Display Drivers¶

EVA Boxy supports multiple display types through a unified interface. All positioning uses tiles as the minimum unit. The library provides both graphical and text-based display drivers, including debug variants for development.

Display Types¶

Graphical Displays¶

Pixel-based displays that can render fonts and pictograms:

Driver	Class	Resolution	Interface
SSD1306	`ScreenSSD1306`	16x8 tiles	I2C
SSH1106	`ScreenSSH1106`	16x8 tiles	I2C
PCD8544	`ScreenPCD8544`	12x6 tiles	SPI
KS0108	`ScreenKS0108`	16x8 tiles	Parallel

Text Displays¶

Character-based displays with limited graphics:

Driver	Class	Resolution	Interface
LCD I2C	`ScreenLCD_I2C`	16x2, 20x4, etc.	I2C

Debug Displays¶

Virtual displays for development and testing:

Driver	Class	Resolution	Output
Serial Text	`ScreenSerialText`	16x8 tiles	Serial
Serial Pixel	`ScreenSerialPixel`	16x8 tiles	Serial

Graphical Display Drivers¶

ScreenSSD1306 - OLED Display¶

I2C OLED display driver for 128x64 pixel screens.

#include <evabScreenSSD1306.h>
#include <evabFont8Compact.h>

evab::Font8Compact font;
evab::ScreenSSD1306 screen(&font, 800000L, 64);

ScreenPCD8544 - Nokia 5110 Display¶

SPI-based driver for Nokia 5110/3310 displays.

#include <evabScreenPCD8544.h>
#include <evabFont8Bold.h>

evab::Font8Bold font;
evab::ScreenPCD8544 screen(
    &font,
    9,   // RST pin
    10,  // CE pin
    11,  // DC pin
    12,  // DIN pin
    13,  // CLK pin
    8    // LED pin (optional)
);

// Control backlight
screen.SetBacklight(HIGH);

// Adjust contrast
screen.SetContrast(0x30);  // 0x00-0x7F

ScreenKS0108 - Parallel Graphics¶

Parallel interface driver for KS0108-based displays.

#include <evabScreenKS0108.h>
#include <evabFont8Thin.h>

evab::Font8Thin font;
evab::ScreenKS0108 screen(
    &font,
    2,   // RS
    3,   // RW
    4,   // E
    5,   // CS1
    6,   // CS2
    7,   // DB0
    8,   // DB1
    9,   // DB2
    10,  // DB3
    11,  // DB4
    12,  // DB5
    13,  // DB6
    14,  // DB7
    15   // LED (optional)
);

ScreenSSH1106 - Alternative OLED¶

I2C driver for SSH1106-based OLED displays.

#include <evabScreenSSH1106.h>
#include <evabFont8Compact.h>

evab::Font8Compact font;
evab::ScreenSSH1106 screen(&font, 800000L);

Text Display Drivers¶

ScreenLCD_I2C - I2C LCD¶

Driver for HD44780-based LCD displays via I2C.

#include <evabScreenLCD_I2C.h>

evab::ScreenLCD_I2C screen(
    0x27,  // I2C address
    16,    // Columns
    2,     // Rows
    3      // Backlight pin (on PCF8574)
);

// Control backlight
screen.SetBacklight(HIGH);

Debug Displays¶

Debug displays output to Serial for development without hardware.

ScreenSerialText - Text Debug¶

Displays characters as-is on serial monitor.

#include <evabScreenSerialText.h>

evab::ScreenSerialText screen;

// Draw text
screen.TextCenter({0, 0}, {16, 8}, "Debug", 0);

// Output to serial
screen.printToSerial();

/* Output:
................
................
....Debug.......
................
................
................
................
................
*/

ScreenSerialPixel - Pixel Debug¶

Displays pixel-accurate representation.

#include <evabScreenSerialPixel.h>
#include <evabFont8Compact.h>

evab::Font8Compact font;
evab::ScreenSerialPixel screen(&font);

// Draw something
screen.TextCenter({0, 0}, {16, 8}, "8", 0);

// Output to serial
screen.printToSerial();

/* Output:
...####...........
..#....#..........
..#....#..........
..######..........
..#....#..........
..#....#..........
..######..........
..................
*/

Fonts¶

All graphical displays require a font to be specified during initialization.

Available fonts:

Font8Bold - Bold 8-pixel font
Font8Compact - Compact 8-pixel font (narrower characters)
Font8Sharp - Thin 8-pixel font