Here is my new Frequency meter who was done with a LCD’s cellular phone!!! This is a simple project. The Frequency is passing through an op-amp to convert it in a square wave. The ouput of the op-amp is feeding the 3*8 bits counter (24 bits) who can accumulate at a maximum of 16777216 count.
Frequency Meter – [Link]
There are two major types of backlights for LCDs: LEDs, which stands for light emitting diode, or EL, which stands for electroluminescent. EL backlights tend to be more efficient and have more uniform lighting than LED ones, but they require some tricky circuitry to drive. If you’ve heard of Organic LED displays, or OLEDs, that’s basically an array of electroluminescent strips shunk down to the size of individual pixels.
Build a LCD Backlight – Electroluminescent Inverter - [Link]