Guide Connecting Newhaven Lcds to Arduino Via SPIRS232

LCD displays serve as the "eyes" of Arduino projects, transforming code into visible text and graphics. For makers and engineers alike, integrating a display can elevate projects from abstract concepts to interactive experiences. This guide explores how to connect Newhaven's 16×2 character LCD to an Arduino UNO board using both SPI and RS232 TTL serial communication methods.

Character LCDs remain popular for Arduino projects due to their simplicity and effectiveness in conveying information. The 16×2 format (16 characters across 2 lines) provides sufficient space for status messages, sensor readings, or simple user interfaces. Newhaven's NHD-0216K3Z-NSW-BBW-V3 model offers particular advantages with built-in serial interfaces that reduce wiring complexity.

• 16×2 LCD display (Newhaven NHD-0216K3Z-NSW-BBW-V3 recommended)
• Single-row pin header connectors
• Arduino UNO board
• Breadboard and jumper wires
• Soldering equipment (iron and solder)
• USB A-to-B cable
• Arduino IDE software
• 0-ohm resistor (optional, for SPI communication)

The Newhaven display features two communication ports:

SPI (Serial Peripheral Interface) offers high-speed synchronous communication ideal for short-distance connections between Arduino (master) and LCD (slave). The connection requires five wires:

Note: Enabling SPI requires opening R1 and shorting R2 on the display PCB as specified in the datasheet.

The Arduino code for SPI communication includes several essential functions:

• SPI_Out() - Transmits commands and data to the LCD
• Set_Pins() - Configures SPI pins as outputs
• Set_Contrast() - Adjusts display contrast
• Set_Backlight() - Controls backlight intensity
• Clear_Display() - Clears the LCD screen
• Set_Cursor() - Manages cursor visibility

For simpler setups, RS232 TTL requires only three connections:

Note: Both R1 and R2 must be open on the display PCB to enable RS232 TTL mode.

When encountering problems with your Arduino-LCD setup, consider these diagnostic steps:

1. Verify wiring connections: Cross-check all connections against the provided diagrams.
2. Inspect components: Look for physical damage on the Arduino, LCD, or connecting wires.
3. Validate code: Ensure uploaded sketches are error-free and properly configured.
4. Check power supply: Confirm adequate power for both Arduino and LCD.
5. Test with known-good LCD: Isolate the problem by trying a different display.
6. Adjust contrast: Use Set_Contrast() to optimize visibility.
7. Update Arduino IDE: Ensure you're using the latest software version.
8. Test individual functions: Start with basic "Hello World" examples to isolate issues.

By following these guidelines and understanding both communication methods, makers can effectively integrate LCD displays into their Arduino projects for enhanced functionality and user interaction.