Development Status
Over the weekend, I got the stand assembled and wrote up some instructions which you can check out here Stand Assembly.
The cut acrylic came back last Friday and I think it looks great! When I get time, I'll get some photos and instructions for assembly written up. -dak
I'm picking up the acrylic sheet and Weld-On #3 (faster set time) and delivering the plastic to the cutter. The price per stand will be about $253 going this route. I'm sure there are ways to reduce this, but for 2, let's get them done! I hope to get the cut parts back next week and then work through installation and document techniques and tools I'll use to get a good result. -dak
I researched acrylic "welding" using solvent based solutions like Weld-On #4. It turns out that the laser-cut edges are polished and also hardened. They aren't suitable mostly because the hardening makes the edge brittle. The solvent will cause crazing and the cracks can work their way into the piece. We need a non-heating means to do the cuts, like... waterjet! I have a local shop that I'll be contacting for a quote. -dak
In the past couple of weeks, the interface between the Arduino and Create have been spec'ed and tested. Wiring is in the hardware portion of the wiki. The acrylic stand has also been refined and submitted for quote. -dak
The Mega2560 has been mated to a DB-25 for connecting to the dock connector. Serial port 3 is wired in and we've run some demo code that controls LEDs and reads the bump sensors, then attempts to dock (once a bump is detected). Need to allow the Arduino to control the iRobot Create power on (one digital out connected to dock pin 3 should do it!) -dak
More parts ordered! We're ditching the iRobot Command Module because of it's lack of I/O options. We require a dedicated USB link to the netbook and active serial connection to the create. The I2C link hasn't been working out, so we've ordered an Arduino Mega2560, which can act as a low level controller, leaving the high level communication and control functions to the netbook. Anybody want to buy a couple of Command Modules, like new? -dak
Some code is checked in that provides a web interface to control camera pan/tilt. It is very basic, using GWT buttons. Use "ant server" to compile and run on port 8080. -dak
The LinkM interface should work, but haven't got there yet. We should be able to use avr-dude and avr-gcc to get code onto the command module. Good progress on the "stand". I'll get a rendering when I can. Working with a laser cutter to get it made in 1/4 inch acrylic. -dak
The command module that we're using is designed to communicate with the USB port, or the iRobot Create. The USB connection cannot be used for I/O during program execution, so we need another communication channel to connect the netbook. I2C is an established standard which supports high speed serial communication. The command module is a lot like an Arduino and the Wire library for Arduino can be used to mimic an I2C slave. The LinkM interface provides a USB->I2C interface which should allow the netbook to address the command module during robot operation. -dak
Based on a design I'm working on in 1/4 inch acrylic, I'm estimating the design to come in at 6.5 lbs. I hope to reduce this by the common engineering weight reduction technique known as "swiss cheesing". In other words, strategicly placed holes that don't sacrifice the structure, but reduce the total amount of material used (and thereby the weight). Currently transferring measured hand drawings into SketchUp. -dak
The iRobot Create parts have arrived! Time to play with locomotion code! On another front, looking at using aluminum vs acrylic for the support structure. It will greatly affect the design. Aluminum is 165 lbs/cu.ft., Acrylic is 73.6 lbs/cu.ft. It seems like the plastic is much lighter in general, but also less rigid. There are 2 designs we're considering. With plastic, it would be 2 side supports with a center cross member to tie the whole thing together, plus a shelf on the top. For aluminum, we'd probably use a mast design with some thin-walled round or square tube at least 2 inches in diameter. I'll need to calculate the weights for each. Aluminum can be cut and bolted together at home, which is a big plus. Acrylic would be sent to the laser cutter, which would allow for some fairly creative designs. -dak
The repository contains some code for controlling the Orbit AF pan/tilt. This has been tested while another application was using the webcam for video. No driver conflicts! Next step is building up the web application to integrate controls into. http://www.youtube.com/watch?v=X7_0rpwHbQE -dak