Unit AF16x2LCD
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Description
The Adafruit 16x2 LCD + Keypad is a kit that includes both a 16x2 LCD display using the Hitachi HD44780 LCD controller as well as a custom PCB with an MCP23017 I/O expander to connect it to a Raspberry Pi (any model) using I2C. It is available in Monochrome or RGB Positive and Negative versions.
This unit ties together the various components needed to make one of these boards work with Ultibo by finding the correct I2C device, creating the MCP230XX GPIO device, creating the HD44780 Console device and registering all of it with the correct parameters for the Adafruit kit.
The unit also includes functions to read the 5 buttons on the board and control the LCD backlight.
You will find many LCD display boards based on the Hitachi HD44780 controller and this unit gives an example of how to assembler the available units to create your own driver for a different board.
Constants
To be documented
Type definitions
To be documented
Public variables
To be documented
Function declarations
Initialization functions
procedure AF16x2LCDInit;
| Note | Called only during system startup |
|---|
function AF16x2LCDStart(Model:LongWord;Invert:Boolean; const Device:String; Address:Word):THandle;
| Model | The Adafruit 16x2 LCD Plate model (eg AF16X2LCD_MODEL_RGB) | |
|---|---|---|
| Invert | Invert the signal level for the LCD backlight (If True then GPIO_LEVEL_LOW equals On) | |
| Device | The I2C device that the MCP23017 I/O Expander on the LCD Plate is connected to | |
| Address | The I2C address of the MCP23017 I/O Expander on the LCD Plate | |
| Return | The handle of the AF16x2LCD on success or INVALID_HANDLE_VALUE on failure | |
| Note | This function will be called during startup if the parameter AF16X2LCD_AUTOSTART is True | Can be called multiple times to support more than one 16x2 LCD display |
function AF16x2LCDStop(Handle:THandle):Boolean;
| Handle | The handle of the AF16x2LCD or INVALID_HANDLE_VALUE for the default display |
|---|---|
| Return | True if completed or False on failure |
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