Sailboat Guidance System

By Dermot Tynan, over 9 years ago.

A quick look at the almost-complete Sailboat Guidance System (SGS). The board on the left is Igor. Otto is on the right, and the main CPU (Mother) is hidden underneath. The ribbon cable brings all the I/O to and from the boards. The red insulating tape is to remind me of some of the last remaining wires which need to be connected. You can also just about make out the DC/DC converter which is just underneath the ribbon cable at the bottom of the picture.

  • October 27, 2013
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The rubber hits the road. Sort of.

By Dermot Tynan, about 9 years ago.

Due to other, exciting distractions (which I will mention in a later post), I haven't had a chance to keep the blog up to date. Still, work progresses on the boat, and that's the important part. Last month, with the keel now in its new position about 30mm further back along the hull, and sealed into place, it was time to add the electronics board.

  • January 6, 2014
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Hello to the Little Red Daemon

By Dermot Tynan, almost 10 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.

  • March 30, 2013
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Good morning, Mother!

By Dermot Tynan, over 9 years ago.

As of about an hour ago, Igor and Mother exchanged communication. It was awkward, stilted communication, like a first date, but they talked! One of the issues with the RS232 stream is that the kernel is chatty. I've suppressed a lot of the boot-up messages, but there are still all those /etc/rc startup messages. As the ALIX board only has one serial port, those messages are sent to Igor. To avoid sending Igor into a tail-spin, or more importantly, sending the boat into a tail-spin, Igor ignores all RS232 output when Mother boots, until the magic word is sent over the wire. The magic word is XYZZY. Anyone want to try and figure out where that comes from?

  • August 21, 2013
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Simulations

By Dermot Tynan, over 3 years ago.

Carpenters like to say "measure twice, cut once." In the software world, we make extensive use of unit tests and end-to-end tests. But the North Atlantic is no friend to small boats, and there's not a lot of end-to-end testing which can replicate the vagaries of the wild Atlantic. To that end, we use simulations. Simulators can be used to throw all kinds of real-world problems at a piece of software, and measure the response.

  • May 15, 2019
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