Merge pull request #14 from Joe7M/master

IOIO: HD44780 example

Author: chrisws

ioio/samples/hd44780.bas

@@ -0,0 +1,225 @@
+' HD44780 - Text LCD
+' ==================
+'
+' This example demonstrates how to use the alphanumeric
+' dot matrix liquid crystal display HD44780.
+' 
+' Connect the LCD to the IOIO-OTG board:
+'
+' -------         ------                   1 (GND)
+'  IOIO  |       |HD44780                  |
+'  PIN 41|-------|11 (DB4)                ---
+'  PIN 42|-------|12 (DB5)               |   |
+'  PIN 43|-------|13 (DB6)               |10K|<---3 (VEE)
+'  PIN 44|-------|14 (DB7)               |   |
+'  GND   |-------| 5 (RW)                 --- 
+'  PIN 45|-------| 6 (E)                   |
+'  PIN 46|-------| 4 (RS)                  2 (VIN)
+'  GND   |-------| 1 (GND)
+'  5V    |-------| 2 (VIN)
+'--------         --------
+
+' A potentiometer needs to be connected to the display
+' to control the contrast of the display. If the display
+' has a background light, connect power according to the
+' data sheet to the pins 15 and 16.
+'
+' Code based on https://www.mikrocontroller.net/articles/AVR-GCC-Tutorial/LCD-Ansteuerung
+
+
+'#########################################################
+'# Constant definition                                   #
+'#########################################################
+
+const LCD_CLEAR_DISPLAY =       0x01
+const LCD_CURSOR_HOME =         0x02
+
+const LCD_SET_ENTRY =           0x04
+const LCD_ENTRY_DECREASE =      0x00
+const LCD_ENTRY_INCREASE =      0x02
+const LCD_ENTRY_NOSHIFT =       0x00
+const LCD_ENTRY_SHIFT =         0x01
+ 
+const LCD_SET_DISPLAY =         0x08
+const LCD_DISPLAY_OFF =         0x00
+const LCD_DISPLAY_ON =          0x04
+const LCD_CURSOR_OFF =          0x00
+const LCD_CURSOR_ON =           0x02
+const LCD_BLINKING_OFF =        0x00
+const LCD_BLINKING_ON =         0x01
+ 
+const LCD_SET_SHIFT =           0x10
+const LCD_CURSOR_MOVE =         0x00
+const LCD_DISPLAY_SHIFT =       0x08
+const LCD_SHIFT_LEFT =          0x00
+const LCD_SHIFT_RIGHT =         0x04
+ 
+const LCD_SET_FUNCTION =        0x20
+const LCD_FUNCTION_4BIT =       0x00
+const LCD_FUNCTION_8BIT =       0x10
+const LCD_FUNCTION_1LINE =      0x00
+const LCD_FUNCTION_2LINE =      0x08
+const LCD_FUNCTION_5X7 =        0x00
+const LCD_FUNCTION_5X10 =       0x04
+ 
+const LCD_SOFT_RESET =          0x30
+
+const LCD_SET_CGADR =           0x40
+ 
+const LCD_DDADR_LINE1 =         0x00
+const LCD_DDADR_LINE2 =         0x40
+const LCD_DDADR_LINE3 =         0x10
+const LCD_DDADR_LINE4 =         0x50
+ 
+const LCD_GC_CHAR0 =            0
+const LCD_GC_CHAR1 =            1
+const LCD_GC_CHAR2 =            2
+const LCD_GC_CHAR3 =            3
+const LCD_GC_CHAR4 =            4
+const LCD_GC_CHAR5 =            5
+const LCD_GC_CHAR6 =            6
+const LCD_GC_CHAR7 =            7
+ 
+const LCD_SET_DDADR =           0x80
+
+'#########################################################
