware: a Printrbot Simple, a Canoscan 4200F (the cheapest scanner I could find,) and my laptop. Installing drivers for the scanner was arguably the most difficult part of this project.
.JPG)
I made monochrome images of the scan and imported them into the Marble application. (I said this was a tablet app, but it runs on desktops as well.) Marble cuts the slab along the outlines of the drawings, and discards what is not filled in. It does this three times, rotating the slab between cuts. I chose to use just three cuts for simplicity, but the software can cut the slab against any number of angles.
You might notice that the model is a bit jagged. My old laptop could not handle a higher resolution without slowing down significantly.
.JPG)
.JPG)
I imported the Marble model into Blender. As I wrote the app myself, I had to create my own file format for Marble models. I wrote a Blender python script to read this file format and generate a corresponding mesh.
Once the mesh is in Blender, it's simple to generate an STL and get printing!
.JPG)
The final product:
.jpeg)
.jpeg)
Some time ago I had an idea for a tablet application in which users could draw two dimensional representations of objects, and they would come to life in 3D. At the basic level, users would be interacting with a virtual ball of clay, or slab of marble, and various transformations could be made: users could cut sections away, drill holes, or make indentations. This was to be a personal, experimental project, just to see what I could create. What I made ended up looking like a rudimentary version of Autodesk Meshmixer. At first I started writing this using polygons to represent the virtual matter, but it was way too difficult. The triangulation of polygons for drawing and intersection tests turns out to be a computationally hard problem, and splitting solid polygons across planes was not an easy task. I ended up avoiding polygons altogether; now everything is based on Octrees. I named my app Marble, as using it feels more like marble than clay.
Anyway, I'm not going to divulge much more about Marble in this post. Instead I'd like to share an interesting related project. I realized that tablet input is not the only way that users can draw on the 2D plane. What if you could draw an outline of some object on paper, and have it come to life right before your eyes? I wanted to build a machine where you feed in your sketches on paper, and the device creates those objects for you. That's exactly what I did.
The current process is very hands on. My vision is to automate this process to the point where you put some paper on the scanner bed, press a button and your object is generated before you. I don't believe this has any realistic industrial applications. I just think it's a cool project.
For the maiden voyage I drew a very simple sketch of the Eiffel Tower. The input to this system takes at least three images: a front, side and top view:
The hardware: a Printrbot Simple, a Canoscan 4200F (the cheapest scanner I could find,) and my laptop. Installing drivers for the scanner was arguably the most difficult part of this project.
I made monochrome images of the scan and imported them into the Marble application. (I said this was a tablet app, but it runs on desktops as well.) Marble cuts the slab along the outlines of the drawings, and discards what is not filled in. It does this three times, rotating the slab between cuts. I chose to use just three cuts for simplicity, but the software can cut the slab against any number of angles.
You might notice that the model is a bit jagged. My old laptop could not handle a higher resolution without slowing down significantly.
Once the mesh is in Blender, it's simple to generate an STL and get printing!
Saturday, December 21, 2013
Visualizing a Fractal with a 3D Printer
I purchased a Printrbot Simple a few weeks ago with the hope to make something cool and unique with it. I did use it to print some Christmas ornaments for my family, which was a good way to break it in. I really wanted to model something myself and have it just appear in real life. The 3D printer is a nifty bridge between art and engineering.
Specifically, I want to do two things with the device: create something no one has seen before, and experiment with different textures as a medium or a means to augment the qualities of an artistic piece. I think it would be interesting to see someone take a two dimensional piece and apply texture to it, so that the piece takes on different qualities when seen from different angles. That's sort of what I'm doing here, but something I'd like to explore further some day.
One thing that I've wanted to do for awhile is visualize the Mandelbrot fractal in three dimensions. If you are not familiar with the Mandelbrot fractal, you can read about it here. To summarize, it's a set of numbers on the complex plain such that when you continuously square and cube the numbers, it does not diverge into infinity. This very simple equation leads to incredibly interesting and complex designs. The more you zoom into a projection of this fractal, the more interesting it becomes:
I imagine that most people exploring the fractal for the first time experience it as a colorful space that you can zoom through in a simulated space ship. I wanted to know what it would look like as a mountainous landscape, and I wanted to see it in real life.
I set out to generate a 3D model of what the fractal looks like, with the Z axis representing "the number of multiplicative iterations before the point on the complex plane assuredly escapes into infinity." This is how the fractals are usually colorized.
The first step was to find a section on the complex plane to visualize. This was the most fun part. I just used a section from Wikipedia for now:
I started with code to visualize the fractal as an image. I used a modified version of this script to generate my "reference image:"
The image intentionally looks like a spooky X ray of some amoeba. It has to be black and white - we're only dealing with three dimensions here!
