[En-Nut-Discussion] new to nutos usage
Ulrich Prinz
uprinz2 at netscape.net
Tue Jun 22 18:45:59 CEST 2010
Hi!
I wrote / reorganized the latest code for a character lcd on an at91
board like en3.x or EIR.
The driver is almost valid for any kind of CPU bus as I don't have any
AVR driven ethernut device, I cannot test. That's the reason why I kept
it in arch/arm/dev instead moving it to /dev.
So if you take this driver as an example the porting should not be very
difficult.
Best regards, Ulrich
Am 21.06.2010 12:57, schrieb Paolo Simoncelli:
>
> Hi all,
>
> sorry zvonko, but i have had no good luck with LCD displays
> and ethernut, here is my experience:
>
>
> At first i haven't been able to make Jose's code work,
>
> it's using the builtin driver: (quite old post ...)
> http://lists.egnite.de/pipermail/en-nut-discussion/2007-March/007990.html
>
> maybe there's an open bug for that:
> http://sourceforge.net/tracker/?func=detail&aid=2995417&group_id=34079&atid=410687
> (BTW i will be glad to contribute for a fix ;-) )
>
> Next i went to the code reported on "Ethernut application note 001"
> but it did not even compiled at first (some editing needed,
> maybe it refers to old NutOS/Ethernut versions) anyway no luck at all :-(
>
> So, based on appnote001 sw& hw wiring, i wrote my own code,
> here follows a basic example, i have left the appnote001 comments
> plus some spaghetti programming examples ;-)
> sorry for the long post hope it will help ! ciao !
>
>
>
>
> // -- LCD ------------------------------------------------------------
>
>
> /*
> Instruction Code Description
> D7 D6 D5 D4 D3 D2 D1 D0
> Clear display 0 0 0 0 0 0 0 1 Clears display and returns cursor to the home position (address 0). 1.64mS
> Cursor home 0 0 0 0 0 0 1 * Returns cursor to home position (address 0). Also returns display being
> shifted to the original position. DDRAM contents remains unchanged. 1.64mS
> Entry mode set 0 0 0 0 0 1 I/D S Sets cursor move direction (I/D), specifies to shift the display (S).
> These operations are performed during data read/write. 40uS
> Display On/Off control 0 0 0 0 1 D C B Sets On/Off of all display (D), cursor On/Off (C) and blink of cursor
> position character (B). 40uS
> Cursor/display shift 0 0 0 1 S/C R/L * * Sets cursor-move or display-shift (S/C), shift direction (R/L). DDRAM
> contents remains unchanged. 40uS
> Function set 0 0 1 DL N F * * Sets interface data length (DL), number of display line (N) and character
> font(F). 40uS
> Set CGRAM address 0 1 CGRAM address Sets the CGRAM address. CGRAM data is sent and received after this
> setting. 40uS
> Set DDRAM address 1 DDRAM address Sets the DDRAM address. DDRAM data is sent and received after this
> setting. 40uS
>
> Read busy-flag and address counter 0 1 BF CGRAM / DDRAM address Reads Busy-flag (BF) indicating internal operation is being
> performed and reads CGRAM or DDRAM address counter contents (depending on previous instruction). 0uS
> Write to CGRAM or DDRAM 1 0 write data Writes data to CGRAM or DDRAM. 40uS
> Read from CGRAM or DDRAM 1 1 read data Reads data from CGRAM or DDRAM. 40uS
> Remarks:
>
> */
>
>
> // HD44780 Commandset
>
> // 01h Clear display
> #define LCD_CLR 0 // DB0: clear display
>
> // 02h or 03h Return cursor home
> #define LCD_HOME 1 // DB1: return to home position
>
> // 04h 05h 06h 07h Entry mode set
> #define LCD_ENTRY_MODE 2 // DB2: set entry mode
> #define LCD_ENTRY_INC 1 // DB1: increment
> #define LCD_ENTRY_SHIFT 0 // DB2: shift
>
> // 08h 09h 0Ah 0Bh 0Ch 0Dh 0Eh 0Fh Display/Cursor ON OFF
> #define LCD_ON_CTRL 3 // DB3: turn lcd/cursor on
