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Add boiler plate code for remaining ANSI escapes 

Added function declarations and empty/implementation incomplete
definitions in lcdLib.h and lcdLib.c respectively for remaining ANSI
escape sequences; namely:

- scrollUp
- scrollDown
- eraseDisplay
- eraseInline

Prematurely edited the parsing of any ASCII escape which causes the
screen to be cleared (Eg. '\n' on the last line), to use the new (but
yet to be implemented) scrolling functions; thus after these functions have been
filled in and tested, the ANSI escape support will be complete.

Additionally, escapes that are not supported are passed over without
printing any characters. The two cases that are handled in this commit
are DSR and SGR. The parsing for DSR which when received, normally
prints the current location of the cursor to standard output in the form
"\e[n;mR", where n is the row and m is the column, is left unsupported
but may be supported in the future (thus comments have been left
indicating condition where a valid parse occurs).

The SGR ANSI escape sequence can vary in length and thus needs to be
completely consumed from the input before processing the next character.
This is taken care of correctly in this commit, and has been tested.

In a previous commit, forgot to add the declarations of the following
utility functions to the lcdLib.h header file:

- blinkCursorOff
- blinkCursorOn
- displayOff
- displayOn

There are still a few functions that will be needed for reading
data from the LCD that have not been declared/defined. These functions
are required for efficiently scrolling the screen up and down. They also
will be needed to finish the last remaining piece of this library which,
after completion of ANSI escapes and associated functions, leaves
support for custom characters. Namely writing characters to CGRAM and
displaying custom characters (from CGRAM) using ASCII codes 0-7 (or 0-3
if 5x10 font is used).

Signed-off-by: Collin J. Doering <collin.doering@rekahsoft.ca>
This commit is contained in:
Collin J. Doering 2015-10-25 00:27:51 -04:00
parent 307cd3358c
commit 7c18941836
2 changed files with 163 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

