AMOS Gets a Makeover

The code for AMOS's GPS navigation was tweaked after last week's blog post, and the navigation test at Woolastook was repeated. This time, I think AMOS properly went to each of the GPS waypoints, although unfortunately I don't have definitive proof, since a bug introduced in the software prevented the minute-by-minute saving of GPS coordinates to the ship log file. Although the track of the boat was faster, with less stopping to check bearings, it was still weaving back and forth too much, basically over-compensating the thrust in each direction to maintain a particular heading:

https://youtu.be/eVdl9HlaNSk

So the software was tweaked some more, the log file bug for GPS coordinates was fixed, and I think it should work a lot better now, but when making some mechanical alterations to the boat this past weekend, I had forgotten to disconnect the boat's +5 and +12 V power supplies. Since there remain a number of small circuit boards that are still loose in the "hold" so to speak, these tend to slide around a bit when I'm rotating the hull, mounting propellers, etc. At first I thought the burning, toxic smell was some chemical that Kelly had added to our pool (I was working on the pool deck at the time) but then the hard truth hit, that some unfortunate circuit had shorted out inside of AMOS. This time it was the GPS circuit board. What appeared to have been a power transistor on the GPS board had been reduced to blackened ash. I'm guessing that one of the GPS power rails probably shorted out on a nearby propeller speed circuit board. So the loss of GPS has prevented field navigation tests for a few days, but a new board is on its way from China and will hopefully be here by week's end.

Speaking of mechanical alterations, check out the makeover that AMOS has undergone this week:

The wooden framework was replaced by threaded rods, nuts, washers, 4 U-bolts, aluminum sheet metal, and lots of JB Weld Epoxy. Accessing the hatch now requires removing 4 wingnuts, but I think a latching mechanism connected between the front two threaded rods, should allow someone to more easily lift the solar panel. Having the propellers closer to the center and a bit further apart has made the boat a bit touchier for turning, and will require some additional refinement to the navigation software.