-- ------------------------------------------------------
-- Title: Output library to LCD KTM-S1201 lcd_ktms1201.jal
--
-- Author: Alexis Klyuev, RA1CAC, Copyright (c) 2014, all rights reserved.
--
-- Adapted-by:
--
-- Compiler: 2.4l
--
-- Description:
-- Библиотека вывода на дисплей LCD KTM-S1201
-- для Microchip PIC16f6xxa.
--
-- Sources:
--
-- Notes:
--  File creation date/time: 18 May 2014 00:53:00 MSK.
--
-- ------------------------------------------------------
--
--------------------------------------------------------------------------------
-- You may want to change the selected pin:
--	LCD KTM-S1201
-- alias LCD_SCK is pin_B0
-- pin_B0_direction = output
-- alias LCD_SI  is pin_B1
-- pin_B1_direction = output
-- alias LCD_CS  is pin_B2
-- pin_B2_direction = output
-- alias LCD_CD  is pin_B3
-- pin_B3_direction = output
--------------------------------------------------------------------------------
const byte lcd_CMD           = 1
const byte lcd_DATA          = 0
const byte lcd_BLINK_OFF     = 0x18
const byte lcd_BLINK_ON_SLOW = 0x1a
const byte lcd_BLINK_ON_FAST = 0x1b
const byte lcd_SPACE         = 0x0f
const byte lcd_MINUS         = 0x0a
const byte lcd_DOT           = 0x2e
const dword c10_000_000      = 10_000_000
const dword c1_000_000       = 1_000_000
const dword c100_000         = 100_000
const dword c10_000          = 10_000
const dword c1_000           = 1_000
const dword c100             = 100
const word  c10              = 10


const byte ini_buf[6] =
{ 0x40, 	-- mode set
	0x30,		-- use unsynchronized transfer
	0x18,		-- blink off
	0x11,		-- display on
	0x15,		-- segment decoder on
	0x20		-- clear data memory
}

--var volatile byte freq_str[13] --= {1,2,3,lcd_DOT,4,5,6,7,8,9,lcd_SPACE,1,lcd_MINUS}
var volatile byte decimal[4] = { 0x14, 0xe0, 0xb8, 0x15 }

;-------------------------------------------------------------------
;  lcd_write(...)
;
;  Note: /CS must be set before calling this function, and
;  reset afterwards (because its the release of /CS that makes the
;  LCD update its memory).
;-------------------------------------------------------------------
procedure lcd_write(byte in buffer[], byte in cnt, byte in cmd) is
  var byte i
  var byte c

	if(cmd != 0x00) then
		LCD_CD = lcd_CMD
	else
	  LCD_CD = lcd_DATA
	end if

  for cnt using i loop
    c = buffer[i]
    if (c != ".") then
  	  for 8 loop
		    LCD_SCK = off
		    if ((c & 0x80) != 0x00) then
	  		  LCD_SI = on
   		  else
			    LCD_SI = off
        end if
	    	LCD_SCK = on
    		c = c << 1
        _usec_delay(20)
      end loop
    end if
	end loop
end procedure

;-------------------------------------------------------------------
;  lcd_init()
;
;  Initialize the KTM-S1201: segment decoder on, unsynchronized
;  transfer mode.
;-------------------------------------------------------------------
procedure lcd_init() is
  LCD_CS = low
; wait a few us for /BUSY to exit high impedance state
  _usec_delay(2000)
  lcd_write(ini_buf, 6, 1)
  LCD_CS = high
end procedure

;--------------------------------------------------------------------------------
; lcd_dword_to_str(dword in freq, sword in delta, byte in str[], bit in rit_on)
; freq - source value
; delta -  RX delta +-
; str[] - output buffer
; rit_on - rx delta 1 = on, 0 = off
;--------------------------------------------------------------------------------
procedure lcd_dword_to_str(dword in freq, sword in delta, byte in str[], bit in rit_on) is
  var byte i,j,d
  var word udelta
  var dword divider = c10_000_000
  
  for 12 using i loop
    str[i] = lcd_SPACE
  end loop

  j = 7
  for 7 loop
    d = byte(freq / divider)
    if ((d != 0) | (str[j+1] != lcd_SPACE)) then
      str[j] = d
    end if
    freq = freq % divider
    divider = divider / 10
    j = j - 1
  end loop

  str[0] = byte(freq)

  if rit_on then
    if delta < 0 then
      str[11] = lcd_MINUS
      udelta = word(delta * -1)
    else
      udelta = word(delta)
    end if
    str[10] = byte(udelta / c100)
    udelta = word(udelta % c100)
    str[9] = byte(udelta / c10)
    udelta = word(udelta % c10)
    str[8] = byte(udelta)
  end if

end procedure
--------------------------------------------------------------------------------


