Michael Hamilton has been designing microcontroller-based systems for 25 years. Over the past 10 years, he has spearheaded two companies: A&D Technologies, which supplies wireless temperature and humidity controllers, and Point & Track, which provides data-gathering apps and other business intelligence tools. In January, I interviewed Michael about his longtime interest in electronics, his first microcontroller design, his award-winning Renesas Electronics RL78 project, and his praise for 3-D printers.—Nan Price, Associate Editor
NAN: Where are you located?
MICHAEL: Lewisville, TX.
NAN: Give us some background information. Did anything specific spark your interest in engineering?
MICHAEL: My dad was an instrument repairman for Ashland Refinery in Canton, OH. As part of his training, he brought home his electronics trainer along with the instruction manuals.
When I was 13, I was interested in explosives and I needed an electronic timer for safety reasons. I studied his coursework and figured out how to build a timer using the famous 555 timer chip.
My family had a Christmas tree farm, where I spent many hours working. This led me to the decision that I needed to go to college instead of doing hard labor. I ended up going to Ohio University in Athens, OH, to study chemical engineering.
The reason I chose chemical engineering was, during high school I entered the science fair with a project called the “Distillation of Crude Oil.” This project was very successful as I made it to the state science fair and won lots of prizes.
After I graduated from college, my interest turned back to electrical engineering and I started reading every book I could find on electronics. I remember my first big electronics purchase was a Tektronix 485 oscilloscope.
While working for Ashland Chemical in clean room environments, I realized there was a need for an accurate humidity controller. This led me to design my own temperature and humidity controller and form my first company, A&D Technologies (www.a-dtechnologies.com) in 2003.
NAN: What types of products and services does your company provide?
MICHAEL: A&D Technologies supplies wireless temperature and humidity controllers (e.g., HTC100) along with custom control panels. Using the latest technology, the control panels communicate to the outside world using SMS texting via cellular modems and e-mail via Ethernet.
Along with another partner, we created a new company, Point & Track (www.pointandtrack.com), which provides custom data-gathering apps for mobile devices such as iPhone and Android, secure database management, and business intelligence tools used to analyze collected data. The company also provides the ability to export geographic information system (GIS) data directly to customer-owned databases.
NAN: What type of work did you do prior to A&D Technologies and Point & Track?
MICHAEL: I was a project engineer who designed and installed automated equipment such as a fully automatic coiling systems using an ABB robot.
NAN: How long have you been designing microcontroller-based systems?
MICHAEL: Twenty-five years.
NAN: What was the first microcontroller you worked with?
MICHAEL: It was Microchip Technology’s PIC18F84. I designed a laser viscometer that was used to determine the viscosity of plastic resins while working for Ashland Chemical in Los Angeles, CA. I learned how easy it was to provide precise timing and work with digital I/O. It was so much easier than trying to work with individual integrated circuit (IC) chips.
NAN: What is the worst problem you have encountered with embedded microcontrollers?
MICHAEL: By far, the worst issue has to do with electromagnetic interference (EMI) from nearby devices, such as switching of solenoids or transformers. An extensive amount of time is spent designing PCBs so they will be immune to the external environment. Things like ground planes, metal oxide varistor (MOVs), transient voltage suppressors (TVSes), and capacitor/resistor networks are used to minimize the susceptibility of the microcontrollers, but it seems like you can never predict the environment for these kinds of issues. Maybe someone will write an article discussing these issues and how to prevent them.
NAN: Any recent tech purchases?
MICHAEL: I recently purchased a Rigol Technologies DSA-815-TG spectrum analyzer. This device is a must have, right behind the oscilloscope. It enables you to see all the noise/interference present in a PCB design and also test it for EMI issues.
NAN: Do you have any other unique tools on your workbench?
MICHAEL: I have a three-axis CNC machine and a MakerBot 3-D printer. I use the CNC machine to cut out enclosures and the 3-D printer to create bezels for LCDs and also to create 3-D prototypes. These machines are extremely useful if you need to make any precise cuts or if you want to create 3-D models of future products.
NAN: What is the fastest way to learn about programming and electronics?
NAN: Your project, the Cloud Electrofusion Machine, recently won second prize in the 2012 RL78 Green Energy Challenge. Tell us about your project and your contest-entry process.
MICHAEL: The project created an in-expensive and energy-efficient way to weld polyethylene pipe together. Commercial machines cost around $4,000. This machine can be built for less than $200. It utilizes a light dimmer to drop the voltage from 110 to 40 VAC and controls the amount of time that the power is applied to a coil inside an electrofusion fitting. By incorporating a barcode scanner, all the specific properties of the fitting can be easily entered into the microcontroller. Then, after the fusion is complete, all the data is sent to a cloud server via a wireless cellular modem.
The RL78 was very easy to use and program. I really didn’t have many problems with the design.
NAN: Your article “Infrared Radiation Measurement: FFT Double-Beam Infrared Spectrophotometer” (Circuit Cellar 229, 2009) describes a spectrophotometer built around a Microchip Technology dsPIC30F4012 digital signal controller. How does the microcontroller work in the design?
MICHAEL: The project created an instrument to identify chemical substances by using infrared spectroscopy. The dsPIC30F4012 uses a 10-bit ADC to measure the infrared radiation signal that passes through a chemical substance. Then the microcontroller computes the fast Fourier transform (FFT) of the signal. This creates a table of amplitude versus frequency. The amplitude is then scaled to provide a relative transmittance. This information is serially transmitted over USB to a computer for plotting. This USB interface is accomplished using a PIC18F2450.
NAN: Are you currently working on or planning any microprocessor-based projects?
MICHAEL: We are currently working on a cloud fusion logger. This device reads all the data from the welding process in the field and transmits it to a cloud server. Later, the data can be analyzed and reports can be generated. A Raspberry Pi is used as the embedded controller. It is very fast and easy to use since it is based on Linux. We are working on getting the Android operating system loaded so existing code can be used and it will interface well with an Android smartphone, which will be used as the operator interface.
NAN: What do you consider to be the “next big thing” in the embedded design industry?
MICHAEL: One of the issues with embedded controllers is how to maintain the firmware and fix bugs after the devices are installed in the field. Using various wireless technologies, the devices will be automatically updated. Smartphones already use this technology.
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