Connect pins 5 to 2 of the Arduino to pins D4 to D7 of the LCD, respectively. Since we are using the 4-bit mode, we can omit the data pins D0 to D3. Due to the fact that, in this tutorial, we only want to write something to be displayed in the LCD, we can connect pin RW of the LCD directly to ground, since, when the signal in this pin is zero (low), it is set to write to the register, whereas, when the signal is one (high), the LCD is set to read from the register. Next, connect the digital pins 9 and 8 of the Arduino to the RS and E pins of the LCD, respectively. Connect the first terminal to 5 Volts, the middle terminal to the LCD’s V E pin and the third pin of the potentiometer to ground. Then, in order to adjust the contrast of the character pixels, we can use a 10kΩ potentiometer. With this in consideration, we can begin to connect our circuit, which schematic is represented in Figure 3.įirst, connect the V SS and V DD to ground and 5 Volts, respectively. Finally, the backlight anode and backlight cathode pins are used to connect the background LED of the display. After that, the enable (E) pin functions like a trigger, sending the information to the data pins of the LCD when a high to low pulse is given, followed by the 8 data pins (D0-D7). Next, the read/write (RW) pin is the pin that either enables us to write the characters we want to the LCD (write mode) or to read the characters from it (read mode). initialize it, clear the screen, scroll the screen, etc.), while the data register stores the data to be displayed in its ASCII value. The command register stores the command instructions were given to the LCD (e.g. Then, the register select pin (RS) is responsible for selecting the command and data registers. If you are using a different LCD display, these pins may not be the same, so be sure to check them in their corresponding datasheet before you connect them to your Arduino.Īfter the power pins (V SS and V DD), we can see that there is a pin (V E) used to adjust the contrast of the character pixels, which can be very helpful depending on the light conditions where we are using our LCD. To facilitate, a diagram of the LCD pins is shown in Figure 2. Circuitįrom the LCD’s datasheet, we have access to its pins’ interface description. For that reason, in this tutorial, we are going to use the 4-bit mode, which, besides its inherent latency, does not present a significant difference in performance. After that, the character is displayed on the LCD.Īlthough the 8-bit mode seems straightforward, it requires four additional digital pins from our microcontroller to work, which can be a problem for people using other boards with less digital pins, like ESP8266 NodeMCU or similar.

Hence, the LCD receives only 4 bits at a time, starting with the high order bits and followed by the low order bits. Regarding the 4-bit mode, only 4 data pins are required, but the 8 bits of the character have to be divided in two.

In the 8-bit mode, the 8 data pins of the LCD are required so that the 8-bit ASCII value of the character can be sent simultaneously to the LCD. From this LCD’s datasheet, we can see that it can be connected considering two possible modes: 4-bit mode or 8-bit mode. One useful thing we always should have when working with any piece of hardware is its corresponding datasheet since it contains all the hardware’s important information.

Pin diagram arduino mega 2560