Intro: How to Interface 16X2 LCD With AVR Microcontroller
Here is the circuit diagram of Interfacing 16X2 LCD to AVR Microcontroller. In this circuit, the crystal oscillator will provide the clock to the microcontroller. The capacitors connected to the crystal will act as filters and help the crystal to resonate and oscillates to its parallel resonate mode.
The potentiometer which is connected to the pin 3 and pin2 of LCD will help to adjust the contrast of the LCD. The 4, 5 and 6 pins of LCD that is Register select, Read/write and Enable pins are connected to the PD0, PD1 and PD2 pins of Atmega16. The data pins of LCD are connected to the pins of 33 to 40 pins of Atmega16.
For detailed information about the code and working of this circuit, read the post - How to Interface 16X2 LCD with AVR