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--- module:micropython:esp32lcdisplayi2c:esp32lcdisplayi2c [2021/12/16 15:04] – [Entwicklung] omdevelop
+++ module:micropython:esp32lcdisplayi2c:esp32lcdisplayi2c [2022/09/13 11:58] (current) – external edit 127.0.0.1
@@ Line 9: / Line 9: @@
 ===== Übersicht =====
+  * Esp32-Ansteuerung eines LCDisplays mit I2C-Interface(PCF8574)
+  * das LCDisplay besitzt 4 Zeilen und 20 Spalten
 ==== Links ====
   * [[https://github.com/dhylands/python_lcd | dhylands-python_lcd]]
-==== ====
+==== Quell-Code====
+**Main-Program: CheckEsp32LCDisplayI2C.py**
-**Module**
 <code python>
+#
+import time
+import machine
+import LCDisplayI2C
+#
+I2CADDRESS_LCDISPLAY_T  = 0x27
+I2CADDRESS_LCDISPLAY_A  = 0x3F
+#
+LCDISPLAY_COUNT_ROWS    = 4
+LCDISPLAY_COUNT_COLUMNS = 20
+#
+def TestLoop():
+    for S in range(0, 10):
+        LCDisplay.MoveTo(0, 0)
+        LCDisplay.PutText('********************')
+        LCDisplay.MoveTo(1, 0)
+        LCDisplay.PutText('* Esp32LCDisplay   *')
+        LCDisplay.MoveTo(2, 0)
+        LCDisplay.PutText('* Version 01V01    *')
+        LCDisplay.MoveTo(3, 0)
+        LCDisplay.PutText('********************')
+        time.sleep_ms(2000)
+        LCDisplay.Clear()
+        for P in range(0, 30):
+            LCDisplay.MoveTo(0, 0)
+            LCDisplay.PutText('Line0[{}]'.format(time.ticks_ms()))
+            LCDisplay.MoveTo(1, 0)
+            LCDisplay.PutText('Line1[{}]'.format(time.ticks_ms()))
+            LCDisplay.MoveTo(2, 0)
+            LCDisplay.PutText('Line2[{}]'.format(time.ticks_ms()))
+            LCDisplay.MoveTo(3, 0)
+            LCDisplay.PutText('Line3[{}]'.format(time.ticks_ms()))
+    #
+#-------------------------------------------------------------
+if '__main__' == __name__:
+    print('*** CheckEsp32LCDisplayI2C: begin')
+    #
+    I2CDisplay = machine.SoftI2C(scl=machine.Pin(22), sda=machine.Pin(21), freq=2000000)
+    LCDisplay = LCDisplayI2C.CLCDisplayI2C(I2CDisplay, I2CADDRESS_LCDISPLAY_T, \
+                                           LCDISPLAY_COUNT_ROWS, LCDISPLAY_COUNT_COLUMNS)
+    #
+    TestLoop()
+    #
+    print('*** CheckEsp32LCDisplayI2C: end')
+    #
+#
 </code>
-**Module**
+**Library-Module: LCDisplayI2C.py (derived from Basic-Class)**
 <code python>
+#
+"""Implements a HD44780 character LCD connected via PCF8574 on I2C"""
+#
+from LCDisplay import CLCDisplay
+from time import sleep_ms
+#
+# The PCF8574 has a jumper selectable address: 0x20 - 0x27
+DEFAULT_I2C_ADDR = 0x27
+#
+MASK_RS = 0x01
+MASK_RW = 0x02
+MASK_E = 0x04
+SHIFT_BACKLIGHT = 3
+SHIFT_DATA = 4
+#
+class CLCDisplayI2C(CLCDisplay):
+    #
+    def __init__(self, i2c, i2caddress, countrows, countcolumns):
+        self.I2C = i2c
+        self.I2CAddress = i2caddress
+        self.I2C.writeto(self.I2CAddress, bytearray([0]))
+        sleep_ms(20)   # Allow LCD time to powerup
+        # Send reset 3 times
+        self.hal_write_init_nibble(self.LCD_FUNCTION_RESET)
+        sleep_ms(5)    # need to delay at least 4.1 msec
+        self.hal_write_init_nibble(self.LCD_FUNCTION_RESET)
+        sleep_ms(1)
+        self.hal_write_init_nibble(self.LCD_FUNCTION_RESET)
+        sleep_ms(1)
+        # Put LCD into 4 bit mode
+        self.hal_write_init_nibble(self.LCD_FUNCTION)
+        sleep_ms(1)
+        CLCDisplay.__init__(self, countrows, countcolumns)
+        cmd = self.LCD_FUNCTION
+        if countrows > 1:
+            cmd |= self.LCD_FUNCTION_2LINES
+        self.hal_write_command(cmd)
+    #
+    def hal_write_init_nibble(self, nibble):
+        byte = ((nibble >> 4) & 0x0f) << SHIFT_DATA
+        self.I2C.writeto(self.I2CAddress, bytearray([byte | MASK_E]))
+        self.I2C.writeto(self.I2CAddress, bytearray([byte]))
+    #
+    def hal_backlight_on(self):
+        self.I2C.writeto(self.I2CAddress, bytearray([1 << SHIFT_BACKLIGHT]))
+    #
+    def hal_backlight_off(self):
+        self.I2C.writeto(self.I2CAddress, bytearray([0]))
+    #
+    def hal_write_command(self, cmd):
+        """Data is latched on the falling edge of E."""
