Reviews – Mark Foster's Blog

Review: Adafruit ARDX Experimentation Kit for Arduino

My dad got me an ARDX Experimentation Kit for Arduino for my birthday. I just finished all the 13 experiments and I have to say it is a pretty awesome kit and a good introduction to the Arduino. The kit comes with a variety of input and output components/devices including:

10x Red and 10x Green LEDs
10mm Blue LED
5mm RGB LED
Force Sensor
DC Motor
Hobby Servo
Shift Register
Piezo Element
Pushbuttons
Variable Resister/Potentiometer
Photo Resister
Temp Sensor
Relay

Also included are some transistors, resistors, diodes, etc. After you finish going through the experiments this gives you a good head start once you decide to build your own project.

Another bonus to the kit is that is comes with a custom cut piece of clear acrylic to mount the included Arduino and a bread board. There are wiring sheets you can cut out and overlay on the bread board but I didn’t find these necessary.

Code for most of the projects can be found online at the URLs mentioned in the instructions with the exception of the last two experiments. For the RGB LED experiment I could not find the code online and I had trouble with the code printed in the manual. I had to make the color arrays regular variables instead of constants to get the code to work for me. I could not find the force sensor code online either but the code printed in the manual worked and was pretty trivial to enter.

Overall I have to say this is a great kit for someone that would like to learn how to use Arduino to interface with real world devices.

The ARDX kit comes with many electronic components and breadboard wires. More than needed to complete all the experiments.

The Arduino comes packaged in an interesting little box.

A 9 volt battery clip and power plug are included so you can run your Arduino without a USB connection for power.

The manual is complete with a deion of all the components, and 13 experiments.

One experiment uses the Arduino in combo with a transistor to control a small toy/hobby motor. Code is included to shut the motor on and off and run the motor at different speeds.

Experiment 5 shows you how to use a shift register to effectively add many more digital outputs to the Arduino.

An RGB LED experiment demonstrates how to combine the base colors to create additional colors.

Experiment 13 demonstrates how to use a pressure sensor with the Arduino. The Arduino increases the brightness of an LED as more pressure is applied.

April 14, 2012

National Broadband Map Review

The National Telecommunications and Information Administration (NTIA) in collaboration with the FCC has published a series of broadband maps on a new site called National Broadband Map (NBM). These maps show what broadband services are available throughout the United States as well as other interesting broadband data.

Hit this link and click the “Explorer the Map” option on their main page to see a map of the US with shaded areas where selected broadband services are available. You can click different selections above the map to toggle the various broadband technologies. To see other maps such as advertised versus actual broadband speeds click on the “Show Gallery” option in the lower right hand corner.

Rochester, NY does pretty well on advertised versus actual although there a few slower than advertised points here and there. Upload performance data is also available. Usually the cable and DSL providers don’t brag much about upload performance likely because in most cases it is lousy compared to download performance. I think upload performance will become more important to the typical internet user than it as in the past now that people are sharing their pictures and video online.

The NBM site use a variety of open source technologies including:

JQuery – My favorite JavaScript library.
Modernizr – A JavaScript library to detect browser capabilities.
OpenLayers – Provides a JavaScript API to display WFS and WMS GIS layers.
GeoServer – A Java based server software that provides WFS and WMS services.

What is particularly interesting about the site is the developer resources. They provide a series of API’s you can call from your own web applications to use their data. Output formats include XML, JSON, and JSONP implementations. If you want to use the data locally without the APIs you can download it.

I do have a couple criticisms regarding the maps and ironically, they are bandwidth related. The first is that there are too many tiles returned when viewing the default map of the US. I noticed the map was a little slow to fill in. When I enabled Firebug and clicked on the “Explore the Map” option off the main page, over 500 tiles were pulled down. In fact, Firefox/Firebug became unresponsive. I would expect less than 30 256×256 tiles need to be pulled down for a reasonably sized browser window. I wager there is something goofy going on like a bounding box not set for the area displayed.

My second criticism is that the site is not using gzip to compress JavaScript files. Modern web applications tend to lay on the JavaScript pretty heavy and this one is no exception. OpenLayers.js is nearly 1MB all by itself. By enabling gzip on sites with large JavaScript files you can significantly improve site performance. This is a good topic for a future post.

Overall I think the National Broadband Map Site is an excellent resource. It provides very useful data on broadband technologies/speeds, makes this data available via APIs or download, and also demonstrates a variety of open source web application technologies.

Is it worth the $20 million that contractors were paid to build the map? I would say certainly not at first glance but I would want to hear the whole story before I jump to conclusions. I.e. how much of that $20 million was spent on actual development? I am much more skeptical of the alleged $293 million required to collect the data.

