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The Main Systems Design

By Dermot Tynan, over 8 years ago.

In terms of the system architecture, we're planning on using two separate computer control planes to manage and steer the boat from start to finish.

At the lowest level, a custom Atmel (ATmega8) board will act as a basic "autohelm", driving the boat to a specific True Wind Angle or TWA. As the breeze shifts, so too will the boat, to maintain that TWA. This is a basic PID algorithm for controlling the rudder and mainsail in relation to the specified TWA and is very similar in design and implementation to your average sailboat autohelm.

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"Mother"

By Dermot Tynan, over 8 years ago.

The main computer on board Nostromo in the film Alien was called Mother. It seems only right that we should call our main processor by the same name.

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Battery and Solar Design

By Dermot Tynan, over 8 years ago.

There will be at least two Vcc busses on board. Labeled, oddly enough, as Vcc1 and Vcc2. The difference between them is that Vcc1 is always on, at all times, and Vcc2 (through VccN) are selectable by Igor.

The main processor runs off Vcc2, but Igor (and Otto) both run off Vcc1. In situations where voltage levels are critical, Vcc2 will be switched off and the boat will continue on whatever course had previously been set, until either voltage levels are healthy, the specified "wake-up" time has elapsed, or there are critical issues which require Mother to get involved. A critical situation could be something like a dramatic wind shift, or an error such as a mis-reading from a sensor.

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The Software...

By Dermot Tynan, over 8 years ago.

I've been asked recently, about the software platforms used on board Beoga Beag. This seems as good a time as any, to talk about the various layers. As mentioned previously, the lower layer is a custom board, running an ATmega8 Atmel processor. The software (Igor and Otto) is custom-written in C for the boat.

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Hello to the Little Red Daemon

By Dermot Tynan, over 8 years ago.

After much tweaking and hacking with configuration files and kernel build options, I finally have a FreeBSD 8.3-RELEASE kernel and install running on a Wrap board. Technically, it's NanoBSD, which is a scaled-down FreeBSD install, which boots from Compact Flash. The WRAP board is the PC Engines forerunner to the ALIX. When National Semiconductor and AMD stopped making Geode chips, the guys at PC Engines had to stop making their very popular WRAP board. I still have a few of them tucked away, for emergencies such as this.