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module:micropython:esp32lcdisplayi2c:esp32lcdisplayi2c [2021/12/16 15:05] – [Links] omdevelopmodule:micropython:esp32lcdisplayi2c:esp32lcdisplayi2c [2022/09/13 11:58] (current) – external edit 127.0.0.1
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 ===== Übersicht ===== ===== Übersicht =====
 +  * Esp32-Ansteuerung eines LCDisplays mit I2C-Interface(PCF8574)
 +  * das LCDisplay besitzt 4 Zeilen und 20 Spalten
  
 ==== Links ==== ==== Links ====
   * [[https://github.com/dhylands/python_lcd | dhylands-python_lcd]]   * [[https://github.com/dhylands/python_lcd | dhylands-python_lcd]]
  
-==== ==== +==== Quell-Code==== 
- +**Main-Program: CheckEsp32LCDisplayI2C.py**
-**Module**+
 <code python> <code python>
 # #
Line 65: Line 66:
 </code> </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> 
 + 
 +**Library-Module: LCDisplay.py (Basic-Class)**
 <code python> <code python>
 """Provides an API for talking to HD44780 compatible character LCDs.""" """Provides an API for talking to HD44780 compatible character LCDs."""
Line 213: Line 287:
     #     #
 # #
-</code> 
- 
-**Module** 
-<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> </code>
  
module/micropython/esp32lcdisplayi2c/esp32lcdisplayi2c.1639663546.txt.gz · Last modified: 2021/12/16 16:05 (external edit)