Coffee Science and My Octane Barista Certification

I regularly find myself explaining to people about my experiences working at the most forward-thinking coffee shop in the city. To paraphrase my usual explanation: “Octane Coffee is dedicated to a continual evolution toward providing the best coffee possible by endlessly educating its employees and customers about the many facets of coffee cultivation, production, and preparation.” This education is founded on both technical training and technical knowledge of coffee. I’ve done an extensive amount of exploring through my exposure to the coffee world. Several of these experiences are documented here.


Pulling two shots during my barista certification. Photo by John Cole.
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More Shoes and Light Tent

I painted another pair of shoes, this time for my friend, Jaime Walker. I call them “walkers”. Rather lame, I know. I started with Vans KVD’s, courtesy of Rená at Abbadabba’s. I used the same brand paint as previous shoes and added purple tulips with green stems. I then outlined the flowers with a fine-tip permanent marker. I began by using a “very fine” tip, however the paint dried out the marker tip. I then switched to a fatter “fine” tip marker and with enough finesse, I was still able to draw very thin lines.

I decided not to dye them because I have had problems with other shoe-dying projects lately. When dying bright colors such as red and navy blue, both the canvas and the rubber changed color. Also, as I learned the hard way, it is impossible to bleach black canvas Vans white. I tried to make white shoes with black soles by starting with the black/black Vans slip ons. The fabric disintegrates very quickly and begins to rip after coming into direct contact with bleach.

Anyways, I learned a lot during this project about delicacy and patience. Its not easy to fix a mistake on white canvas. Slight smudges of purple are obvious in one of pictures below.

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2007 Santa’s Little Messenger Race

This year, like last, I decided to hold the Santa’s Little Messenger Bicycle Race benefiting Atlanta’s Toys For Tots program. The concept behind the race is that individuals and businesses around town, who were going to donate a toy to Toys For Tots, register the toy with me via a web form instead of finding a local drop off point. Then, on the day of the race, riders picked up the toys and returned them to the “base”. Two categories of racers (solo and two-person teams) competed to earn the most “toy miles”.

The race began almost immediately with a terrible rain storm but all the riders really toughed it out and did a great job. This year, seventeen racers (six teams and five solo racers) collected 96 toys. The complete results are available on Faster Mustache.org.

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Performance Testing NXT’s Ultrasonic Range Finder

I have plans to utilize the Lego NXT system for several upcoming robotics projects. The success of these projects depends on the capabilities of the kit’s ultrasonic (US) range finder. I created a test rig with the US sensor and NXT brick and conducted several experiments in order to characterize the sensor.


Test rig: wood block, measuring tape, protractor, US sensor, NXT brick (from left to right).
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SLAM-5 Bot part 1: The Hardware

I recently purchased Lego’s new NXT hobbyist robotics kit. After familiarizing myself with the basic layout of the command module, available hardware and sensors, and third-party programing languages by building several single-task robots, I decided to use the NXT as a forum for my studies in SLAM robotics. As I have previously quoted, Dr. John Leonard of MIT says,

The problem of SLAM is stated as follows: starting from an initial position, a mobile robot travels through a sequence of positions and obtains a set of sensor measurements at each position. The goal is for the mobile robot to process the sensor data to produce an estimate of its position while concurrently building a map of the environment.

My goal and new perspective on the problem is to design a system which is as simple as possible. I immediately realize that much of the complication in SLAM systems lays in the timeliness with which the system processes information in real time. I know that some compromise between speed and simplicity had to be established, and in pursuing the most simple system, I am willing to sacrifice a lot in speed. So I have created what I am calling the “slam five robot”. The real acronym is S.S.S.S.S.L.A.M. which stands for “super-simple, super-slow, simultaneous localization and mapping robot”.

The system consists of three components: the physical hardware of the robot, the control algorithm which guides the hardware and sensors, and the post processing algorithm which interprets the sensor data. I begin here by describing the hardware and sensor setup.


Front view of the SLAM-5 bot, showing ultrasonic range finder and wiring for the drive motors.

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