Now I had reached the hard part: translating this image into a solid mesh. This is where existing software really helped me. I used Blender, an free 3D modeling and animation suite. Blender allows you to create meshes using Python scripts. Perfect. First I tried calculating the fractal right in Blender as I generated the mesh. This proved to be an impractical way to tweak the parameters. So I wrote a script to read back the image and create a mesh to visualize the image with the pixel brightness as the Z axis. (Scripts can be found here)
Here is what my generated mesh looks like in Blender:
Interesting! A few details: I first used a Gaussian blur on the reference image to make it less "spikey". I also upped the contrast a bit on the reference photo so the outer designs were more visible. Finally I didn't bother orienting my face normals in any direction, so I had to use Blender's Mesh->Normals->Recalculate Outside function. This gave me a solid mesh I could export to an STL.
Here's the model on Thingiverse: http://www.thingiverse.com/thing:209974/
I imported the STL into RepetierHost (which took about 20 minutes) and calculated the G code with Slic3r (which took another 30 minutes). This gave me time to warm up and calibrate my bot.
Here's the final outcome:
Specifically, I want to do two things with the device: create something no one has seen before, and experiment with different textures as a medium or a means to augment the qualities of an artistic piece. I think it would be interesting to see someone take a two dimensional piece and apply texture to it, so that the piece takes on different qualities when seen from different angles. That's sort of what I'm doing here, but something I'd like to explore further some day.
One thing that I've wanted to do for awhile is visualize the Mandelbrot fractal in three dimensions. If you are not familiar with the Mandelbrot fractal, you can read about it here. To summarize, it's a set of numbers on the complex plain such that when you continuously square and cube the numbers, it does not diverge into infinity. This very simple equation leads to incredibly interesting and complex designs. The more you zoom into a projection of this fractal, the more interesting it becomes:
I imagine that most people exploring the fractal for the first time experience it as a colorful space that you can zoom through in a simulated space ship. I wanted to know what it would look like as a mountainous landscape, and I wanted to see it in real life.
I set out to generate a 3D model of what the fractal looks like, with the Z axis representing "the number of multiplicative iterations before the point on the complex plane assuredly escapes into infinity." This is how the fractals are usually colorized.
The first step was to find a section on the complex plane to visualize. This was the most fun part. I just used a section from Wikipedia for now:
I started with code to visualize the fractal as an image. I used a modified version of this script to generate my "reference image:"
Now I had reached the hard part: translating this image into a solid mesh. This is where existing software really helped me. I used Blender, an free 3D modeling and animation suite. Blender allows you to create meshes using Python scripts. Perfect. First I tried calculating the fractal right in Blender as I generated the mesh. This proved to be an impractical way to tweak the parameters. So I wrote a script to read back the image and create a mesh to visualize the image with the pixel brightness as the Z axis. (Scripts can be found here)
Here is what my generated mesh looks like in Blender:
Interesting! A few details: I first used a Gaussian blur on the reference image to make it less "spikey". I also upped the contrast a bit on the reference photo so the outer designs were more visible. Finally I didn't bother orienting my face normals in any direction, so I had to use Blender's Mesh->Normals->Recalculate Outside function. This gave me a solid mesh I could export to an STL.
Here's the model on Thingiverse: http://www.thingiverse.com/thing:209974/
I imported the STL into RepetierHost (which took about 20 minutes) and calculated the G code with Slic3r (which took another 30 minutes). This gave me time to warm up and calibrate my bot.
Here's the final outcome:
Control an RC Car Over the Internet
A few months ago I set out to make an RC car controllable over the internet. I hosted a website from my laptop to make this happen. This is what you would have found on the about section if I left the site up (the car was getting a bit annoying). Source code can be found here
Real RC Race was a project to get an RC car controllable over the internet. I started at my local Radio Shack and bought the cheapest RC car I could find [1], as well as a breadboard, some transistors and LEDs.
I searched the internet for "control rc car from computer" and the first source I found was this [1]. This guy used a parallel port to run current on a circuit that flipped switches on an RC car's controller. At first I tried using a parallel port. Living in 2013, I did not own a computer with a parallel port. I bought a USB parallel port only to find that the microcontroller in the adaptor would provide an abstracted interface to the operating system, preventing one from physically setting bits on the wire like you could on an old school parallel port. One adventurer [2] used a transistor to latch the values written to the port on his USB adaptor, but this setup seemed unreliable.
I broke apart the car's remote control and soldered wires from the remote's switches to the breadboard. I also grounded the remote's batteries to the breadboard. From here I could control the car with copper wires. I set up 2N3904 transistors to gate these connections, as well as LEDs to show current was going through, and verified with a AA battery that I could use external power to control the car. The circuit remains roughly the same today.
Finally I resigned to make another investment and purchase an Arduino Uno. This was a breeze to set up, program and use. In a matter of minutes I was controlling the car using my keyboard through the Arduino's handy serial interface. I put 1K resistors and LEDs between the Arduino's digital pins and transistor gate. Originally I used the remote's AA batteries to power the antenna, but later connected the Arduino's +3.3V to a handily visible positive terminal on the remote, saving the need to replace its batteries in the future. The Arduino sketch is found below under "sauce". It's extremely straightforward.
