First Meeting of Humboldt Microcontrollers Group

So I figured the first meeting of the Humboldt Microcontrollers Group (which was tonight, May 15, 2014) would be a pretty quiet one, likely just Nick and me, maybe one or two others.

It turned out that instead of two or three people, we ended up with nine people participating in the kick-off meeting for the group! If we have nine people, or more, show up at the biweekly meetings (next one is May 29, put it on your calendar), well have to figure out a bigger meeting area. But having lots of people show up is a good problem...

Tonights meeting was mostly a meet-and-greet, finding out what each persons experience with electronics was (if any) and what will make it worthwhile for them to participate in some, most or all of the groups future meetings. The interests ranged from just learning about microcontrollers and how to make one do simple things, all the way up to making a tracking mechanism for a radio telescope.

For the May 29 meeting, the current plan is to start out with a short discussion and demo on one of the topics covered in the 4th Jeremy Blum Arduino video tutorial. We wont repeat what is done in the video, but Nick will pick one topic from the video, and hell go a little more in-depth about that, or show and explain some aspect of the topic that Jeremy didnt include in the video.

After Nick does a short show and tell, well split up into a learner group and an advanced group. The learner group will discuss the topics and exercises in the 4th video, and make sure all the learners are up to speed on that, then go back over anything in the first three videos that people might not have had a chance to ask questions about tonight. Nick will facilitate the advanced group in working on a project or designing a future project, or hell come up with some other way to get the advanced microcontroller people learning, teaching or just having fun making something with microcontrollers.

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Blum 6 Arduino Video Tutorial Humboldt Microcontrollers Group Meeting

Tonights post is a quick look at the #6 Arduino video tutorial from Jeremy Blum, which is the main topic for the Humboldt Microcontrollers Group meeting this Thursday, June 26.

The #6 video tutorial, Serial and Processing takes a look at how to use an Arduino for communicating with the computer via a serial connection and using a programming language called Processing to visualize information from an Arduino on your computer screen.

For the serial communication between the Arduino Uno and the computer, the 0 RX (receive) pin and the 1 TX (transmit) pin on the Arduino are used. You connect the Arduino to your computer via a USB cable, which has 4 pins in it. One is power and one is ground. The other two are the serial transmit and receive pins. The USB transmit pin from the computer connects with the receive (RX) pin on the Arduino, and the computers USB receive pin connects to the Arduino transmit (TX) pin.

Jeremy runs through a number of Arduino programming examples for learning how to use the serial communication features. If you go through the #6 Blum video and feel you still want a little more background on serial communication with Arduinos, here are three other resources to look at:

1. The Arduino.cc reference page for serial communications
2. An Arduino tutorial from Ladyada about serial communications
3. A guide from Instructables on Serial Communications with Arduino

After he does the serial communications exercises, Jeremy covers a little bit about the programming language Processing. You start out by going to the website for Processing. The home webpage for Processing says its an open source language that:

"has promoted software literacy within the visual arts and visual literacy within technology. Initially created to serve as a software sketchbook and to teach computer programming fundamentals within a visual context, Processing evolved into a development tool for professionals...there are tens of thousands of students, artists, designers, researchers, and hobbyists who use Processing for learning, prototyping, and production."

In addition to the presentation and exercises with Processing that Jeremy Blum has for you in the video, if you want a better understanding of the language, you can spend some time going through some of the tutorials on the Processing website. If those tutorials arent your cup of tea, take a look at these resources for learning the basics of Processing:

1. The intro page from Arduino.cc for the Processing language
2. A SparkFun intro called "Connecting Arduino to Processing"
3. An Instructables session on "How to control LEDs with Processing and Arduino"

Mark your calendar for this Thursday, and plan to be at 1385 8th Street, Arcata, California, from 6 to 8 PM for the Humboldt Microcontrollers Group meeting!

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Humboldt Microcontrollers Group June 12 Meeting Notes

Getting started on this post much later than usual, so it will be just a few comments about what happened at tonights meeting of the Humboldt Microcontrollers Group.

Due to people being out of town and having prior commitments, there were only four participants in tonights meeting. We still had good discussions about microcontrollers and electronics, and I, at least, learned a few things about controlling motors with microcontrollers (MCUs).

TI Tiva C LaunchPad board

Ed started out the night by showing us the powerful $20 Texas Instruments (TI) Tiva C LaunchPad board he received recently from TI. He hasnt a chance to hook up any fancy demonstrations with it for the group yet, but he did seem pretty happy with it. Well likely have a blog post about it from him in the next few weeks after hes had a chance to work with it.

Ed also brought his less expensive TI LaunchPad board which he is using for some capsense proximity sensing. He talked about that at the previous Humboldt Microcontrollers Group meeting, and brought the small LaunchPad to demonstrate some capsense work hed done since that previous meeting.

The third item Ed brought were some nice oscilloscope screenshots of the PWM (pulse width modulation) control of the DC motor, since part of tonights meeting was planned to be discussion of Jeremy Blums Arduino Basics #5 video tutorial about motors and transistors. Youll see those oscilloscope screenshots in an upcoming blog post. Ed explained what the screenshots showed and the difference between the various trace patterns.

Nick explains how the chicken coop door opener will work.

Nick brought the work-in-progress door opening mechanism for his new chicken coop. Im trying to talk him into writing one or several blog posts about the project, but so far his time has been focused on finishing the design and getting it built. He powered the circuitry for opening and closing the door and showed us how it works. One of the door automation components is a part off an old Willys Jeep, which makes his chicken coop door more interesting and a bit unique. Its unlikely many other chicken coop doors in the USA have parts from a Willys Jeep. We just hope the chickens appreciate the history and character of their coop door!

After Nick demoed the chicken door opener, he talked briefly about the microcontroller educational kit he received from TI. Were looking forward to him bringing that to an upcoming meeting and maybe writing a blog post about the kit.

First circuit in #5 video tutorial

Next we spent some time talking about microcontrollers and motors, with the discussions being primarily to help me understand how circuits should be designed for controlling motors with an MCU and how the components for the circuits should be selected or sized. After we got most of my no load current, voltage operating range, stall current and collector current questions answered about motors and transistors, the group helped me finish breadboarding the first exercise in the #5 video, Nick typed up the sketch for the Arduino to operate the motor, we plugged it into power -- and the setup worked perfectly. Voila!

This weekend, Ill go through that exercise again by myself to make sure I understand it, polish up the code in the sketch a bit so it has comments in it and so I understand what each part of the code is doing. Then Im hoping to work on the rest of the #5 video (although I still need to work on a couple previous videos in the series...).

One last thing discussed was the Humboldt Microcontrollers Group wiki. We started out with a Wikispaces wiki, but have decided to move away from that wiki service because they require everyone who wants to view their wikis to sign up for an account. Thats just annoying for how we want to use the microcontroller wiki. So Ed is hosting a MediaWiki site, and we hope to have that operational in the next week or two. Well put a link to the wiki on this blog once the site is up and running.

See you in two weeks (thats Thursday, June 26) for the next Humboldt Microcontrollers Group meeting.

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May 29 Second Meeting of Humboldt Microcontrollers Group

Short post tonight -- just got home from the second meeting of the Humboldt Microcontrollers Group because it ran long. Which is a good thing, since people wouldnt have hung around past the nominal 8 PM meeting end time unless they were enjoying themselves.

We only had four people for most of tonights meeting, which is about half the size of the first meeting. We hope the low participation in tonights gathering was because the other people from the first meeting just couldnt make it to tonights meeting but are still interested and will be at future meetings.

About 2/3 of the way through the meeting, another person joined the group. He first had to find
someone to let him in the building because the doors to the Greenway Building were all locked. The front door had been propped open with a wooden wedge and the meeting information posted on the laminated sign on the front door saying to keep it open until 8 PM. Unfortunately either someone accidentally kicked the wedge out of the way or closed the door on purpose before 8 PM, because a couple people were unable to join the meeting because the door was locked.

I apologize to anyone who attempted to come to the meeting tonight and was locked out. To address the issue of the front door being automatically locked after 5:30 PM, for the next meeting (on June 12) we will:

1. Put the wedge in the door to hold it open and write the meeting info on the laminated sign.
2. Check on the door at 6:30 and 7:00 PM to make sure its still open.
3. Put a Humboldt Microcontrollers Group meeting sign on the front door with a phone number of someone in the meeting to call if the door is locked.

We also might meet down in the front lobby area at the big round table. That way we can see the front door and know if it gets closed during the meeting.

We talked about a wide range of subjects in tonights meeting, but the two primary microcontroller topics were CapSense and IR sensors for motion detectors. Ill write more about those two tomorrow -- too late tonight for technical topics.

For the June 12 meeting of the group, well be focusing on the #5 Blum video tutorial, which covers motors and transistors. If there are people new to microcontrollers at the meeting, a group will split off into a separate area to talk about the first Jeremy Blum Basics of Arduino videos. The more experienced people will cover breadboarding or other work they did on the topic of motors and transistors, as well as any specific exercises or questions they had from the #5 video.

Hope to see lots more people at the June 12 meeting, including anyone who was inadvertently locked out tonight...

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