In a previous post, I discussed our mainboard approach for ArduPilot Mega. In this post, I'd like to share our thinking about the expansion boards ("shields", in Arduino-speak).
As you can see in the above diagram, the core ArduPilot Mega will consist of two layers, just like the current ArduPilot. The core autopilot board will remain constant, while the IMU board will come out in versions, improving as sensor technology evolves. But there is also the option to add a third layer, which is an expansion board for additional functionality.
We will break out as many I/O (analog and digital) pins as possible to the expansion board, along with at least two serial ports. Some of the boards, such as the DIY sensor board, will be dual voltage.
Some of the boards proposed above may be ones for which there would be enough demand that we'd make and sell them ourselves. Others may be created by the community. ArduPilot is an open standard, like the rest of Arduino, so we'd like to encourage people to come up with their own shields, just as the community has done with the core Arduino boards.
So what do you think? Have we missed any obvious expansion board candidates? Any design decisions we should be making with the core ArduPilot Mega board or IMU to allow for more expansion options? (Remember, size is at a premium, so suggestions that require bigger or more expensive mainboards tend not to carry the day)