February 24, 2011

Review: Herbie the Mousebot Kit by Solarbotics

I wanted a quick, easy to build robot kit to get back into electronics and robotics. I ask for a Herbie the Mouse Bot for Christmas and sure enough I got one. It was a fun kit to build and went together in a little over an hour.

You start off with a PC board…

… and a handful of components…

You break apart the PC board which serves as a PC board and a body for the mouse which, is pretty cool.

The PC boards join together via several solder joints. Tape is used to keep everything together until you are done soldering. A smaller board that holds the 9 volt battery connector helps keep the three main sides together. By the time you are done soldering all the joints it is a pretty sturdy little robot.

The whiskers and tail activate a relay when bumped so the mouse will backup to avoid getting stuck. I taped the relay down while I soldered it in.

Herbie with the photo diode “eyes” installed….

Herbie just about finished…

Herbie is an interesting robot because it uses a simple analog IC, the LM386, to do something you might think requires a much more complicated digital circuit or micro-controller/processor:

http://downloads.solarbotics.net/PDF/Solarbotics_Herbie_the_Mousebot_Instruction.pdf

We don’t have much open bare floor in the house and it moves quite fast so it was a bit of a challenge to keep it under control without hitting too much:

The Herbie Kit is well engineered and fun to assemble. I give it five stars and recommend it as a good first robot kit.

March 19, 2009

Review: Weller WLC100 Soldering Station

I have started to take a renewed interest in electronics again lately and wanted to get a good soldering station to work with. I have a couple fixed wattage irons I use for my RC plane wiring but I wanted something adjustable with a variety of alternative tips available.

I ordered a Weller WLC100 and it is working pretty well for me so far. I also ordered some smaller conical and screwdriver tips that make it easier to solder smaller components and connections. One of the reasons I went with the Weller is because it is a relatively well know brand and I know I will be able to find tips for it.

There are more expensive solder stations that have digital controls and displays but I decided that an analog control was adequate. After using the station for a bit I am pretty happy with the analog control. The amount of heat transferred is so strongly dictated by the conduction of heat between the iron and the component/pad that I don’t know that such temperature precision makes much difference for most hobby uses. If you just tin the tip of your iron with a little bit of solder it will make significantly help with the transfer of heat from your iron to the component/pad you are soldering.

The Weller iron is easy to grip with my fingers and doesn’t get too hot to handle at all. I built a Herbie the Mousebot Kit with it using a .062″ screw driver tip. It was nice to work with and did the job well. I would definitely pick up some smaller tips if you are going to be soldering smaller circuit boards. The screwdriver tip that comes with it is pretty nice but a small tip affords more precision.

I give the Weller WLC100 5 out of 5 stars. It is a good, relatively cheap soldering station with many tips available. Buy one and a couple tips to go with it:

Conical Tip, .031

Narrow SD Tip, .062

February 21, 2009

Review: Lego 6211 Star Wars Imperial Star Destroyer

Jen gave me the Lego 6211 Star Wars Imperial Star Destroyer for Christmas and I finished building it over the following week.

The build is pretty easy (even for a 35 year old) and a lot fun. The kit comes in over 1300 parts so you really feel like your building something and not just putting a couple halves together. The parts come in numbered bags that correspond to the numbered sections in the instructions. There are often multiple bags with the same number for a single section. Lego included a few extras of the tiniest parts that tend to get lost in the carpet.

There are only a couple downsides to the kit. The two “laser blasters” that launch projectiles work by you just quickly depressing the launch button that drives a wedge piece behind the projectile to push it out. This is kind of silly to me and I think the kit would have been better if they were just static elements in my opinion.

The other negative was the capsule that goes inside. It is assembled by connecting two specially molded pieces together. I don’t like this kind of Lego construction and would have preferred it if they just left it out or designed it to build from smaller, standard Lego pieces.

I put together a list of pros and cons:

Pros

Over 1300 parts so it will keep you building for a bit.
Numbered bags.
Spare tiny pieces.
Looks great!
It’s big. About 23 inches long.

Cons

The laser blasters that shoot projectiles are kind of cheesy.
The capsule that goes inside is mostly just two halves that go together.
Doesn’t shoot real bolts of green light. 😉

Build gallery

I took some pictures while my Imperial Star Destroyer was under construction:

Embellishment

I felt the kit would have been better if they included lights and a small universe. Fortunately, I was able to accomplish this with a small string of Christmas lights, a telescope photo of the stars, black velvet, and a little Photoshop magic: