rekahsoft/avr-lcd-lib
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Working backspace and fixed bug with cursor

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Before this commit the cursor would be incremented (automatically by
hardware) after printing the last character on the line, which would
leave it the next line in memory, which doesn't necessarily correspond
to the next physical line on the display. This would be corrected when
the next character is received but is incorrect behavior; the cursor
should always be at where the next character is to inserted. This was
due to an off-by-one logical error. This commit solves this bug.

Along with the bug fix, keycodes from the serial terminal are now
deciphered correctly and the corresponding key or keys are sent to the
LCD accordingly.

Further work is required with regards to updating the serial
console (the connected client) so that their serial console looks
exactly like the LCD they are connected to.

Signed-off-by: Collin J. Doering <collin.doering@rekahsoft.ca>
This commit is contained in:
Collin J. Doering 2015-10-07 22:38:57 -04:00
parent 3a6800a2b0
commit 3d3b9ab5fb
2 changed files with 44 additions and 14 deletions
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41
lcdLib.c
View File

@ -200,7 +200,19 @@ void writeCharToLCD(char c) {
case '\a': // Alarm
break;
;
case '\b': // Backspace
case '\b': // Backspace (non-destructive)
if (currentLineChars == 0 && currentLineNum == 0) {
// At first line, first column; there is no where to move; do nothing
break;
} else if (currentLineChars == 0) {
// At beginning of line, need to move the end of previous line
currentLineChars = LCD_CHARACTERS_PER_LINE - 1;
writeLCDInstr(INSTR_DDRAM_ADDR | (lineBeginnings[--currentLineNum] + currentLineChars));
} else {
// OK, simply go back one character
writeLCDInstr(INSTR_DDRAM_ADDR | (lineBeginnings[currentLineNum] + --currentLineChars));
}
break;
;
case '\r': // Carriage return
@ -208,19 +220,24 @@ void writeCharToLCD(char c) {
currentLineChars = 0;
break;
;
case '\f': // Form feed
clearDisplay();
break;
;
default:
if (currentLineChars == LCD_CHARACTERS_PER_LINE) {
if (currentLineNum == LCD_NUMBER_OF_LINES - 1) {
clearDisplay();
} else {
writeLCDInstr(INSTR_DDRAM_ADDR | lineBeginnings[++currentLineNum]);
currentLineChars = 0;
}
}
if (currentLineChars == LCD_CHARACTERS_PER_LINE - 1 && currentLineNum == LCD_NUMBER_OF_LINES - 1) {
clearDisplay();
} 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;
loop_until_LCD_BF_clear(); // Wait until LCD is ready for new instructions
writeCharToLCD_(c);
currentLineChars++;
writeLCDInstr(INSTR_DDRAM_ADDR | lineBeginnings[++currentLineNum]);
} else {
loop_until_LCD_BF_clear(); // Wait until LCD is ready for new instructions
writeCharToLCD_(c);
currentLineChars++;
}
;
}
}

17
lcdOutput.c
View File

@ -46,8 +46,21 @@ int main(void) {
while (1) {
serialChar = receiveByte();
writeCharToLCD(serialChar);
transmitByte(serialChar); // Echo character back to serial console
switch (serialChar) {
case '\r':
writeStringToLCD("\r\n");
break;
;
case 0x7f: // Backspace (sent as delete)
writeStringToLCD("\b \b");
break;
;
default:
writeCharToLCD(serialChar);
transmitByte(serialChar); // Echo character back to serial console
;
}
}
return 0;