I am currently working on a project that will control a string (or individual) RGB LEDs. The RGB LEDs I will be using contain separate Red, Green and Blue LEDs in a single housing. Mixing the amounts of current going through these three colors will vary the total color of the LED package. Doing a little research I found out that there are many different ways to control the brightness of RGB LEDs. Here are a few of them: Amplitude Modulation, Pulsed Amplitude Modulation, Phase Angle Modulation, Pulse Width Modulation (PWM), Frequency Modulation, and Bit Angle Modulation. I will need to investigate these methods of LED control, but I am currently leaning toward PWM or BAM.
If you are ever looking for a good power source for 12 V or 5 V devices, look no further than an old PC power supply. A few simple modifications are all it takes to get one of these to provide clean 12 V and 5 V power. Most modern PC power supplies do not have real "on-off" switches and require the motherboard to tell the power supply to turn on. You can simulate this by connecting the on-off wire (usually green) to the common (usually black). If your power supply is a standard ATX supply, refer to the pinout to verify the location of these pins. You can then use the 5 V (usually red) and 12 V (usually yellow) power pins to your device. These supplies can also supply -12 V & 3.3 V (usually orange). These are also useful for some electronic devices. If you do attempt to convert your old computer power supply be very careful as there are hazardous voltages inside.
How important is a capital letter? It depends on the context, but in many locations it is very important. Case in point, today I was developing a PHP based application and one little capital letter was breaking the whole system. In PHP and many other programming languages capitalization plays an important role in defining different variables and options. For example "spaceTime" and "spacetime" are not the same as far as the code is concerned. If you set "spaceTime" to one and try to read "spacetime" later, it may not equal one. I guess it makes sense, PHP is a programming language much like any other language in that it is used to communicate. It is communication between human and machine. Sometimes a capital letter provides for a cleaner communication, other times it changes the whole meaning.
Here is a neat look at the technologies, prototypes, and innovations of the company behind the Roomba: iRobot.
For a mobile robot, the measurement of distance is an important piece of information needed for it to help determine where it is in the world. It is also very important to keep it from running into things. Gamma can now measure the distance in front of it to the nearest object. It does this using the Ping))) sensors mounted on the front of it. Since Gamma uses the Propeller as its processor the code for the ping can be found in the OBEX. This takes the complexities of converting microseconds between pulses to lines as simple as "range := ping.Inches(PING_CENTER)" where "range" is the variable for storing the distance, and "PING_CENTER" is the IO pin that the ping is connected to. Click "Read More" to see (and download) a sample program that reads the distances from 3 pings and displays them on the terminal. Note: this requires use of the Parallax Serial Terminal library.
The Stingray platform is a robotics development platform from Parallax. I will be using this platform to expand my knowledge of robotics and explore my interests in mobile robotics and mapping. In order to do that Gamma (as every good robot needs a name) has been equipped with 3 Parallax Ping sensors. These sensors use ultrasonic pulses to measure distance to other objects. More about this as the investigation continues.
Do you wonder how the internet works? How your computer finds a site that's out there and brings the information back for you to consume? It's a tangled web of computers, servers, switches and cables. To fix an issue I was having with my website today I used a command line command called "tracert". This command can show all the points along a path from your computer to the website you specify. If you want to try this command out for yourself follow these steps.
1] click the windows orb
2] type "cmd"
3] type "tracert" then the website you want to trace the route to.
Now you know the steps it takes to get from your computer to your favorite website (and back).
The Javelin Stamp was the first real microcontroller I used. It ran a subset of Java and was able to be programmed using standard Java based programming structures and syntax. Today I was poking around the manufactures website and noticed it no longer exists for sale. It had been EOLed a few years ago, but now it can be officially reported as retired. I have created a few different products (for example Bell Controller 1.0) that use them as the brain of the device so they will continue to live on in them. So long little Javelin Stamp, I for one will miss your simplicity and ease of use.
Has Windows reported that your hard drive is failing? If you have, heed its warning and backup your files immediately. I am currently trying to recover files from such a device. It's difficult, to say the least. One of the most difficult aspects of a failing hard drive is recovering the files from the user folders. Copy these files to your backup choice as quickly as possible. These files are password protected so moving the drive to a new machine and attempting to copy them is not as easy as copy and paste.
If you ever find yourself trying to copy files from an old hard drive that is failing, or otherwise has files tucked away in a user account folder, here are a few tricks you can use to unlock the files for access, after all, it's your data anyway.
1] Install the "Take Ownership" Registry hack and use as described.
2] Use the security tab to give the administrator access.
3] Copy files in as small of groups as possible to reduce load on the failing HD.
This blog covers a multitude of up and coming technology, as well as how to guides, tips and tricks, and other interesting technology related items.