Minus One Box

The last week was mostly spent on modifying AMOS to have a lower profile in the water, so that it is not as strongly affected by high winds. This was done by moving the electronics from the 3rd largest box into the 2nd box which was only about half full and had some room to spare. Work was also done to move the power switch from the top of the 2nd box to the side, and to re-wire it to make use of a waterproof gland. After having rain nearly every day this week, I can say with some confidence that the new switch design is waterproof. The old design was not, and I think the box would have been half-full of water if the old switch were still in place.

I traced around the two electronics boxes with a sharpie and then used a drill to cut out a rectangular portion of the fibreglass shell. Then it was a time consuming, mind numbing chore to dig out the pink foam insulation 1 cubic centimeter at a time with a pair of large pliers.  Here is a picture of the half-finished work:

I basically just dug down to the depth of the bottom layer of pink insulation. This bottom layer was quite thin at either end of the boat where the boxes were located, since that was where the surfboard shape started to taper.

Here is the finished result, as seen in our pool at night:

The yellow stuff in front of the box is globs of old glue that were used to hold the box to the board in its former location. The box had to be moved back a bit from the front to an area where the board was thicker.

I have avoided going out for a field trial the past few days due to poor weather, and decided to focus instead on trying to solve some strange communications problems with the Android phone to transmitter box to boat link. Sending and receiving of short commands less than about 100 bytes work great, but trying to send and receive larger things such as image files has proven more challenging. For some reason that I haven't been able to figure out, bytes are getting periodically garbled and I'm not sure why. I use sync bytes, checksums and a sort of packet re-try system which gets the data to arrive eventually, but it's painfully slow. I thought I had it for sure tonight when I discovered that the 3 AA alkaline batteries in the transmitter were down to about 1.25 V each, but that wasn't it at all. Brand new batteries worked exactly the same. I also thought I would fix it by changing from 115200 bps to 9600 bps, but that didn't help at all either. Sometime later I'll try using a PC to transmitter to boat link to see if that works any differently (i.e. bypass the Bluetooth link to see if that helps).