Today I primarily did two things: programmed the software library for the Dual Motor Driver add-on, and sort of blew up my one assembled prototype board.... "Why?" or "How?" you may ask; by accident and because I plugged a battery into it backwards. It should be said, though, that the Tilty Quad that the add-on was connected to survived unscathed.
To explain the issue, on most of the add-on boards and the Tilty controllers, the battery power goes directly to a reverse-power protected voltage regulator before going to any of the other components on the circuit board. However, since the motor driver is the one add-on that makes use of the full battery voltage, some components were directly affected by the reverse power. And although nearly everything seems to have survived (though there was a "pop" and a small amount of smoke), the I2C circuitry in the microcontroller is no longer functional. So, although the board is still useful for testing motor control through direct programming, it can no longer communicate with the Tilty control boards.
In other, less destructive, news, lots got done on the programming of the software library for the motor driver add-on. It is now communicating with the Tilty controllers, reading and communicating the encoder values at their full speed (which was a concern before and is fantastic to have working), as well as reading and writing motor power values. This is a big step towards getting a fully functional TiltyWay put together.
I also decided to test the use of multiple add-on boards together; specifically the advanced IMU, R/C Receiver Adapter, and Dual Motor Driver. And I'm pleased to say the test went very well. I discovered a minor problem with the I2C lines for the receiver adapter and motor driver, but it was easily fixed simply by changing two resistors. And after that everything worked together beautifully. I've somewhat outlined the test setup in the diagram below.
Also, I expect to have the updated R/C Receiver Adapter prototype and the first Tilty Omni prototype by (hopefully) Thursday. I do know they shipped from the PCB manufacturer today and shipping usually takes two days. The Tilty Omni will be interesting to test as, even though it is a first prototype, it incorporates everything I've learned from designing the Tilty Duo and Quad. On the other hand, it required almost half again more electrical connections (of which none can be allowed to cross) in a space essentially no larger than that of the Tilty Duo and Quad. It's somewhat like designing and solving a two level maze with numerous paired entrances and exits, without allowing any paths to cross in the same level and with as few level changes as possible in any given path.
But that's all for tonight I think, as it is now technically morning. Today has been a long and productive day of work (12+ hours), and I look forward to continuing it tomorrow (now technically today) and Thursday when I receive the new prototypes.