MICROCONTROLLERS: my introduction 100509

I have been wanting to build lots of things: an automated cat feeder, a watering system, a computer-turn-er-on-er, and various art stuff.  These things all require some knowledge of microcontrollers.  Which I don’t have. So, I’ve been paying attention to a local group, Open Tech Space, and saw that they were having two workshops: microswitches and the Arduino Cult Induction.   Both being hosted by my darling, Portland TechShop (great deals on memberships right now!!).    ** Disclaimer! All my “nube knowledge” is what I learned, as it filtered through my brain which is heavily influenced by my education in speech language pathology – I can tell you the spectrograph characteristics of most of the phonemes of the english language – which is a little skewed from your normal technogeek nomenclature.  So, what I’m getting at is: I could be wrong!!

I took the microcontroller class on the 5th, taught primarily by Paul Stoffregen, using his “Teensy” microcontroller – a very cute little thing.  The first thing I learned was that there are lots of different microcontrollers out there!  – See how nube I am? –  Each has different strengths and weaknesses, so you pick depending on your project.  For example, someone told me you can get a Teensy with WiFi already on it! Very cool!  So, in this class we plugged our little Teensy into a breadboard (nube knowledge: a breadboard is a place to easily plug your chips and accessories in without soldering, so you can pull them out and rearrange them easily until they work) and attached many microswitches.  We used several microswitches in this class:


The first thing we put in was an RGB LED.  We first wrote code (in C – something I’ve NEVER done before!) to make the light flash red.  Then we started getting trixy by making it flick from red to green to blue, and THEN we started having it slowly transition by increments from red to green!  Finally we worked to make different colors like purple and yellow – all by changing the intensity and frequency of the variables! Very fun!  When we put in the LED we chose three pins with the “PWM” feature (nube knowledge: PWM stands for “Pulse Width Modulation” and refers to that part of the chip being able to control the duration and frequency of the electrical signal to the device. This is how you can carefully control the amount of light being emitted to change its colors).  We began to explore output as well, using “Digital Output” (nube knowledge: “digital” most of the time means on/off, or yes/no, or as in this case high/low – so when when it says “high” a relatively larger amount of current is allowed through the bulb, when it says “low” only a little bit of current is allowed. I think.) and “Analog (PWM) Output” (nube knowledge: “analog” in this case refers to the fact that you can have a variety of values, not just two. So we actually use numbers between 0 and 255 (I’m not sure why) to refer to more variable levels of current through the bulb where 0 = “low” and 255 = “high”, but now we can represent any amount of intensity between them.)

Ok, I have to stop for now, but will pick this up again soon and cover the other microswitches we learned about – this is a really great way for me to remember what I learned.  Overall, this was an awesome class! Paul was a great instructor: clear instructions, good pacing for the nubbies, nice overhead projector support and an EXCELLENT written handout that I was able to follow several times on my own.


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