Project

A yogurt controller.About a year ago, a friend mentioned how she made yogurt in a Crock-Pot slow cooker. It sounded impressive, and a good way to save on the cost of yogurt. We also figured that we could customize our yogurt recipe and eventually make something that would rival the taste of store-bought yogurt.

After researching a number of ways to make yogurt in a slow cooker, it all essentially came down to heating some milk up to about ~180 degrees fahrenheit, then cooling it down and holding it at approximately 110 degrees for six to eight hours. Since I have some experience working with Arduino microcontrollers, I figured this was a natural project to take to the next level. I also had some experience with PID control theory, so I knew I could write some software that would control a slow cooker and hit a desired set point with minimal error. Continue Reading

Gripper for a robotic arm.

The motivating factor for the construction of this robotic arm originally came from a tour of the Volvo factory in Göteborg, Sweden. It was during this factory tour that I first saw the massive robotic arms used to pick up car parts and weld them on to the car body. With sparks flying, these were some of the most impressive robots I had ever seen, and if you ever have a chance, take the tour!

Fast forward one month, and I was the proud owner of my first robotic arm kit, a Lynxmotion AL-5D, with the heavy-duty wrist rotate mechanism. Oh boy did I have big plans for this arm! Having some previous experience with Arduino boards, I immediately connected an Arduino Uno to the SSC-32 servo controller that came with the arm. With a little bit of web searching, I was able to find instructions and sample code which had me sending basic commands to each servo. It took another couple of weeks, but I had finally gotten the arm to move the way I wanted. Continue Reading

A completed Yagi antenna.Every once in a while, we happen to lose something around the Rusty Nail Workshop. In most cases, if we wait a while, it will simply turn up again without us having to look very hard. Unfortunately, that isn’t always the case, and sometimes a better solution is needed.

For example, we are interested in high powered model rocketry. Along with these rockets come very big and powerful rocket engines. Engines powerful enough to cause our rockets to soar to great heights. Naturally, with even the slightest breeze blowing, the rockets tend to drift on the way down and can often travel large distances over land (a mile or two). If there happens to be a forest or corn field in the rocket’s landing area, finding the rocket can be a very big challenge. This is a problem when some of the rockets start to cost a lot of money and when you’ve invested a lot of time in their paint jobs. Continue Reading

A sign using a Cholesteric LCDAfter using the Arduino microprocessor board for the past year or so, there are often projects that pop into my head unexpectedly that would be perfect for the Arduino. One such project was a desire to display the number of e-mail messages I had received on some type of electronic sign, which happened to be away from my computer. Thus, I needed a wireless way to display information.

It was about this time that I found the Google Radish project. For those that do not know, the Google Radish project was an attempt to display calendar data on conference room doors. The display updated automatically, and used solar power with a wireless connection back to a computer to pull the data. I figured I could replicate this in a slightly modified form with an Arduino. Continue Reading

The functional display.While working on a project where I needed to display some data, I came across a cholesteric liquid crystal display (ChLCD) from Kent Displays, sold by SparkFun Electronics (LCD-09560, 240 x 160). The unique aspect about this display is that the image is persistent, meaning it has the ability to retain the image on the screen even when the display is no longer powered. This means the device can save power by shutting down the display until the next time an update is needed. The down side is that the display’s refresh time is on the order of two to three seconds. Therefore, it is not suitable for animated graphics, just static images.

240x160 Graphic LCD Module

After purchasing the display, I attempted to use the sample code provided by SparkFun Electronics. With a minor modification, I was soon able to display alternating vertical bands of black and white bars which proved the display functioned correctly. Now I needed to display my own images. Continue Reading

Jawa EyesFor Halloween this year, my boys decided they wanted to be a Jawa from Star Wars.  One of the requirements was that they have glowing eyes.  Not just any glowing eyes, but orange glowing eyes.  This is how I created some realistic Jawa eyes with just a few dollars of materials.

First, to get the orange glow, I purchased some high intensity orange LEDs (part number 404-1097-ND) from Digi-Key.  They were only $0.71 each.  I also purchased a 9-volt battery clip (part number BS12I-HD-24AWG-ND) for $0.33.  To control the current going to the LEDs, I purchased a 500 ohm potentiometer (part number 3386W-501LF-ND) for $1.29. Continue Reading

Bird Feeder Web CameraBird feeders are a wonderful thing.  Just by placing a small amount of bird seed in the feeder, you can attract a wide variety of wildlife to your backyard.  Unfortunately, this might include some wildlife you might not have anticipated.

The only problem with bird feeders is that once the birds arrive, you must be sitting watching the feeder or you will miss the intended effect, namely, seeing the birds.  Thus, the need arose for a bird feeder that could capture photos of all of the birds that visited my bird feeder. Continue Reading

Doll HouseAbout a year ago, I realized my daughter would need to have a doll house when she turned four.  She doesn’t know she needs one, but I do.  While on a vacation in Duluth, Minnesota, I happened to come across a small store called Teeny Weeny Miniature Cottage in Canal Park.  The owner was nice, and offered numerous tips on building a doll house.  She eventually recommended a kit, and I purchased the Bellingham Farm doll house (BL 455) which is no longer being offered. Continue Reading