General I/O

Awesome Mini Rover Robots

2011-08-21T01:32:00.000-04:00

I can't lie I was pretty excited to see the preview video for this new mini packbot by iRobot. I had seen some renderings more than a year ago and thought it would be a really cool little bot. So after seeing this the other day I searched out for small tracked rover platforms.

I had remembered seeing a tracked rover at SparkFun so I looked there first. Sure enough they have the Rover 5 robot platform. It is 4 wheel drive tracked rover with independent encodors on each wheel. The platform is made by Dagu and can bee found at many hobby robot retailers.

I checked out Pololu and RobotShop which were also selling the DFRobot RP5 which has two motors and costs less than the Dagu chassis.

Since the two products above are simply chassis with motors there are some more complete kits available. I found one in particular from RobotShop that was a pretty near complete robot called the DFRobotShop. It is a tracked robot with a chassis that is a lot like a Tamiya kit that has been very popular with beginning robot builders. On top of a chassis and motors it's body also includes an Arduino compatible microcontroller, a built in motor controller chip and a battery holder that powers everything. Also it has cool blue LEDs!

I'm not sure that any of these platforms can satisfy my desire to have my own personal attack robot that can survive being thrown through plate glass windows and fall down flights of stairs on purpose but they all look like fun starting points.

Also checkout Cellbots. They make software that lets your android phone be the brains of your robot over a bluetooth serial connection.

Links:
http://www.sparkfun.com/products/10336
http://www.robotshop.com/dfrobot-mobile-tank-base-1.html
http://www.robotshop.com/dfrobotshop-rover-tracked-robot-basic-kit.html

Microcomputers!!

2011-06-08T09:41:00.078-04:00

So every now and then I get really obsessive over something and within months to a year I notice that my interest is getting some attention from other people too. Now I don't know if this is some sort of collective consciousness syndrome or what but it's kind of cool. The latest such interest:

Microcomputers!

More specifically I've gotten interested in what modern replicas are out there. Because the microcomputers I was interested we're some of the first microcomputers and are collectors items they are too expensive to purchase just because you have a passing interest. The first thought is that you can just run emulators of them and I did do that but what's much more fun is a physical device that you can turn on connected to an old monitor and type into.

The first one I got interested in was the Apple I. There are two replicas that are available.

A-One

Replica 1

I looked at an Altair 8800 clone Altair 8800micro. I programed an Altair 8800 at MakerFaire it was a really cool experience.

Also at MakerFaire was the Digi-Comp II by Evil Mad Science Laboratories.

This weekend I noticed an Instructables blogged about by Ian at Dangerous Prototypes. It is Jeff Ledger's retro style microcomputer project using all off the shelf components. It is based on a propeller development kit that you can purchase for $80.

Will we start seeing more and more retro computing projects becoming trendy? With the abundance of powerful and inexpensive electronics and a generation that missed out on a whole period of computer history I think we might.

Links

Briel Computers

The Vintage Computer

Welcome to the Service...

2010-03-09T00:56:00.000-05:00

The words said by a burly lumberjack of a man as he shakes my hand. In middle school I took a few courses in the evenings with quite similar looking men both teaching and attending, not a single person there within 20 years of my own age. The courses were preperation for the amateur radio operators exam. Attending the courses ended short after a rash of rebellious boyhood behavior on my part and the subsequent groundings for eternity.

A few weekends ago it struck me that I've been working with RF for three years now professionally and I know all the respective lingo. dB's and MHz, ohms and Watts fit me like a $10 Snuggie. One thing that helped me realize this was seeing some of Diana Eng's excellent posts on Make Blog.

So the first stop the was the American Radio Relay League. I found out that there are now three levels of Amateur Radio Licenses. Technician, General and Extra. I found out when and where local exams were being held with the help of the ARRL Exam Session Search.

There are a few different avenues you can take when studying for the exams. There are books published by the ARRL in both full textbook style form and also books with just the questions and answers to the exams. There are many places online where you can practice the test on a web page which will score your test and tell you if you've passed or failed along with the right answers to the questions. The best way I found to study was by listening to the Ham Radio Podclass. These cover all the the material through the Technician and General licences. I practiced for my exam by using some great iPhone apps by Patrick J Maloney. These were well worth the money, they are slick to use and tracked my progress while I practiced.

After about a week I went and took my Technician exam and passed. It cost me about $15 dollars and all I needed to bring was a photo ID. If you pass the first test you take you can go onto the next test for free. This is always worth a shot. I didn't pass the next test unfortunately but after some studying I went back a few weeks later and passed the General exam.

