LED Controller
A typical LED circuit will consist of three major components including the current source, buffer, and logic controller. The current source simply monitors the drive current as it flows through the LED array. If the current begins to vary for any reason, the current source will compensate accordingly. The buffer acts a switch to turn each light emitting diode on or off. However, the buffer contains no intelligence, so it relies on the logic portion of the LED controller for guidance. When the logic controller tells the buffer to turn an LED light on or off, it does so without hesitation. Most logic controllers utilize an embedded microcontroller integrated circuit. The microcontroller normally features numerous ports available for input and output commands. Within the LED light controller, output ports or pins connect directly to the LED drivers. Input ports or pins can connect to external circuits, sensors, or switches. In a custom LED lighting design utilizing a switch, the human can indicate his or her commands by simply depressing or holding a single push button switch. This microcontroller interprets this input signal according to firmware, preprogrammed by an engineer. The firmware contains a set of very specific rules for operation, which translates to turning an light emitting diode on or off as necessary.
Programming an LED Light Controller
The advantages of the microcontroller are virtually limitless. The microcontroller, a single electronic component smaller than a pencil eraser, operates according to a very specific program defined by the software designer. The engineer designs this software specifically for the LED controller using a standard computer application, and then downloads the software into the microcontroller in the form of a hex file. Once installed, the microcontroller will perform strictly according to software commands. Anytime a revision is required, the engineer can perform a simple software update. After downloading new software into the microcontroller, the LED light controller will begin to perform according to updated software.
Chasing LEDs
A custom program within the LED controller can perform a series of pre-defined functions. For example, a row of linear LEDs will perform a sequential chasing LEDs routine from left to right, in 10-second intervals. In addition, the chasing LEDs will change colors every 16 cycles. Output functions such as these, allow the microcontroller to perform a wide variety of tasks. Another interesting capability of the LED light controller referred to as an input function, allows the device to receive intelligence from the outside world. Sources of input may include switches, sensors, or other LED controller devices. Although the microcontroller can only perform a single function within any given moment, it can perform that function extremely fast. A typical LED controller will process approximately one million instructions per second. The raw speed of the device allows it to perform a large number of tasks very efficiently.
Human Interfacing
Many common household electronic devices contain an array of push buttons and switches. Every additional switch added to an appliance does not only consume additional space, but also increases the overall manufacturing cost of that item. Many custom LED lighting designs are capable of utilizing only a single push button switch as opposed to a control panel containing numerous controls. Not only can this save money and physical space, but also greatly simplifies the user interface. Within the LED circuitry, a microcontroller can translate commands from a single switch into an array of operating commands, as predetermined by an engineer. For example, a single short depression of the switch can cause the LED light controller to cycle through modes, where each mode is associated with a specific LED color. Holding the switch for three seconds commands chasing LEDs from left to right, but while maintaining the previously selected color mode. While chasing LEDs perform, the user can also change LED colors by simply pressing the switch once. Two subsequent switch depressions, similar to the double click of your computer mouse, can cause the LED chase sequence to switch directions. When the user decides it is time to discontinue operation altogether, he or she would depress and hold the push button for ten seconds. This will cause the LED controller to proceed into sleep mode, and discontinue all light emitting diode operation.