Next I wanted to control the Arduino using Java. This wasn't terribly difficult; I found out that the Arduino IDE uses RXTX to communicate with the board and I grabbed a copy of this library. I had a Java program writing data to the serial port using RXTX.
Finally there was the the task of running a Java server to talk to the board, and a client application willing to talk to it. At first I tried using standard Java Sockets and an applet in a webpage to connect to it. I had a server and console application client talking to each other using sockets and controlling the car. However, it turns out that building and signing an applet on Linux is not easy. I didn't care to write an entire applet anyway, and I don't think anyone really enjoys running an applet in a webpage.
There had to be an easier way to do this. I tried to see if I could just set up a raw socket connection to my server from JavaScript. It turns out you just can't do this, but you can come close with WebSocket [4]. Java EE provides WebSocket support, but attempting to install the Java EE SDK on my Linux laptop resulted in my screen turning blank. So I decided to go with jWebSocket [5]. This library works, but I think it was written by apes and the documentation is abysmal. Regardless, that's what I used in my project.
With a WebSocket connection to my controller server from a webpage, I was controlling the car from any computer. For the webcam I used Motion [6], which magically sets up a web server running on 8081 that shows a stream from your webcam. I just used my laptop's webcam.
Anyway, I hoped you enjoyed this story. All of my code is found below and you're free to view, copy, modify and use it, barring any restrictions from the dependencies I used. If you want to copy this project entirely, you'll have to acquire the hardware I described, and install jWebSocket, RXTX, Motion and Python (for the static web server) on your machine. I used Linux but I'm sure this setup will work on any platform. Cheers.
Real RC Race was a project to get an RC car controllable over the internet. I started at my local Radio Shack and bought the cheapest RC car I could find [1], as well as a breadboard, some transistors and LEDs.
I searched the internet for "control rc car from computer" and the first source I found was this [1]. This guy used a parallel port to run current on a circuit that flipped switches on an RC car's controller. At first I tried using a parallel port. Living in 2013, I did not own a computer with a parallel port. I bought a USB parallel port only to find that the microcontroller in the adaptor would provide an abstracted interface to the operating system, preventing one from physically setting bits on the wire like you could on an old school parallel port. One adventurer [2] used a transistor to latch the values written to the port on his USB adaptor, but this setup seemed unreliable.
I broke apart the car's remote control and soldered wires from the remote's switches to the breadboard. I also grounded the remote's batteries to the breadboard. From here I could control the car with copper wires. I set up 2N3904 transistors to gate these connections, as well as LEDs to show current was going through, and verified with a AA battery that I could use external power to control the car. The circuit remains roughly the same today.
Finally I resigned to make another investment and purchase an Arduino Uno. This was a breeze to set up, program and use. In a matter of minutes I was controlling the car using my keyboard through the Arduino's handy serial interface. I put 1K resistors and LEDs between the Arduino's digital pins and transistor gate. Originally I used the remote's AA batteries to power the antenna, but later connected the Arduino's +3.3V to a handily visible positive terminal on the remote, saving the need to replace its batteries in the future. The Arduino sketch is found below under "sauce". It's extremely straightforward.
Next I wanted to control the Arduino using Java. This wasn't terribly difficult; I found out that the Arduino IDE uses RXTX to communicate with the board and I grabbed a copy of this library. I had a Java program writing data to the serial port using RXTX.
Finally there was the the task of running a Java server to talk to the board, and a client application willing to talk to it. At first I tried using standard Java Sockets and an applet in a webpage to connect to it. I had a server and console application client talking to each other using sockets and controlling the car. However, it turns out that building and signing an applet on Linux is not easy. I didn't care to write an entire applet anyway, and I don't think anyone really enjoys running an applet in a webpage.
There had to be an easier way to do this. I tried to see if I could just set up a raw socket connection to my server from JavaScript. It turns out you just can't do this, but you can come close with WebSocket [4]. Java EE provides WebSocket support, but attempting to install the Java EE SDK on my Linux laptop resulted in my screen turning blank. So I decided to go with jWebSocket [5]. This library works, but I think it was written by apes and the documentation is abysmal. Regardless, that's what I used in my project.
With a WebSocket connection to my controller server from a webpage, I was controlling the car from any computer. For the webcam I used Motion [6], which magically sets up a web server running on 8081 that shows a stream from your webcam. I just used my laptop's webcam.
Anyway, I hoped you enjoyed this story. All of my code is found below and you're free to view, copy, modify and use it, barring any restrictions from the dependencies I used. If you want to copy this project entirely, you'll have to acquire the hardware I described, and install jWebSocket, RXTX, Motion and Python (for the static web server) on your machine. I used Linux but I'm sure this setup will work on any platform. Cheers.
- http://www.radioshack.com/product/index.jsp?productId=16767136
- http://www.jbprojects.net/projects/rc/
- http://www.linuxquestions.org/questions/linux-hardware-18/usb-parallal-adapter-i-o-trickery-836663/
- http://en.wikipedia.org/wiki/WebSocket
- http://jwebsocket.org/
- http://www.lavrsen.dk/foswiki/bin/view/Motion/WebHome
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