;-------------------------------------------------------------------
;  lcd_puts(...)
;
;  Send a string to the KTM-S1201. Allowed characters are
;  0x00 - 0x09 : numeric digits
;  lcd_SPACE   : blank
;  lcd_DOT     : decimal point
;  lcd_MINUS   : minus sign
;
;  position = starting position relative to the left hand side,
;  which is 0.
;
;  Limitation: only one decimal point is supported in the input
;  string. If you need more decimal points, use
;  LCD_insert_decimal().
;-------------------------------------------------------------------*/
procedure lcd_puts(byte in buffer[], sbyte in position ) is
  var byte ucDecoderOn[1] = {0x15}
  var byte ucClear[1] = {0x20}
  var byte ucBuffer[2]
  var byte i, n, pos, chars=0

  LCD_CS = low
; wait a few us for /BUSY to exit high impedance state
  _usec_delay(2000)

  lcd_write( ucClear, 1, lcd_CMD )     ; clear memory
  lcd_write( ucDecoderOn, 1, lcd_CMD ) ; decoder on

  n = byte(count(buffer))
  for n using i loop
    if (buffer[i] != "." ) then
      chars = chars + 1
    end if
  end loop

  pos = 12 - ( position + chars )
  if (( position + chars ) == 0) then
    pos = 11
  elsif (( position + chars ) > 12) then
    pos = 0
  end if

  ucBuffer[0] = 0xe0 | (2 * pos)
  lcd_write( ucBuffer, 1, lcd_CMD)
  lcd_write(buffer, 13, lcd_DATA)      ; out data

  for 13 using i loop
    if ((buffer[i] == lcd_DOT) & (i >= position))then
      decimal[1] = 0xE0 + (2 * (i-position))
      lcd_write(decimal, 4, lcd_CMD)
	  end if
  end loop
  LCD_CS = high
end procedure

;-------------------------------------------------------------------
;  LCD_blink(...)
;
;  Turn blinking on or off. Use BLINK_ defines for parameter.
;
;  Observation: SLOW blinks on and off in approximately 1 second
;  			   FAST blinks twice the speed as slow
;			   When blinking, some segments stay on all the time!
;					why? (looks like crap).
;-------------------------------------------------------------------
procedure lcd_blink (byte in blink) is
  var byte ucBuffer[1]
  LCD_CS = low
; wait a few us for /BUSY to exit high impedance state
  _usec_delay(2000)
  ucBuffer[0] = blink
  lcd_write( ucBuffer, 1, lcd_CMD);
  LCD_CS = high
end procedure

;-------------------------------------------------------------------
;  LCD_insert_decimal(...)
;
;  Insert a decimal point at the position specified (relative
;  to the left hand side).
;-------------------------------------------------------------------
procedure lcd_insert_decimal( byte in position ) is
;  static unsigned char  ucDecimal[4] = { 0x14, 0xe0, 0xb8, 0x15 };
  var byte pos;

  if ( position > 12 ) then
    position = 12
  end if
;  if ( position < 0 )  position = 0

  LCD_CS = low
; wait a few us for /BUSY to exit high impedance state
  _usec_delay(2000)

  pos = 12 - position;
  if ( pos > 12 ) then
    pos = 12
	end if
;  if ( pos < 0 ) pos = 0;
  decimal[1] = 0xe0 | ( 2 * pos );
  lcd_write(decimal, 4, lcd_CMD);
  LCD_CS = high
end procedure

-------------------------------------------
;procedure lcd_display_number(dword in number, byte in pos) is
;  lcd_write(freq_str, 12, 0)
;end procedure
-------------------------------------------