Automating Pool Chlorination

After a year of dumping various sorts of chlorine into the pool, I finally got all the bits and pieces together to automate the chlorine addition process. The key element that pushed me over the hump was learning I could open a COD account at Hill Brothers Chemical to buy commercial quantities of high [...]

Pool Water Chemistry and Testing

This whole pool thing is new to me and it’s time to organize my thoughts on what/how/when things need to be done.

The BBB (Bleach, Borax, Baking Soda) method looks like the most straight forward method for maintenance. In a nutshell, do the following:

Know your stabilizer concentration:

You have to know how much stabilizer (CYA, Cyanuric Acid) is [...]

GE Frontload Washer Door Gasket Replacement

After ~5 years of reliable service from our GE Adora front loading washer, the first repair it needed was to replace the torn door gasket. Upon finding a pool of water under the washer, I was rather miffed that the material would fail so catastrophically. However, upon opening the bottom panel, I found the [...]

Arduino battery capacity tester

My first Arduino project was to build a battery capacity tester. I’ve got a box of rechargeable AA batteries, and it seams they’ve been less and less effective. Since most applications require 4 batteries, invariably one problem battery makes the rest of them look bad.

The Atmel ATMega328 microcontroller has 6 analog inputs with [...]

iPhone software 3.0–email full resolution pictures

I just stumbled on a new feature of the iPhone 3.0 software — using the copy/paste feature, you can send a full resolution picture in an email:

In the picture browser, tap the picture to highlight it and make the “copy” button appear. Tap the copy button.
Close the picture browser app.
Open email app
Compose a new email, and [...]

Building pannier hardmounts for a BMW F800

The thought of spending over $1k for the BMW panniers (that aren’t even water proof) is totally absurd to me. Other aftermarket options add up to >$700+ by the time you buy the special F800 adapter frame for them.  I guess I just couldn’t justify such expense for something that will only get put on the [...]

Install Givi E370N top case on BWM F800ST

The universal mounting/adapter plate that comes with the Givi E370N top case gives many options for bolt placement, but, unfortunately the rest of the hardware is inadequate to work on BMW F800ST luggage rack.

My goals for the install:

No drilling/modification of the luggage rack
Offer some amount of cushion/padding to prevent the hard case from marring the paint.
Position [...]

On tankless hot water heaters and sizing a natural gas pipe

Researched tank-less hot water heaters and their voracious demand for natural gas. Decided to go for the Takagi T-K3-OS because: 1) it is for outdoor installation — no fancy exhaust flume required, and 2) its *minimum* BTU rating of 11K was one of the lowest I’d seen (considering that the maximum side was more than capable).

I [...]

Network tar using SSH

Never realized how easy it is to duplicate a directory tree from one machine to another through the network without building an intermediate tarball and finding room for it and the original files all at the same time. Simply pipe the tar command through ssh and untar it on the fly.

For example, suppose we have direcotry [...]

More resources on low-power computing

The Via Epia mini-ITX boards are some of the lowest power around. has a power simulator that’s good for comparing the differences in boards.

Although, I’ve noticed that the VB7001G board I’m using has inconsistent results on the calculator — 16.23 watts idle versus 13.92 in “network mode”. Take it for what it’s worth.

While [...]