+'# Main program                                          #
+'#########################################################
+
+import ioio
+
+Print "Connect to HD44780"
+RS  = ioio.openDigitalOutput(46)
+E   = ioio.openDigitalOutput(45)
+DB4 = ioio.openDigitalOutput(41)
+DB5 = ioio.openDigitalOutput(42)
+DB6 = ioio.openDigitalOutput(43)
+DB7 = ioio.openDigitalOutput(44)
+ioio.waitForConnect(10)
+Print "Connection established"
+
+
+Init()
+LCD_Write("  Hello  World")
+LCD_Locate(1,2)
+LCD_Write("-= SmallBASIC =-")
+print "Done"
+
+
+end
+
+'#########################################################
+'# Functions and subs                                    #
+'#########################################################
+
+sub Init()
+
+  RS.write(0)
+  E.write(0)
+  DB4.write(0)
+  DB5.write(0)
+  DB6.write(0)
+  DB7.write(0)
+
+  delay(50)
+
+  ' Send soft-reset 3 time to initialize LCD
+  Send4Bit(LCD_SOFT_RESET)
+  delay(5) 
+  SendEnable()
+  delay(1)
+  SendEnable()
+  delay(1)
+
+  ' Set 4-bit mode
+  Send4Bit(LCD_SET_FUNCTION BOR LCD_FUNCTION_4BIT)
+  delay(5)
+
+  ' 2 lines and 5x7 pixel in 4 bit mode
+  SendCommand(LCD_SET_FUNCTION BOR LCD_FUNCTION_4BIT BOR LCD_FUNCTION_2LINE BOR LCD_FUNCTION_5X7)
+  ' Display on, cursor off and blinking off
+  SendCommand(LCD_SET_DISPLAY BOR LCD_DISPLAY_ON BOR LCD_CURSOR_OFF BOR LCD_BLINKING_OFF)
+  ' Cursor increment no scrolling
+  SendCommand(LCD_SET_ENTRY BOR LCD_ENTRY_INCREASE BOR LCD_ENTRY_NOSHIFT )
+  
+  LCD_Cls()
+end
+
+sub LCD_Write(Text)
+  ' Write characters to lcd
+  local length, t
+  length = len(Text)
+  
+  for i = 1 to length
+    t = asc(mid(text, i, 1))
+    SendData(t)
+  next
+end
+
+sub LCD_Cls()
+  SendCommand(LCD_CLEAR_DISPLAY)
+  SendCommand(LCD_CURSOR_HOME)
+end
+
+sub LCD_Off()
+  SendCommand(LCD_SET_DISPLAY BOR LCD_DISPLAY_OFF)
+end
+
+sub LCD_On()
+  SendCommand(LCD_SET_DISPLAY BOR LCD_DISPLAY_ON)
+end
+
+sub LCD_Locate(x, y)
+  local dat
+
+  if(x < 1) then x == 1
+  
+  select case y
+    case 1     ' 1. line
+      dat = LCD_SET_DDADR + LCD_DDADR_LINE1 + x - 1
+    case 2     ' 2. line
+      dat = LCD_SET_DDADR + LCD_DDADR_LINE2 + x - 1
+    case 3     ' 3. line
+      dat = LCD_SET_DDADR + LCD_DDADR_LINE3 + x - 1
+    case 4     ' 4. line
+      dat = LCD_SET_DDADR + LCD_DDADR_LINE4 + x - 1
+    case else
+      return
+  end select
+
+  SendCommand(dat)
+end
+
+sub SendCommand(cmd)
+  RS.write(0)
+  SendByte(cmd)
+end
+
+sub SendData(dat)
+  RS.write(1)
+  SendByte(dat)
+end
+
+sub SendEnable()
+  E.write(1)
+  delay(1)
+  E.write(0)
+  delay(1)
+end
+
+sub SendByte(byte)
+  Send4Bit(byte)          ' Send high bits first
+  Send4Bit(byte lshift 4) ' Send low bits
+end
+
+sub Send4Bit(byte)
+  DB7.write(GetBit(byte, 7))
+  DB6.write(GetBit(byte, 6))
+  DB5.write(GetBit(byte, 5))
+  DB4.write(GetBit(byte, 4))
+  SendEnable()  
+end
+
+func GetBit(value, bit)
+  return (value rshift bit) BAND 1
+end