+        byte = ((self.Backlight << SHIFT_BACKLIGHT) | (((cmd >> 4) & 0x0f) << SHIFT_DATA))
+        self.I2C.writeto(self.I2CAddress, bytearray([byte | MASK_E]))
+        self.I2C.writeto(self.I2CAddress, bytearray([byte]))
+        byte = ((self.Backlight << SHIFT_BACKLIGHT) | ((cmd & 0x0f) << SHIFT_DATA))
+        self.I2C.writeto(self.I2CAddress, bytearray([byte | MASK_E]))
+        self.I2C.writeto(self.I2CAddress, bytearray([byte]))
+        if cmd <= 3: # The home and clear commands require a worst case delay of 4.1 msec
+            sleep_ms(5)
+    #
+    def hal_write_data(self, data):
+        byte = (MASK_RS | (self.Backlight << SHIFT_BACKLIGHT) | (((data >> 4) & 0x0f) << SHIFT_DATA))
+        self.I2C.writeto(self.I2CAddress, bytearray([byte | MASK_E]))
+        self.I2C.writeto(self.I2CAddress, bytearray([byte]))
+        byte = (MASK_RS | (self.Backlight << SHIFT_BACKLIGHT) | ((data & 0x0f) << SHIFT_DATA))
+        self.I2C.writeto(self.I2CAddress, bytearray([byte | MASK_E]))
+        self.I2C.writeto(self.I2CAddress, bytearray([byte]))
+    #
+#
 </code>
-**Module**
+**Library-Module: LCDisplay.py (Basic-Class)**
 <code python>
+"""Provides an API for talking to HD44780 compatible character LCDs."""
+#
+import time
+#
+class CLCDisplay:
+    # HD44780 LCD controller command set
+    LCD_CLR = 0x01              # DB0: clear display
+    LCD_HOME = 0x02             # DB1: return to home position
+    #
+    LCD_ENTRY_MODE = 0x04       # DB2: set entry mode
+    LCD_ENTRY_INC = 0x02        # --DB1: increment
+    LCD_ENTRY_SHIFT = 0x01      # --DB0: shift
+    #
+    LCD_ON_CTRL = 0x08          # DB3: turn lcd/cursor on
+    LCD_ON_DISPLAY = 0x04       # --DB2: turn display on
+    LCD_ON_CURSOR = 0x02        # --DB1: turn cursor on
+    LCD_ON_BLINK = 0x01         # --DB0: blinking cursor
+    #
+    LCD_MOVE = 0x10             # DB4: move cursor/display
+    LCD_MOVE_DISP = 0x08        # --DB3: move display (0-> move cursor)
+    LCD_MOVE_RIGHT = 0x04       # --DB2: move right (0-> left)
+    #
+    LCD_FUNCTION = 0x20         # DB5: function set
+    LCD_FUNCTION_8BIT = 0x10    # --DB4: set 8BIT mode (0->4BIT mode)
+    LCD_FUNCTION_2LINES = 0x08  # --DB3: two lines (0->one line)
+    LCD_FUNCTION_10DOTS = 0x04  # --DB2: 5x10 font (0->5x7 font)
+    LCD_FUNCTION_RESET = 0x30   # See "Initializing by Instruction" section
+    #
+    LCD_CGRAM = 0x40            # DB6: set CG RAM address
+    LCD_DDRAM = 0x80            # DB7: set DD RAM address
+    #
+    LCD_RS_CMD = 0
+    LCD_RS_DATA = 1
+    #
+    LCD_RW_WRITE = 0
+    LCD_RW_READ = 1
+    #
+    def __init__(self, num_lines, num_columns):
+        self.num_lines = num_lines
+        if self.num_lines > 4:
+            self.num_lines = 4
+        self.num_columns = num_columns
+        if self.num_columns > 40:
+            self.num_columns = 40
+        self.CursorY = 0
+        self.CursorX = 0
+        self.ImpliedNewline = False
+        self.Backlight = True
+        self.DisplayOff()
+        self.BacklightOn()
+        self.Clear()
+        self.hal_write_command(self.LCD_ENTRY_MODE | self.LCD_ENTRY_INC)
