Isopropyl Alcohol Fixes Everything

This competition is starting to feel a bit more intense. Since we were the third team to pre-qualify by driving through the gate yesterday, we got third choice of competition times today. We chose 12 o'clock noon to give ourselves to time to prepare before and after.

After some hard decision-making, we decided to eschew the vision events in favor of concentrating on the hydrophones and detecting the pinger. We also decided to toss the floating antenna that attached to our sub with a long, waterproof cable. Instead, we made a last-minute trip to Home Depot for a long, indoor antenna that would attach directly to the sub. It worked like a charm.

Thirty minutes before our competition time, we had a moment of panic when the sub's right motor wouldn't turn on (unless you poked it). Also, the sub was leaking just a tad. The guys quickly took the sub apart and discovered that the motor drivers needed to be switched. The leaking was taken care of with a few squirts of isopropyl alcohol and a liberal application of a toothbrush. (Over the course of this competition, I've come to the realization that isopropyl alcohol (IPA) will fix just about anything. Hydrophones not working? Clean the boards with IPA. Motors not working? Clean the boards with IPA. Software error? Re-code and then clean everything with IPA for good measure.)

We rushed up to the competition dock at the last possible minute, where Dave, the man in charge, grinned and tapped his watch. "12:14." (We had until 12:15.) However, we were surprised to find out that the rules of the pinger were different than we though. One of two pingers (with two different frequencies) is turned on, and the robot is supposed to find the pinger, no matter which frequency is going. We thought that at the beginning of the run, Dave would reveal the frequency of the pinger. Oops. Unsure that we could complete the hydrophone task under these new conditions, we elected to do only the simplest task of all: driving through the gate. We managed it easily, twice. Of course, only the last run counts towards points.

Now the guys are focusing on making the hydrophones work under the new conditions, a task that they believe is entirely possible.

Next up on the schedule is a practice run at 2:30 and static judging shortly thereafter. In static judging, the judges will come by the booth and examine our sub while the guys explain the ins and outs of its design and technology. This judging determines who gets first choice of competition times tomorrow, so we're all planning to be at our most charming, witty, and knowledgeable when the judges come by.