A few months ago, I saw an instructable by fjordcarver on how to build a color sensor with an RGB led and an LDR. It inspired me to try whether I could improve his design. Here are the things that I wanted: The sensor should have as few pins as possible. It should work as …
The temperature in my office at work varies quite a bit depending on the time of day, season, and the whims of the other people I share the floor with. When I’m sitting at my desk shaking uncontrollably or sweating profusely it would be nice to know if it’s due to the temperature or just …
Tempduino – Arduino Based Temp and Humidity Display Read More »
This article looks at the options for getting started with a GPS design for industrial applications, from the transceivers to modules and the evaluation boards available, as well as the antenna issues to consider. It looks at how modules from suppliers such as Antenova and NXP Semiconductors can be used, extending to single chip implementations …
I love robots. Normally the ones I build are quite large and wouldn’t fit in your pocket, but for a change of pace I decided I would try something small and fun! This robot is exactly that, and in fact fits inside of an altoids tin. It is inexpensive, versatile (so many different sensors can …
A circuit that properly charges sealed lead-acid batteries ensures long, trouble-free service. Fig 1 is one such circuit; it provides the correct temperature-compensated charge voltage for batteries having from one to as many as 12 cells, regardless of the number of cells being charged. The Fig 1 circuit furnishes an initial charging voltage of 2.5V …
This is a open source project of RC Car with control from Android Phone via Bluetooth. The controller is used with .NET Micro Framework: FEZ Panda II, but you may use any controller works with .NET Micro Framework core (Net dui no, GHI Electronics board’s and other). All source code is available at Git Hub. …
CxemCAR 1 – Android Control RC Car over Bluetooth Read More »
Switching DC/DC voltage converters are popular because they provide efficient power conversion that can exceed 90 percent. That is an advantage both when input power is at a premium and when it is difficult to get the heat out (common challenges for engineers designing compact portable products). With key power component manufacturers offering products that …
Selecting the Right Voltage Converter Is Not Just About Peak Efficiency Read More »
This is a small project to get you started with the electric imp and a Thermistor so you can see how you can get temperature readings updating live on a web site. This instruct able will address both the hardware and the web site along with all the parts in between. I’ve tried to keep …
Suppose that you need to test a 1.5V, AA-size alkaline battery. You can apply a short circuit and measure current, or you can measure open-circuit voltage, but neither method properly tests the battery. A suitable test current of approximately 250 mA gives you a more reasonable test. You can use a 6Ω resistive load at …
Circuit provides constant-current load for testing batteries Read More »
This voltage monitor has been designed to remotely display battery voltage so that people monitor and maintain their batteries easily. It was designed for use on off-grid renewable energy systems (such as my solar PV system), but it would also be useful to anyone who has a lead-acid battery, such as caravans, boats and cars. …
