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Building the PC Power Monitor

Ok, D-Day. Time to dig up my Press-n-Peel PCB transfer film and Ferric Chloride.

In the mean time I added a jumper to the circuit design so I can disable the buzzer if it became too annoying.

Designing the PC Power Monitor - Part II

In Part One of this project I developed a test circuit that proved that it would all work. In Part II, I actually redesign the bread boarded prototype into the final product.

Designing the PC Power Monitor - Part I

After the near mishap with the last GPS bush walk, I have pondered how I was going to monitor the battery power usage. This blog is my first go at it.

Taking the GPS for a walk in the bush

The next day I set out to map some of the roads and tracks around a patch of Bush that I have been frequenting for a few years - recording native Orchid growth etc.

Here is the voltage recordings of the battery:

11:30 13.25V (No load)

11:32 12.63V (PC On)

14:45 strong electrical burning smell noted!

14:50 9.8V (No Load)


Talking the GPS for a drive

Ok, time to go for a walk and a drive...

I checked out my last lot of GPS code from the SWASC subversion repository and uploaded it to the MARK I mini-ITX PC. I then went for a walk around the park at the back of the house. The PC and GPS where running from a common 12V 7A Sealed Lead Acid (SLA), battery. The first walk lasted 1 hour 40 minutes. I noted the voltage drop over this period:

13:40 12.28V (on load)

14:00 12.14V

14:40 11.96V

15:00 11.88V

15:05 12.00V (no load)

Power Distribution board

Back in March 2006, I went to run the PC for something, and realised that it would be really handy to have a power distribution board. This would allow me to quickly unplug all the different modules.

This is what I came up with. It's still not built, as I will make the PIXAXE-28 controller board at the same time, since this one is pretty small.

Here is the schematic diagram of the board:


Here is the PCB board layout:

Re-Mapping my GPS data

Well, it's been a while, but the SWASC wheels (propeller?) are still turning.

This afternoon I have been discovering how to use a Freeware GIS mapping program called MapWindows. At the moment, it pretty well does all that I need a GIS program to do.

Steering the Mark-I boat

Ok, this has had me stumped for some time, however, writing up the last blog, I had a flash back to the tourist Amity Brig down at Albany. The steering ropes and windlass are all out in the open, so the kids and dad's love to peer over the edge and see how moving the wheel makes the rudder turn.

This is my go at it. Well, at least it's a start.


Pool testing a model of the Mark-I

I was concerned about the how well the Mark-I might turn with the motor mounted midship of the boat, so I decided to build a small 30cm model using 25mm PVC tubing. Out came the scrap pieces of MDF and hot glue gun. I had a CD-ROM drive lying around, so I dismantled it, and extracted the head positioning motor. Part of the case was cut up to became a dodgy looking propeller. The shaft was constructed from two 25mm nails, soldered together.

Drawing the Mark-I Hull Assembly

The concept 3D drawing has been completed!

I have a friend who has a copy of AC3D, a easy to use CAD package. With in an hour or so he had taken my hand drawn chicken scratching and drawn the concept model of what I was after.


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