LCD

The LCD character display can be used in three different ways:

• Output ASCII characters over a simple LCD controller
• Output binary values in HEX representation (max. 128 bit)
• Access the display directly over the I²C interface

Each colour of the background light is controlled by a 16 bit PWM controller.

Please make sure the CT Board is in the correct mode.
Supported modes: 1, 2, 3

The integrated LCD controller must allways be accessed with 16 bit half words!

The code snippet bellow shows how to use the ASCII interface of the LCD.

#include "reg_ctboard.h"
 
CT_LCD->ASCII = (uint16_t) ((13u << 8u) | ascii_char);    /* Write ascii_char at position 13 on the LCD. */

ADDR_LCD_ASCII  EQU      0x60000310
 
                LDR      r0, =ADDR_LCD_ASCII
                LDR      r1, #13                          ; Load position on display into r1.
                LDR      r2, "E"                          ; Load value of ASCII char 'E' into r2.
 
                ; Thumb instruction set
                LSLS     r1, #8                           ; Shift position 8 bits to the left
                ORRS     r2, r1                           ; Combine position with ASCII character
 
                ; ARM instruction set
                ORRS     r2, r1, LSL #8                   ; Shift and combine position value with ASCII character
 
                STRH     r2, [r0, #0]                     ; Write ascii_char at position 13 on the LCD.

The Registers are read / write.

The binary interface can be used to display binary values in HEX representation. A maximum of 128 bits can be displayed.

The code snippet bellow shows how to use the ASCII interface of the LCD.

#include "reg_ctboard.h"
 
CT_LCD->BIN.BYTE.B7_0 = (uint8_t) data_byte;           /* Write byte of data to LCD. */
CT_LCD->BIN.HWORD.B15_0 = (uint16_t) data_halfword;    /* Write halfword of data to LCD. */
CT_LCD->BIN.WORD.B31_0 = (uint32_t) data_word;         /* Write word of data to LCD. */
CT_LCD->BIN.DWORD = (uint64_t) data_doubleword;        /* Write doubleword of data to LCD. */

The Registers are read / write.

Each colour of the background light is controlled by a 16 bit PWM generator.
The brightness can be regulated from 0x0000 (0% / off) to 0xffff (100%). To adapt the brightness curve to the human eye a adadption to a logarithmic scale has to be done manually.

The code snippet bellow shows how to set the background light on the LCD.

#include "reg_ctboard.h"
 
CT_LCD->BG.RED = (uint16_t) data_halfword;        /* Set PWM value for red background light. */
CT_LCD->BG.GREEN = (uint16_t) data_halfword;      /* Set PWM value for green background light. */
CT_LCD->BG.BLUE = (uint16_t) data_halfword;       /* Set PWM value for blue background light. */

ADDR_LCD_BG     EQU      0x60000304
 
                STRH     r1, [r0, #0]                     ; Set PWM value for red background light.
                STRH     r1, [r0, #2]                     ; Set PWM value for green background light.
                STRH     r1, [r0, #4]                     ; Set PWM value for blue background light.

The Registers are read / write.