DARPA Grand Challenge 2005 set for October 8, 2005. The second DARPA Grand Challenge, a field test designed to accelerate research and development in autonomous ground vehicles that someday will help save lives on the battlefield, will be held on October 8, 2005.  

The Seattle Robotics Society holds a ROBOTHON event every year at the Seattle Center.  This year there will be a MINI CHALLANGE inspired by the GRAND CHALLANGE. 

SRS/SERVO Magazine Robo-Magellan

A robot has three chances to travel from point A to point B in the shortest time possible. Score is improved by visiting various bonus waypoints along the route.

The robot may be of any size or shape as long as it is not constructed in such a way as to damage the environment or other robots. See "Safety" for other restrictions. No robot may more than 50 pounds nor may it use an internal or external combustion engine.

Robots must be autonomous. Remote control is not allowed.

The course will be outdoors with both natural and manmade terrain and obstacles. The terrain may include pavement, dirt, small rocks, grass, hills, gullies, trees, curbs and weeds. This list is not exhaustive. The robot will not need to traverse a water obstacle to complete the course although weather conditions may make some surfaces wet and/or soggy. The contest will not necessarily be postponed in the event of inclement weather.

Robots will be placed behind a starting line prior to each run. The destination and bonus waypoints will be designated with latitude/longitude coordinates and marked by 18", orange, plastic traffic cones.

The total straight-line distance between the start and destination will be less than 300 feet however the shortest route may be longer due to obstacles. The route taken from start to destination, including bonus waypoints, may be significantly longer than 300 feet.

http://www.robothon.org/robothon/challenge.html

The mini challange has a few very interesting challanges within the challange. 

Travel from point A to pint B in order to have a chance at winning.

Identify obsticals and avoid them.

Travel as fast as you can.

Be water proof, this is being held outdoors in Seattle, it rains a lot.

Identify an orange trafic cone.

Touch the traffic cone and stop.

Extra Credit on the course there will be several other bonus points for identifigin and touching other traffic cones on the course.

We started our project with an off the shelf four wheel drive RC (Remote Control ) Car from Radio Shack and hacked the board.  Doug Bell was able to draw a schematic for the board and determine where to hack in and attach a Basic Stamp Microcontroller.  North Seattle Robotics Group decided on the Basic Stamp because many of the students on campus are familar with this device, it is used in the electronics class rooms. 

A short piece of ribbon cable was soldered directly to a 24 pin socket.  The cable was cut just long enough to attach the Basic Stamp microcontroller and fold it up inside the electronics compartment on board.  We attached a nine pin RS232 connector to the socket as well.  A surplus on from an old computer worked very nicely.  The ribon cable, sockets, and many other parts were found at the House of Science http://houseofscience.com/.  There was just enough room to modify the housing of the RC car using a dremel.  Measuring the space and marking it with a pencil worked very well since the surface was black.  Pencil shows up shiny on a flat black surface.  Starting on the inside of the marked slot for the RS232 connector we dremelled out most of the the opening.  It is best to leave a few milimeters of material

So thirty minutes before the contest begins contestents will be given a file with the GPS coordinates of the START point and the STOP point as well as the bonus points along the way. 

The first challange will of course be getting those coordinates into the robot.  If things go as planned we will upload the data via a RS232 cable. 

Adding a GPS (Global Positioning System) to your robot can make it easier for your robot to get to where it is going, provided, of course, you have the coordinates. 

As part of a group buy at one of the SRS (Seattle Robotic Society) meetings our group purchased 3 Garmin  GPS 18 LVC.  They cost eighty dollars each including the shipping and handling.  The unit comes in bubble wrap and a cardboard box.  There was no manual, pamphlet, or brochure with the unit.  Fortunately we have the internet connected in our Robotics Lab.  From the factory web we were able to download information about the unit.  initially it looked like we would have to pay a few hundred dollars for the information we needed (NMEA0183  Standard, ASCI interface specification) but we continued to look until we found what we needed. 

For the Garmin GPS 18 LVC info goto http://www.garmin.com/support/userManual.jsp and enter the model.

The unit has a mounting screw hole (female) on the bottom side.  It is a metric thread and we did not have them in the lab.  When we set it on the metal table we discovered it was magnetic and designed to stick to stuff.  So instead of a mounting screw we found a ferous mounting plate to stick it to magnetically. 

The unit is round and measures two and a quarter inches across and just over a half of an inch tall.  It comes with a connecting cable that measures over nine feet long.  The end of the cable has a connector that is different from the ones we have in the lab.  The cable has eight wires, one of which is bear, one is a spare and six of them are attached to the six pin female connector.  The factory site made it clear the connector is installed at the factory for testing and it is okay to remove it and that doing so will not in any way invalidate the waranty.  Looking at the factory site we identified the type of connector [insert type of connector] and found a source for purchasing it [insert web site for connector].  We decided we wanted to work on it now so we decided to take advantage of the permision granted by the factory web site to hack off the connector.  (See Figure One) We saved the connector with the GPS box in case we wanted to use it later.  

From the factory web site we determined what each of the wires are for. 

1  Yellow  PPS    Pulse Per Second

2  Red      VN     Supply Voltage 4.0 - 5.5 VDC 60mA

3  Black    GND  Ground

4  White    TXD   Transmit Data

5  Black    GND   Ground

6  Green    RXD   Recieve Data

We are working with the Basic Stamp 2 microcontroller from www.parallax.com and so our next step was to determine how to attach the GPS to a Basic Stamp Board of Education. 

Factory specs call for a 1 amp fuse in line with the [power supply?] we were going to use an inline fuse connector but decided to go with a liter weight model wich is just a fuse with sturdy wire attached.  We had one in our lab already to go.  The sturdy wire was a little too big for the bread board so we got out the handy dremel with a fine sanding wheel and trimmed it down a few nanos until it fit just perfectly.  If you do not have in line fuse connectors or the soldered  version you can make one very easily by soldering a couple of wires to each end of a fuse.  Be sure to pick wire that will fit into your bread board if you are doing this type of project so you can avoid the dremel step. 

Having the GPS connected to the Basic Stamp microcontroller was the begining.  The next step was to write some code to get some communication between the GPS and the microcontroller.

The "TECHTRONS LAB" has been a part of North Seattle Community College history.  This room has been in the control of the students since as long as anyone can remember.  The administration had decied turning this student run electronic lab into a plumbing closet for the facilities has more educational value.