Mark Foster's Blog

Category: Electronics

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
TreeBot

For Christmas 2011 Pictometry had a holiday “Throwdown” challenge. Each department was given box of miscellaneous items that had to be incorporated into some sort of creation. The box was handed off from one engineer to the next. Everyone was too busy. Finally, with two days left before the judging, it was time to take action. With much help from my fellow engineers I built TreeBot, a remote control Christmas Tree with all the trimmings and wireless video for remote operation.

It consists of my old Duratrax Evader RC car with a Christmas Tree mounted to it, Christmas lights on a power inverter, an iPod Shuffle playing Christmas tunes on an amplified speaker and a 2.4 Ghz video transmitter for remote operation. It is decorated with various items we had to use in our creation. We came in second place behind Finance who did a Christmas Carol play using the items as props but I feel it was a good entry representative of engineering given the time constraints.

I took some pictures of TreeBot as I took it apart in case we decide to build something similar next year:

TreeBot

We used a cheap amplified speaker and an iPod Shuffle loaded with Christmas music to give TreeBot a voice.

A 2.4 Ghz video transmitter was used to transmit TreeBot’s perspective to a receiver wired to an old analog video monitor another engineer donated to the cause.

If I were to do it again I would use a wider angle lens for the video camera. Navigating around corners was particularly difficult because of the narrow field of view.

We made the face out of materials provided. The eyes are made from little sticky foam beads shaped into balls and the mouth is a strand of foam peanuts.

TreeBot was lit up using a standard strand of incandescent Christmas lights (provided) using a cheap power inverter on a 3000mAh 3S LiPo Battery pack.

Presents were secured to the tree using zip ties. Nylon zip ties were used extensively throughout TreeBot.

A piece of wood was placed into each of suspension points to keep the car from sitting on the ground under the weight of the Christmas Tree.

The skirt of TreeBot consisted of two pieces of cardboard from the box we were given cut into two half circles and then stapled together to form a semi-cone. It was covered with wrapping paper and garland was zip tied around the edge. The skirt was then zip tied to the Christmas Tree stand.

The stand that came with the Christmas Tree was zip tied to the car’s frame.

Bolt’s were used as a standoff to level the Christmas Tree stand on the car. Zip ties were again employed to secure the Christmas Tree stand to the bolt heads.

It was not terribly shocking to find that the cheap power inverter wasn’t putting out the advertised voltage even though our input voltage met specifications. Regardless, it was enough to power a strand of Christmas lights.

This is the car frame after everything was removed.

The car has been returned to its former self.

April 1, 2012
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