Picking some hardware to communicate with was the next task at hand. I was mainly looking to operate on the VHF/UHF bands which let you communicate locally either directly between two hams or via a repeater which lets you talk over a much wider area. I compared the merits of both mobile radios and handheld transceivers.

Mobile radios are primarily for installing into a vehicle and need a connection to the battery and an external antenna.
Handheld transceivers are usually rechargeable and have a "rubber duck" style antenna attached.

I am lucky enough to have a Ham Radio Outlet location close by so I was able to head up there and play with some different radios and ask questions. I decided on a handheld radio so that I could operate untethered even though I would be giving up some power output. I picked out the Yaesu VX-7R. One thing I suggest doing is visiting eHam.net where you can read tons of reviews on any kind of ham equipment you can think of. When I was narrowing down my options I liked to sort their review sections by number of reviews. This helped me see what were the go-to brands and models that have good reputations.

After a week of operating mainly in my car I started to see the benefits of an external antenna so I picked up a dualband magnet mount Diamond MR77SMA. It goes right on my roof, I run it in through the trunk and it has an SMA connector that fits my handheld. This greatly increased my range for both receive and transmit.

Really the primary article that got me started down this path was Diana's Catching satellites on ham radio. Satellites were always a big draw when I was looking at the hobby when I was younger so seeing just how accessible it was to operate this mode was really exciting. WA5VJB has put together a great walk through(pdf) on making an inexpensive yagi antenna for satellite communication. I picked up some materials for less than $20 and got started on it. I need to make some adjustments and I hope to have more information about the build posted soon.

The last thing I want to talk about is software defined radio. This is the really exciting stuff! In short you take some simple (or not so simple) RF electronics and make what is in the air readable digitally. This can be done with a sound card or fancy Analog-to-Digital converters and other digital electronics. Then your able to do all sorts of things with the data. You can decode FM signals or extract image information from weather satellites. Here is a basic kind of software defined radio that is really inexpensive and can do some powerful stuff called softrock. For something really tangible you can check out WebSDR is has links to software defined radios all over the world that are receiving real signals. The data is pumped to your web browser and you can tune around the bands in real time, adjusting the bandwidths and filters. This isn't your Daddy's shoutcast stream.

Photo

Format Change

2009-11-30T20:57:00.003-05:00

One of the reasons I don't write blog entries as often as I would like is that I have a particular type of personality. One that chooses it's own fixations whenever it pleases. I live a life of periodic obsessions some for weeks some for months. When I started this blog I was in the middle of one of these periods. It happened to be based around electronics and the Arduino platform. Since then I have been overcome with some technical and some non-technical interests and didn't see this as the medium to express them. I'm going to make an attempt to document these periods that I go through technical or not. It just so happens that right now my interest is very technical so I'll be taking some time to write up where it has taken me so far.

Stay Tuned...

Arduino MEGA

2009-03-16T21:00:00.005-04:00

I'm very excited about this first shot of the new Arduino MEGA. It is built around an ATMEGA1280 and looks like it has some pretty hefty specs. It has a completely new I/O layout so it does not look like it will be compatible with existing Arduino shields made for the Diecimila or Duemilanove. This is good news for any of us craving more digital, analog and PWM pins. No word on release date or pricing just yet.

128KB of Flash
4KB RAM
4KB EEPROM
53 IO
4 HW UARTs
14 PWMs
I2C bus
16 Analog Input pins

[via]

Arduino Powered LED Roses

2009-02-13T00:30:00.021-05:00

I completed my Valentines day gift and thought I would share. Mariessa had an idea about the gift she wanted "LED Flowers" were the request. Simple on off powered LED Flowers just wouldn't do for me however. So I put together a vase with 6 flowers inside that each have a Pink LED that is connected to an Arduino. It has a button that allows you to put it into a few different modes: off, on, pwm cycling, and a special twinkle mode. It also has an AC Adapter connected for convince.

Hardware:

RBBB by Paul Badger @ Modern Device Company
6 Pink 10mm LEDs from Evil Mad Scientist Laboratories
Mini Push Button Switch from SparkFun Electronics
7 100Omh Resistors
1 10K Resistor
28 AWG ribbon cable wire
AC Adapter

Software:
To write the script I started out with the blink script and added my various modes. I ported the twinkle effect from the Valentine's Day LED Heart from NerdKits and I got the button state code from ladyada's Arduino Tutorial Lesson 5. The code is by no means polished and there are even some modes that I didn't end up using.

Roses.pde can be found under Roses in my arduino git repository on github

RGB Luxeon Lights Up and Running

2009-01-14T00:19:00.005-05:00

All three Luxeon I LED's running and under Arduino control. These things are beasts I tell you!

Hardware

It's taken me a while to get around to building this electrical prototype but it seems to be working like a charm. Right now there are three separate National Semi driver boards powered from 9V with dimming wires connected to the Arduino for PWM. I have wide angle lenses and holders on each Luxeon Star that make each to a 20 degree beam which also let me look at them without burning out my eyes. My goal is to get these into a neat package that can be used as either an Arduino shield or standalone device with an AVR built in.

Software

I have been writing a few different pieces of software that let you control the LED's over serial. The first is a Visual C# application that has direct control (sliders for each color) and a background thread that lets you check various information sources over the web and use the light as a lo-fi information display. Some examples are checking for new email and checking for local weather information. The app uses custom firmware to communicate over serial.

The second is a Processing sketch that allows control via the iPhone using TouchOSC and the Open Sound Control protocol. This sketch uses Firmata firmware on the Arduino.

I have further plans for the software that I won't get into here but it will be just as big a part of this project as the hardware.

Below is a small video of each color being testing.

*not sure yet why green wont turn off completely

The Illuminato

2009-01-12T13:58:00.008-05:00

Matt over at Liquidware has released a wonderful looking Arduino compatible board called the Illuminato. It is based around an Atmega645, has 42 I/O pins, and has twice the code space. I really like the artistic approach to the board design. All the parts are laid out on a 45 degree angle and are symmetrical. This board from start to finish is a piece of artwork. Great work!The board also has some bright white SMT LED's on the bottom of the board to give it some atmospheric under glow.

Introducing the Illuminato

$29.99 at Liquidware
Buy

Multi-Colored Arduino's

2008-12-16T12:24:00.006-05:00

There might not be anything I want more in this world at this very moment then 10 multi-colored Arduino's under my Christmas tree. I have a feeling I'm one out of not to many who would feel the same. Smart Projects has made a limited run of these colored Arduino Duemilanoves for the holidays in red, purple, orange, yellow, black, green, white, and the standard blue.

220 EUR or $302.50 from Smart Projects
Buy

[via] Arduino:Blog

Funnel IO

2008-12-13T23:08:00.008-05:00

Funnel IO is a new board that is being sold through Sparkfun. This board has some pretty promising features including an XBee socket and a Lithium Polymer battery charging circuit. The board is set up so that you can program it wirelessly through the Xbee's serial connection to the AVR. It is designed to be used with the Funnel toolkit which allows you to interface to physical components such as sensors and switches with programming languages such as Actionscript 3, Processing, and Ruby.

Another alternative for a single board Arduino/XBee is John Luciani's ZB1.

$24.95 from Sparkfun Electronics
Buy (Currently out of stock but is available on back order.)

Luxeon I Driver and Dimming

2008-11-21T22:47:00.007-05:00

I've been working on getting a driver for a Philips Lumileds Luxeon I high powered LED up and running. I tried a few designs with no success before using National's LM3404. I came across a really nice Evaluation Board that was just a bare PCB so I could pick and choose the parts I needed for my specific application and it was only $13 as opposed to the $40 it costs for the full Evaluation Board. I built up the driver board and connected it to an Arduino and used the Dimmer example sketch to PWM the driver's DIM input. This is part of a larger project I have been working on for a high power RGB computer controlled lighting fixture.

BlinkM MaxM

2008-11-18T00:49:00.002-05:00

BlinkM MaxM is a higher power version of ThingM's BlinkM. It comes in a two part form factor a top card with emitters (apparently 15 individual LED cores worth) and a bottom card for power and control. It has the same I2C connections for digital control as the BlinkM and also includes analog inputs that switches or pots can be connected to for standalone control.

I have really enjoying using the BlinkM for various applications and look forward to using this bigger brother.

Datasheet

$24.95 from Sparkfun Electronics
Buy

Intro

2008-07-17T01:19:00.000-04:00

Hi All! Thanks for visiting General I/O. My name is Christian I have been an electronics hobbyist for many years. My interests cover a range of topics including electronic projects and the design process, open source hardware and a host of other technical areas. I'll be using this blog as a place to keep people updated on projects that I'm working on. I'm also hoping to post information on different parts, tools, or technologies that I am learning or making use of.