Little Wire SMD

I came across the Little Wire a few months back. I thought it was a pretty cool idea to have a few GPIO's accessible over USB. More than that, it also offers several serial protocols (I2C, SPI, etc), dual channel ADC, and even works as an AVR programmer, all in a neat little package! To make it even littler, I designed an SMD version of it.

I especially liked it for using a software implementation of the USB protocol on an attiny, which means I should be able to use an attiny in place of the much larger (and more expensive) FTDI chip.

(Mostly) Organized Resistors in 20ish Drawers

Organizing electronic components is important if you want to spend more time building prototypes than looking for the right resistor. The problem is, there's just way too many to organize without spending a ridiculous amount of money and space on a billion little drawers....

Sous Vide Part 1: What and Why?

I was introduced to the concept of sous-vide cooking one day while listening to Science Friday. In a nutshell, sous-vide cooking involves vacuum packing your food (usually meats) and placing them into a temperature controlled water bath at lower-than-normal cooking temperatures for longer-than-normal cooking times.

Efficiently Reading Quadrature With Interrupts

Once you start wanting to control the position of a motor through feedback control, you will likely end up using a rotary encoder as the feedback device. Encoders can be broadly categorized as:

• Absolute position
• Incremental position

Absolute position encoders will tell you what the angular position is all the time, even between power cycles. Most use "grey code" (a modified form of binary) with several "tracks" (bits) to read position.

Incremental position encoders will tell you what the angular position is, but only relative to where it was when you started paying attention (usually on power-up). Two common types of incremental outputs are:

• Incremental (clever name)
• Quadrature

Incremental is rather useless for position control because it doesn't give you any information about what direction you are turning, just that you are turning. Quadrature encoders give you direction as well as incremental position. This article deals with efficiently reading quadrature output on an Arduino by utilizing external interrupts and some AVR bare-bones code.

Why another blog on the blogosphere?

I like to build stuff. I find joy in spending countless hours tinkering on various projects to do things that I think are cool, even if they are already commercially available. There's something about knowing how and why something works, and recreating it myself. Plus, I think the cranial exercise is good for me.

I'm a recent graduate from the University of Utah Mechanical Engineering department. There I was introduced to the field of Mechatronics which quickly captivated my heart. I decided to do the extra coursework and projects to earn a mechatronics certificate along side my bachelors degree. Now, as a "real" adult, when I come home from work I spend a fair amount of my free time delving into various projects--partly to do things I find useful, and partly to expand my knowledge of the subject.

I've decided to create this blog as a way of making available the information I learn while working on these projects. The hope is that I'll provide enough detail for others to recreate what I've done, plus a healthy dose of theory where applicable.

While I intend for non-material things to be freely available (knowledge, plans, code, etc.), there are material objects, some of which I have custom made (i.e. circuit boards with a minimum quantity to order), that I will make available to purchase. I don't plan to get rich off of anything I post here, and the things I do sell will be just enough to cover manufacturing costs and maybe a little extra to fund additional projects.

Welcome, I hope you like it here.