Summary of LCD interfacing with arduino
This tutorial explains how to connect a 16x2 parallel LCD to an Arduino using a 4-bit interface to minimize IO pin usage. It outlines the connections for 10 essential pins of the 16-pin LCD, including power, ground, contrast adjustment with a 1K Ohm resistor, and data pins connected to specific Arduino digital pins. The guide recommends connecting the Read/Write pin to ground to simplify operation by enabling only write mode, and adjusting contrast with a fixed resistor instead of a variable one for stability.
Parts used in the 16x2 LCD Arduino Interface Project:
- 16x2 LCD Display
- Arduino Board
- Connecting wires
- 1K Ohm Resistor
In this tutorial we’ll be looking at how to connect interface parallel LCD to an Arduino. We are using 16 char x 2 Line LCD known as 16×2 LCD, you can usually identify this display by the 16-pin interface. You only need to solder 10 of the 16 wires to use the LCD, but this will only enable you to use the 4-bit interface. 4-Bit interface helps us to reduce required IO lines, there are various displays available such as 16×2, 16×4, 20×2, 20×4 LCD Display.
Step 1: Components Required
- 16×2 LCD
- Arduino Board
- Connecting wires
- 1K Ohm Resistor
Step 2: Circuit diagram/connections
- Most of the time we don’t need to read the display so we always write on the display. Pin 5 RD/WR when it is connected to logic 0, It is write operation, to reduce IO requirement we connect it to GND (Logic 0 Always Write)
- Contrast setting, LCD contrast can be adjusted by setting proper voltage at Pin 3. Connecting variable resistor takes lot of space and possibility of setting wrong contrast value due to change in resistance with change in atmospheric condition. I use 1KOhm resistor between GND and Pin 3. It gives perfect contrast setting.
As I mentioned before, you only need to connect 10 pins. Solder jumpers to these wires:
Pin 1 – Ground
Pin 2 – +5V
Pin 3 – Contrast Adjustment (1K Ohm resistor to GND)
Pin 4 – Register Select
Pin 5 – Read/Write (Connect to GND)
Pin 6 – H/L Enable
Pin 11 – DB4
Pin 12 – DB5
Pin 13 – DB6
Pin 14 – DB7
As shown in the picture below:
Pin 1 to GND
Pin 2 to 5V
Pin 3 to (1K Ohm resistor to GND)
Pin 4 to Arduino pin 12
Pin 5 to GND
Pin 6 to Arduino pin 11
Pin 11 to Arduino pin 5
Pin 12 to pin 4
Pin 13 to pin 3
Pin 14 to pin 2
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