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A few weeks ago, John had some integration trouble, so he created a "debug" mode for the system. Might as well try it, he says to himself and a few taps later he is on the command channel of the Robo-Monitor app. A quick tap sends the "debug" command, and the other quad lands. A flood of new data appears on the screen and John drills down into the QUAD2 subsystems. On-board sensing seems good... battery voltage is nominal... internal temperatures are valid... embedded processors are running... plenty of free RAM... wait... looks like position isn't correct. John picks up his ill craft and notices that velocities remain zero.
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