Teacup_Firmware/display_hd44780.c

131 lines
2.9 KiB
C

/** \file
\brief Code specific to the HD44780 display.
*/
#include "display.h"
#if defined TEACUP_C_INCLUDE && defined DISPLAY_TYPE_HD44780
#include "displaybus.h"
#include "delay.h"
#include "sendf.h"
#include "dda.h"
/**
* Initializes the display's controller configuring the way of
* displaying data.
*/
void display_init(void) {
// Minimum initialisation time after power up.
delay_ms(15);
displaybus_init(0);
// Write left to right, no display shifting.
displaybus_write(0x06, parallel_4bit_instruction);
// Display ON, cursor not blinking.
displaybus_write(0x0C, parallel_4bit_instruction);
}
/**
Show a nice greeting. Pure eye candy.
*/
void display_greeting(void) {
display_clear();
// We have only 16 characters at our disposal ...
display_writestr_P(PSTR("Welcome @ Teacup"));
// Forward this to the display immediately.
while (buf_canread(display)) {
display_tick();
}
// Allow the user to worship our work for a moment :-)
delay_ms(5000);
}
/**
Regular update of the display. Typically called once a second from clock.c.
*/
void display_clock(void) {
static uint8_t pos = 0;
display_clear();
update_current_position();
sendf_P(display_writechar, PSTR("X:%lq Y:%lq"),
current_position.axis[X], current_position.axis[Y]);
/**
This is a tiny demo showing how cursor positioning works. The
four-character text should move along the second display line.
*/
display_set_cursor(1, pos);
display_writestr_P(PSTR("ick!"));
pos++;
if (pos >= DISPLAY_SYMBOLS_PER_LINE) {
pos = 0;
}
}
/**
Forwards a character or a control command from the display queue to display
bus. As this is a character based display it's easy.
*/
void display_tick() {
uint8_t data, command;
if (displaybus_busy()) {
return;
}
if (buf_canread(display)) {
buf_pop(display, data);
switch (data) {
case low_code_clear:
displaybus_write(0x01, parallel_4bit_instruction);
break;
case low_code_set_cursor:
/**
Set the cursor to the given position.
This is a three-byte control command, so we fetch additional bytes
from the queue and cross fingers they're actually there.
*/
command = 0x80; // "Set DDRAM Address" base command.
/**
Add address of line.
As we have two lines only, this can be "calculated" without
a multiplication.
*/
buf_pop(display, data);
if (data) {
command += 0x40;
}
// Add column address.
buf_pop(display, data);
command += data;
displaybus_write(command, parallel_4bit_instruction);
break;
default:
// Should be a printable character.
displaybus_write(data, parallel_4bit_data);
break;
}
}
}
#endif /* TEACUP_C_INCLUDE && DISPLAY_TYPE_HD44780 */