+        self.HideCursor()
+        self.DisplayOn()
+    #
+    def Clear(self):
+        self.hal_write_command(self.LCD_CLR)
+        self.hal_write_command(self.LCD_HOME)
+        self.CursorY = 0
+        self.CursorX = 0
+    #
+    def ShowCursor(self):
+        self.hal_write_command(self.LCD_ON_CTRL | self.LCD_ON_DISPLAY |
+                               self.LCD_ON_CURSOR)
+    #
+    def HideCursor(self):
+        self.hal_write_command(self.LCD_ON_CTRL | self.LCD_ON_DISPLAY)
+    #
+    def BlinkCursorOn(self):
+        self.hal_write_command(self.LCD_ON_CTRL | self.LCD_ON_DISPLAY |
+                               self.LCD_ON_CURSOR | self.LCD_ON_BLINK)
+    #
+    def BlinkCursorOff(self):
+        self.hal_write_command(self.LCD_ON_CTRL | self.LCD_ON_DISPLAY |
+                               self.LCD_ON_CURSOR)
+    #
+    def DisplayOn(self):
+        self.hal_write_command(self.LCD_ON_CTRL | self.LCD_ON_DISPLAY)
+    #
+    def DisplayOff(self):
+        self.hal_write_command(self.LCD_ON_CTRL)
+    #
+    def BacklightOn(self):
+        self.backlight = True
+        self.hal_backlight_on()
+    #
+    def BacklightOff(self):
+        self.backlight = False
+        self.hal_backlight_off()
+    #
+    def MoveTo(self, cursory, cursorx):
+        self.CursorY = cursory
+        self.CursorX = cursorx
+        Address = cursorx & 0x3f
+        if cursory & 1:
+            Address += 0x40    # Lines 1 & 3 add 0x40
+        if cursory & 2:     # Lines 2 & 3 add number of columns
+            Address += self.num_columns
+        self.hal_write_command(self.LCD_DDRAM | Address)
+    #
+    def PutCharacter(self, character):
+        if character == '\n':
+            if self.implied_newline:
+                self.implied_newline = False
+            else:
+                self.CursorX = self.num_columns
+        else:
+            self.hal_write_data(ord(character))
+            self.CursorX += 1
+        if self.CursorX >= self.num_columns:
+            self.CursorX = 0
+            self.CursorY += 1
+            self.implied_newline = (character != '\n')
+        if self.CursorY >= self.num_lines:
+            self.CursorY = 0
+        self.MoveTo(self.CursorY, self.CursorX)
+    #
+    def PutText(self, text):
+        for C in text:
+            self.PutCharacter(C)
+    #
+    def custom_char(self, location, charmap):
+        location &= 0x7
+        self.hal_write_command(self.LCD_CGRAM | (location << 3))
+        self.hal_sleep_us(40)
+        for i in range(8):
+            self.hal_write_data(charmap[i])
+            self.hal_sleep_us(40)
+        self.MoveTo(self.cursor_y, self.cursor_x)
+    #
+    def hal_backlight_on(self):
+        pass
+    #
+    def hal_backlight_off(self):
+        pass
+    #
+    def hal_write_command(self, cmd):
+        raise NotImplementedError
+    #
+    def hal_write_data(self, data):
+        raise NotImplementedError
+    #
+    def hal_sleep_us(self, usecs):
+        time.sleep_us(usecs)
+    #
+#
 </code>
-**Module**
-<code python>
-</code>
-**Module**
-<code python>
-</code>
-**Module**
-<code python>
-</code>