> #define LCD_ON_DISPLAY 2 // DB2: turn display on
> #define LCD_ON_CURSOR 1 // DB1: turn cursor on
> #define LCD_ON_BLINK 0 // DB0: blinking cursor
>
> #define LCD_MOVE 4 // DB4: move cursor/display
> #define LCD_MOVE_DISP 3 // DB3: move display (0-> move cursor)
> #define LCD_MOVE_RIGHT 2 // DB2: move right (0-> left)
>
> #define LCD_FUNCTION 5 // DB5: function set
> #define LCD_FUNCTION_8BIT 4 // DB4: set 8BIT mode (0->4BIT mode)
> #define LCD_FUNCTION_2LINES 3 // DB3: two lines (0->one line)
> #define LCD_FUNCTION_RE 2 // DB2: KS0073 Controller: Extended Register
> #define LCD_FUNCTION_10DOTS 2 // DB2: 5x10 font (0->5x7 font)
> #define LCD_FUNCTION_DS 1 // DB1: DisplayShift / DotScroll
> #define LCD_FUNCTION_REV 0 // DB0: Reverse Display
>
> #define LCD_EXT 3 // DB3: Extended Register Set
> #define LCD_EXT_FONT 2 // DB2: Fontwidth: 5 / 6 Pixel
> #define LCD_EXT_INVCURS 1 // DB1: Normal / Inverted Cursor
> #define LCD_EXT_4LINES 0 // DB0: 1/2 Lines (normal) or 4Lines
>
> #define LCD_CGRAM 6 // DB6: set CG RAM address
>
> #define LCD_DDRAM 7 // DB7: set DD RAM address
> // reading:
> #define LCD_BUSY 7 // DB7: LCD is busy
>
>
>
> // Initializing the LCD
> // Some definitions first. As we find in the schematic, the LCD data port is connected to
> // the upper 4 bits of port D.
>
> #define LCD_DATA_DDR DDRD
> #define LCD_DATA_PORT PORTD
>
> // The two control lines are connected to bits 2 and 3 of port E.
>
> #define LCD_CTRL_DDR DDRE
> #define LCD_CTRL_PORT PORTE
> #define LCD_CTRL_E PE3
> #define LCD_CTRL_RS PE2
> #define LCD_CTRL_RW PE4
>
> // The LCD backlight is controlled by bit 6 on port B. (no backlight for now ...)
>
> // #define LCD_LIGHT_DDR DDRB
> // #define LCD_LIGHT_PORT PORTB
> // #define LCD_LIGHT_BIT PB6
>
> // Various delays
>
> #define LCD_PWRON_DELAY 10
> #define LCD_INIT_DELAY 4
> #define LCD_LONG_DELAY 2
> #define LCD_SHORT_DELAY 1
>
>
>
> // Controlling the LCD
> // The initialization routine already uses other subroutines to send data bytes and
> // instructions to the LCD controller. Remember, that we drive the LCD in 4 bit mode. A
> // special routine named LcdSendNibble will send the upper four bits of a character
> // variable to the LCD data port. It sets the data lines and toggles the enable line.
>
> static inline void LcdSendNibble(u_char nib)
> {
> outp((inp(LCD_DATA_PORT)& 0x0F) | (nib& 0xF0), LCD_DATA_PORT);
> sbi(LCD_CTRL_PORT, LCD_CTRL_E);
> asm volatile("nop\n\tnop");
> cbi(LCD_CTRL_PORT, LCD_CTRL_E);
> }
>
>
>
> // Another routine called LcdSendByte sends a complete byte to the LCD controller by
> // calling LcdSendNibble twice.
>
> static inline void LcdSendByte(u_char ch, u_char xt)
> {
> LcdSendNibble(ch& 0xF0);
> LcdSendNibble(ch<< 4);
> NutDelay(xt);
> }
>
>
>
> // Finally two additional routines are provided to either send an instruction or a data byte.
> // Note, that only instructions need a specific delay time.
>
> static void LcdWriteCmd(u_char cmd, u_char xt)
> {
> cbi(LCD_CTRL_PORT, LCD_CTRL_RS);
> LcdSendByte(cmd, xt);
> }
>
> void LcdWriteChar(u_char ch)
> {
> sbi(LCD_CTRL_PORT, LCD_CTRL_RS);
> LcdSendByte(ch,LCD_SHORT_DELAY);
> }
>
>
> void LcdWriteS(char *ch)
> {
> int i;
> char c;
>
> i=0;
> while((c=ch[i++])>0){
> LcdWriteChar(c);
> }
> }
>
>
> // One of the most often used instructions to be send to the display is the clear
> // command, which blanks the display. A special routine LcdClear will do this.
>
> void LcdClear(void)
> {
> LcdWriteCmd(LCD_HOME,LCD_LONG_DELAY);
> }
>
>
> // The initialization routine uses another command routine named LcdSwitch, which
> // switches on and off certain mode bits in the LCD controller.
