Death in the Night

The propulsion and course correction software for AMOS went through several iterations this week, all in a grand effort to make the boat drive in a straight line. The first couple of iterations actually made things worse; I didn't even need to use my kayak for those as AMOS either veered off towards the bank to the west or traveled about 30 m and then spun crazily around in a circle. Last night, I brought the laptop with me, intent on coding and re-coding until things improved.

After a couple of tweaks, things did improve and AMOS drove through the cove in a mostly straight line. I think it covered this distance (~ 500 m) the fastest it had ever done. Once the boat left the cove though, the wind was much stronger from the west and the water became quite choppy. Although the boat was pitching and rolling quite a bit, it seemed to move with a sense of purpose through the water. Whenever it approached one of the GPS destinations though, it would often veer off, or double back. I'm guessing that perhaps it was moving too fast near the destination, but I'll need to have a look at the ship's logs later on to confirm this. At one point a freezie wrapper became lodged between the blades of the left propeller creating a loud noise and causing the boat to spin around in circles.
I removed the wrapper, but about 10 minutes later, AMOS mysteriously stopped meandering around and just stayed put. It was after 8:30 by this point, so I turned off its power switch, hitched on the tow rope, and pulled it back to shore. Looking inside the hatch I could see that the leak sensor LED was lit, so although no water was visible, some drops must have gotten in; not surprising I guess given the choppy conditions and the imperfect sealing that has been applied over various holes made to the top of the boat.The computer was still responsive and behaving normally though.

That night, I left the boat in the garage to dry out, but still plugged in to the battery since everything still seemed to be running normally, even though I guess a few drops of water had gotten in.

This morning I awoke to find the interior dead! Normally there are a host of red, green, and blue LEDs merrily blinking away inside the hull, but this morning all was dark. A quick test of the Lithium battery showed that its voltage was zero. Nada. Zip. Nothing. So now I have to figure out what to do. I'm not sure if the battery can be saved or not, or what might have happened to it. I'm wondering if perhaps last night's test might have pulled its charge down too much? And then maybe just operating the computer overnight was enough to fully deplete it? Or maybe the little bit of water that got in somehow caused problems? If it can be saved I'll need to find a wall charger I guess, since the solar charger that I use requires the battery to have enough charge to power the charger.

(UPDATE: AMOS is now back online thanks to a $70 sealed lead acid battery from Canadian Tire. It is significantly larger and heavier than the Lithium one though, so hopefully the manufacturer will respond to the email that I sent with some suggestions for how to bring it back. The ship's log and other operating system logs seem to indicate that a reboot occurred at the end of last night's test. I'm not sure exactly why the reboot occurred; possibly it was a result of the water intrusion. Just a few minutes ago I squeezed the little sponge on one of the leak sensors near a U-bolt that supports the left propeller, and a few drops of water came out. That's the only water I found inside though, and the only leak sensor that indicated a leak.)