mangavalk/lcdproc
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* Automatically exclude the pin for switchable backlight from keypad scanning

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in the 4bit and 8bit wiring. This fixes problems with flickering backlight if
  a slow parallel port is used. IMPORTANT: This may require a hardware change!
* In code comments use the same line names as in the user's guide (Y1/X1
  instead of Y0/X0).
* Add documentation about hd44780-ftdi's 4bit mode.
This commit is contained in:
mmdolze
2010-01-18 22:24:59 +00:00
parent 6fba5cef68
commit 59f3cbdb45
6 changed files with 208 additions and 64 deletions
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server/drivers/hd44780-ext8bit.c
+21 -21
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@@ -27,21 +27,21 @@
* Keypad connection (optional):
* Some diodes and resistors are needed, see further documentation.
* printer port keypad
* D0 (2) Y0
* D1 (3) Y1
* D2 (4) Y2
* D3 (5) Y3
* D4 (6) Y4
* D5 (7) Y5
* D6 (8) Y6
* D7 (9) Y7
* nSTRB (1) Y8
* nSEL (17) Y9
* nACK (10) X0
* BUSY (11) X1
* PAPEREND (12) X2
* SELIN (13) X3
* nFAULT (15) X4
* D0 (2) Y1
* D1 (3) Y2
* D2 (4) Y3
* D3 (5) Y4
* D4 (6) Y5
* D5 (7) Y6
* D6 (8) Y7
* D7 (9) Y8
* nSTRB (1) Y9
* nSEL (17) Y10 (optional, only if no backlight is used)
* nACK (10) X1
* BUSY (11) X2
* PAPEREND (12) X3
* SELIN (13) X4
* nFAULT (15) X5
*
* Created modular driver Dec 1999, Benjamin Tse <blt@Comports.com>
*
@@ -179,7 +179,7 @@ void lcdtime_HD44780_backlight(PrivateData *p, unsigned char state)
/**
* Read keypress.
* \param p Pointer to driver's private data structure.
* \param YData ???
* \param YData Bitmap of rows / lines to enable.
* \return Bitmap of the pressed keys.
*/
unsigned char lcdtime_HD44780_readkeypad(PrivateData *p, unsigned int YData)
@@ -188,19 +188,19 @@ unsigned char lcdtime_HD44780_readkeypad(PrivateData *p, unsigned int YData)
sem_wait(semid);
// 10 bits output or 8 bits if >=2 displays
// Convert the positive logic to the negative logic on the LPT port
port_out(p->port, ~YData & 0x00FF);
if (p->numDisplays<=2) {
// Can't combine >3 displays with >8 keypad output lines
// 9 bits output if backlight is used, 10 bits otherwise
if (p->have_backlight)
port_out(p->port + 2, (((~YData & 0x0100) >> 8) | p->backlight_bit) ^ OUTMASK);
else
port_out(p->port + 2, (((~YData & 0x0100) >> 8) | ((~YData & 0x0200) >> 6)) ^ OUTMASK);
}
if (p->delayBus) p->hd44780_functions->uPause(p, 1);
// Read inputs
readval = ~ port_in(p->port + 1) ^ INMASK;
// Put port back into idle state for backlight
// Put port back into idle state
port_out(p->port, p->backlight_bit ^ OUTMASK);
sem_signal(semid);