>
> void LcdSwitch(u_char on, u_char off)
> {
> // switch_control |= on& LCD_SWITCH_ALL;
> // switch_control&= ~(off& LCD_SWITCH_ALL);
> // LcdWriteCmd(switch_control, LCD_SHORT_DELAY);
> }
>
>
> // When calling LcdWriteChar instead of LcdWriteCmd, the characters of the specified
> // codes are displayed and the cursor is automatically advanced to the next character
> // position. In addition to the normal 7 bit ASCII character set the controller can display
> // many other characters. It is even possible to define up to 8 custom characters, which
> // however isn't explained in this application note.
>
>
>
> // The LCD controller doesn't support cursor positioning on a specific column or row, but
> // requires a memory address. This is not a big deal on 2 line displays, but address
> // locations for the third and the second row depend on the number of columns being
> // displayed. On 4 line displays with 16 columns each, the values are:
>
> // #define LCD_ROW2_START 0x10
> // #define LCD_ROW3_START 0x50
> #define LCD_ROW2_START 0x14
> #define LCD_ROW3_START 0x54
>
>
> // Another routine called LcdSetCursor may be used to place the cursor to a specific
> // position.
>
> void LcdSetCursor(u_char row, u_char col)
> {
> u_char row_start[] = { 0x00, 0x40, LCD_ROW2_START, LCD_ROW3_START };
>
> LcdWriteCmd(0x80 | row_start[row& 0x03] | col, LCD_SHORT_DELAY);
> }
>
>
>
> // routine called LcdSetCursor may be used to place the cursor to a specific
> // position.
>
> void LcdWriteAt(u_char row, u_char col, char *ch)
> {
> LcdSetCursor(row,col);
> LcdWriteS(ch);
> }
>
>
>
> // A single routine is used to initialize all I/O lines and setup the LCD. Most notable is the
> // for loop somewhere in the middle of the routine. When the LCD is powered up, the
> // LCD controller will start in 8 bit mode. Switching it into 4 bit mode requires a specific
> // command sequence. The loop will send three nibbles of value 3, two of value 2 and
> // finally of value 8.
>
> void LcdInit(void)
> {
> u_char i;
>
>
> /*
> * Set LCD read write low.
> */
> cbi(LCD_CTRL_PORT, LCD_CTRL_RW);
> sbi(LCD_CTRL_DDR, LCD_CTRL_RW);
>
> /*
> * Set LCD register select low.
> */
> cbi(LCD_CTRL_PORT, LCD_CTRL_RS);
> sbi(LCD_CTRL_DDR, LCD_CTRL_RS);
>
> /*
> * Set LCD enable low.
> */
> cbi(LCD_CTRL_PORT, LCD_CTRL_E);
> sbi(LCD_CTRL_DDR, LCD_CTRL_E);
>
> /*
> * Set direction register of LCD data port.
> */
> sbi(LCD_DATA_DDR, 4);
> sbi(LCD_DATA_DDR, 5);
> sbi(LCD_DATA_DDR, 6);
> sbi(LCD_DATA_DDR, 7);
>
> /*
> * Initialize for 4-bit operation.
> */
> NutDelay(LCD_PWRON_DELAY);
> for(i = 0;i<3; i++){
> LcdSendNibble(0x30);
> NutDelay(LCD_INIT_DELAY);
> }
>
> LcdSendNibble(0x20);
> NutDelay(LCD_SHORT_DELAY);
>
> /*
> * 4-bit mode, 2/4 lines, 5x7 matrix.
> */
> LcdWriteCmd(0x28,LCD_SHORT_DELAY);
>
> /*
> * Switch display, cursor and cursor blinking off.
> */
> // LcdSwitch(0, LCD_SWITCH_ALL);
>
> /*
> * Clear display.
> */
> LcdClear();
>
> /*
> * Increment cursor when writing.
> */
> LcdWriteCmd((1<<LCD_ENTRY_MODE|1<<LCD_ENTRY_INC|0<<LCD_ENTRY_SHIFT),LCD_SHORT_DELAY);
>
> /*
> * Set cursor appearance
> */
> LcdWriteCmd((1<<LCD_ON_CTRL|1<<LCD_ON_DISPLAY|1<<LCD_ON_CURSOR|1<<LCD_ON_BLINK),LCD_SHORT_DELAY);
>
>
> /*
> * Lit LED and switch display on.
> */
> // sbi(LCD_LIGHT_DDR, LCD_LIGHT_BIT);
> // sbi(LCD_LIGHT_PORT, LCD_LIGHT_BIT);
> // LcdSwitch(LCD_SWITCH_DISPLAY, 0);
>
> }
>
>
> // -- END LCD --------------------------------------------------------
>
>
>
>
>
>
>
>
> --
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