AMOS Takes a Dip

I spent about another day trying to get Bluetooth communications to work between AMOS and my iPhone before giving up. I think it can be done, probably using the iOS Core Bluetooth libraries for Bluetooth Low Energy (BLE) communications, but it looks like a lot more work than what I'm willing to dedicate to it at this point. I believe getting Bluetooth working between the Android phone and AMOS won't be too bad; it should be similar to what I did a couple of weeks ago, getting Bluetooth software working between the PC and AMOS.

To that end, I've started writing a version of BoatCaptain for the Android phone. There isn't much functionality in it yet, but here is a cool screen shot to look at:

The PC version of BoatCaptain also now has a stop sign button, for immediately cutting power to the propellers. It makes driving AMOS quite a bit easier, since it gives the driver a sort of "mental" reset so that they immediately know the state of the propellers (i.e. stopped) without needing to look at the propeller speed controls in the graphic user interface.

The PC version now also gets GPS, magnetometer compass, roll & pitch angles, and temperature from AMOS. These were initially set to update every 2 seconds, but it was found that this tended to cause connection problems over Bluetooth, so the interval was reduced to once every 10 seconds for Bluetooth. The data rate should be fairly small, so I'm not sure why the Bluetooth connection was adversely affected by the 2 second update rate. Internal to AMOS, GPS data arrives once every second, and the compass heading, pitch, and roll angles and temperature are collected at 50 Hz, with a 5 sample running average. So this should allow for pretty good real-time navigation later on. The compass data looks reasonable, probably to within 20 degrees or better, and I verified that the GPS latitude and longitude changed slightly when I carried the boat around the backyard.

The iceberg in our pool has almost melted. Here is a video that Kirsten took of me carefully piloting the craft around the perimeter of the berg: https://www.youtube.com/watch?v=p4Y3qhnZCIo  The interior of AMOS also now features a 2.5 kg weight velcroed to the bottom of its interior for ballast; I think it helped a little, although it could probably use even more. The boat is already a bit heavy to carry though, so I'm reluctant to add too much. After this video was made I did some more testing / fooling around and somehow lost the network connection while AMOS had its propellers set to the maximum backward speed. It gyrated a number of times around the pool, out of control, but luckily I was able to grab a hold of it when it came close with one hand, release the cap with the other hand, and then unplug the power wire. Later on I changed the software so that it should kill the motors when the connection gets lost. Should probably also add a master power switch to the exterior of the boat for easier on / off control.