123
lcdLib.c
View File

@ -202,10 +202,13 @@ void writeCharToLCD(char c) {
switch (c) {
case '\n': // Line feed
if (currentLineNum == LCD_NUMBER_OF_LINES - 1) {
clearDisplay();
} else {
writeLCDInstr(INSTR_DDRAM_ADDR | lineBeginnings[++currentLineNum]);
scrollUp(1);
currentLineChars = 0;
writeLCDInstr(INSTR_DDRAM_ADDR | lineBeginnings[currentLineNum]);
} else {
currentLineChars = 0;
writeLCDInstr(INSTR_DDRAM_ADDR | lineBeginnings[++currentLineNum]);
}
break;
case '\a': // Alarm
@ -231,14 +234,20 @@ void writeCharToLCD(char c) {
case '\f': // Form feed
clearDisplay();
break;
default:
default: // Printable character
if (currentLineChars == LCD_CHARACTERS_PER_LINE - 1 && currentLineNum == LCD_NUMBER_OF_LINES - 1) {
clearDisplay();
loop_until_LCD_BF_clear(); // Wait until LCD is ready for new instructions
writeCharToLCD_(c);
scrollUp(1);
currentLineChars = 0;
writeLCDInstr(INSTR_DDRAM_ADDR | lineBeginnings[currentLineNum]);
} else if (currentLineChars == LCD_CHARACTERS_PER_LINE - 1) {
loop_until_LCD_BF_clear(); // Wait until LCD is ready for new instructions
writeCharToLCD_(c);
currentLineChars = 0;
currentLineChars = 0;
writeLCDInstr(INSTR_DDRAM_ADDR | lineBeginnings[++currentLineNum]);
} else {
loop_until_LCD_BF_clear(); // Wait until LCD is ready for new instructions
@ -251,8 +260,9 @@ void writeCharToLCD(char c) {
/*
Given a character string, and a uint8_t pointer, reads the character string until a
non-numerical ASCII character, returning the integer representation of the number read. At
the end of the functions execution, the found_num uint8_t pointer will indicate how many
digits were read.
the end of the functions execution, the found_num uint8_t* will be updated to indicate how
many digits were read. The new_loc char** will be updated with the new parsing position in
the string.
*/
uint8_t readASCIINumber(char* str, uint8_t* found_num, char** new_loc) {
uint8_t nums[3];
@ -362,6 +372,51 @@ void writeStringToLCD(char* str) {
num0 = fnd0 ? num0 : 1;
moveCursorToColumn(num0);
break;
case 'J': // ED - Erase display
num0 = fnd0 ? num0 : 1;
eraseDisplay(num0);
break;
case 'K': // EL - Erase in line
num0 = fnd0 ? num0 : 1;
eraseInline(num0);
break;
case 'S': // SU - Scroll up
num0 = fnd0 ? num0 : 1;
scrollUp(num0);
break;
case 'T': // SD Scroll down
num0 = fnd0 ? num0 : 1;
scrollDown(num0);
break;
case 'm': // SGR - Select graphic rendition (single optional argument)
break;
case ';': // SGR - Select graphic rendition (multiple arguments)
if (fnd0) {
while (fnd0) {
readASCIINumber(++str, &fnd0, &str);
if (fnd0) {
if (*str == 'm') {
break; // Valid SGR
} else if (*str == ';') {
continue; // More SGR parameters yet
} else {
break; // Invalid escape
}
} else {
// Invalid escape; expected SGR parameter
}
}
} else {
// Invalid escape; expected first SGR parameter but none given
}
break;
case 'n': // DSR - Device status report
if (fnd0 && num0 == 6) {
// Valid DSR
} else {
// Invalid DSR
}
break;
default: // Invalid control character
writeCharToLCD(*str);
break;
@ -486,6 +541,58 @@ void moveCursorToColumn(uint8_t n) {
} // else index out of range (off screen column)
}
void eraseDisplay(uint8_t n) {
switch (n) {
case 0: // Clear from cursor to end of screen
case 1: // Clear from cursor to beginning of screen
case 2: // Clear entire screen
clearDisplay();
break;
default: // Invalid argument; do nothing
break;
}
}
void eraseInline(uint8_t n) {
char pos_x = currentLineChars;
// BUG: when cursor is on the last character of the last line, writing currentLineChars
// number of spaces will currently clear the screen due to the way writeCharToLCD handles
// text wrapping. Specifically after the last character (bottom right) of the screen is
// written the screen is automatically cleared.
switch (n) {
case 0: // Clear from cursor to end of line
for (uint8_t i = 0; i < (LCD_CHARACTERS_PER_LINE - currentLineChars); i++)
writeCharToLCD(' ');
// Move cursor back one char and line so its in its original position
setCursorPosition(pos_x, currentLineNum);
break;
case 1: // Clear from cursor to beginning of line
writeCharToLCD('\r');
for (uint8_t i = 0; i < pos_x; i++)
writeCharToLCD(' ');
moveCursorToColumn(pos_x + 1);
break;
case 2: // Clear entire line
writeCharToLCD('\r');
for (uint8_t i = 0; i < LCD_CHARACTERS_PER_LINE; i++)
writeCharToLCD(' ');
// Move cursor back one line so its in its original position
setCursorPosition(pos_x + 1, currentLineNum);
default: // Invalid argument; do nothing
break;
}
}
void scrollUp(uint8_t n) {
}
void scrollDown(uint8_t n) {
}
void saveCursorPosition() {
saveCursorLineNum = currentLineNum;
saveCursorLineChars = currentLineChars;

48
lcdLib.h
View File

@ -207,6 +207,32 @@ void moveCursorPreviousLine(uint8_t n);
*/
void moveCursorToColumn(uint8_t n);
/**
Scroll whole page up by n lines. New lines are added at the bottom.
*/
void scrollUp(uint8_t n);
/**
Scroll whole page down by n lines. New lines are added at the top.
*/
void scrollDown(uint8_t n);
/**
Clears part or all of screen dependent on the value of n:
0 or missing: clear from cursor to end of screen
1: clear from cursor to end of screen
2: clear entire screen
*/
void eraseDisplay(uint8_t n);
/**
Erases part of a line dependent on the value of n:
0 or missing: clear from cursor to end of the line
1: clear from cursor to beginning of the line
2: clear entire line
*/
void eraseInline(uint8_t n);
/**
Hides the cursor
*/
@ -219,6 +245,28 @@ void showCursor(void);
//-----------------------------------------------------------------------------------------------
/**
Turns the cursor blink off.
*/
void blinkCursorOff(void);
/**
Turns the cursor blink on.
*/
void blinkCursorOn(void);
/**
Turns the display off.
*/
void displayOff(void);
/**
Turns the display on.
*/
void displayOn(void);
//-----------------------------------------------------------------------------------------------
/*
UNIMPLEMENTED
*/