Posts Tagged “Mission Control”

REDIS

After a lunchtime conversation with a friend of mine, I ditched some of the earlier design considerations around message-passing and MQ-based systems in favour of the NoSQL database Redis.

Redis is an open source, BSD licensed, advanced key-value store. It is often referred to as a data structure server since keys can contain strings, hashes, lists, sets and sorted sets.

That’s according to the official blurb on the web site, at least. It has several interesting components which are useful for Beoga Beag. It has a rudimentary pub/sub architecture pattern, it is extremely lightweight, it stores its database in memory rather than on a disk (so it’s less likely to burn through the Compact Flash file system), and it has an “append-only file” (AOF) archive mechanism.

Read More

Mission 001 - Galway Bay

As the hull is now watertight, and we’re mere weeks away from having a sealed hull with keel and rig, it’s OK to start looking at actually getting this thing to sail.

Up until now, I’ve been somewhat obsessed with getting the physical aspects of the boat to a certain juncture. The reasoning is simple; until there’s a boat, all of this other stuff is just a waste of time. Well, now there’s a boat…

Read More

The Software...

The FreeBSD Daemon, ready to take on Neptune and his cohorts.
The FreeBSD Daemon, ready to take on Neptune and his cohorts.

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.

Read More

BB Phone Home.

There is a race requirement which states that “Any boat which fails to transmit for more than 10 consecutive days will be disqualified.”

While there are a number of ways of reporting position data back to Mission Control, from elaborate HF transmitters through to simple satellite position locators, we’ll be using a Rock Block satellite modem. These devices can send byte sequences back to dry land via the Irridium satellite network. We will be sending four updates a day, of exactly 250 bytes each. Each message will include two or more payloads.

Read More

The Main Systems Design

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. This is the control board, also known as Otto or Otto von Helm, to give him his full title. Otto will most likely be assisted by Igor, in charge of power management and the boat environment. It is Igor who will turn on and off the other systems on board, including the main system (Mother).

Read More