# code translated by doubao ai from machine import Pin, SPI import time class LCD_12864_ST7920(): def __init__(self, a_spi, cs_pin): """ see README.md """ self.spi = a_spi self.cs = Pin(cs_pin, Pin.OUT) self.cs.low() # LCD parameters self.width = 128 self.height = 64 # Frame buffer (1024 bytes, initialized to 0) self.frame_buffer = bytearray(1024) # Initialize LCD self.initialize() def _send_byte(self, eight_bits): self.spi.write(eight_bits) def write_command(self, command): self.cs.high() # CS/RS high for command self._send_byte(0xF8) self._send_byte(command & 0xF0) # High 4 bits self._send_byte((command << 4) & 0xF0) # Low 4 bits time.sleep_us(100) # Short delay (faster than ms for SPI) self.cs.low() def write_data(self, data): self.cs.high() # CS/RS high for data self._send_byte(0xFA) self._send_byte(data & 0xF0) # High 4 bits self._send_byte((data << 4) & 0xF0) # Low 4 bits time.sleep_us(100) self.cs.low() def initialize(self): # Reset sequence with proper timing time.sleep_ms(100) # Basic instruction set self.write_command(0x30) time.sleep_ms(20) # Display on, cursor off self.write_command(0x0C) time.sleep_ms(20) # Clear text screen self.write_command(0x01) time.sleep_ms(200) # Enable graphic mode self.write_command(0x34) time.sleep_ms(20) self.write_command(0x36) time.sleep_ms(20) self.write_command(0x30) def clear_text_screen(self): self.write_command(0x01) time.sleep_ms(10) def clear_graphic_screen(self): # Clear frame buffer for i in range(1024): self.frame_buffer[i] = 0 # Clear physical LCD self.write_command(0x34) # Extended instruction set for y_pair in range(32): for x_byte in range(16): self.write_command(0x80 + y_pair) self.write_command(0x80 + x_byte) self.write_data(0x00) self.write_data(0x00) self.write_command(0x36) # Graphic display on self.write_command(0x30) # Basic instruction set def print_string(self, y, x, text): if y == 0: self.write_command(0x80 + x) elif y == 1: self.write_command(0x90 + x) elif y == 2: self.write_command(0x88 + x) elif y == 3: self.write_command(0x98 + x) for char in text: self.write_data(ord(char)) time.sleep_us(100) def draw_pixel(self, y, x, value): """0=off, 1=on""" # Coordinate validation if x < 0 or x >= self.width or y < 0 or y >= self.height: return # Calculate pixel position in frame buffer x_byte = x // 16 x_bit = x % 16 y_screen = y // 32 # 0=upper, 1=lower y_line = y % 32 # Calculate byte index base = y_screen * 32 * 16 word_offset = y_line * 16 + x_byte * 2 byte_index = base + word_offset # Update frame buffer if x_bit < 8: mask = 1 << (7 - x_bit) if value == 1: self.frame_buffer[byte_index] |= mask else: self.frame_buffer[byte_index] &= ~mask else: mask = 1 << (15 - x_bit) if value == 1: self.frame_buffer[byte_index + 1] |= mask else: self.frame_buffer[byte_index + 1] &= ~mask def update_graphic_screen(self): """must call this function after draw_point()""" temp_idx = 0 self.write_command(0x34) # Extended instruction set self.write_command(0x36) # Graphic display on # Upper screen (y=0~31) for y_line in range(32): self.write_command(0x80 | y_line) self.write_command(0x80) # Horizontal start (upper) for x_byte in range(8): self.write_data(self.frame_buffer[temp_idx]) temp_idx += 1 self.write_data(self.frame_buffer[temp_idx]) temp_idx += 1 # Lower screen (y=32~63) for y_line in range(32): self.write_command(0x80 | y_line) self.write_command(0x88) # Horizontal start (lower) for x_byte in range(8): self.write_data(self.frame_buffer[temp_idx]) temp_idx += 1 self.write_data(self.frame_buffer[temp_idx]) temp_idx += 1 self.write_command(0x30) # Back to basic instruction set def draw_pixel_directly(self, y, x, value): """Draw pixel directly to LCD (bypasses full buffer update)""" if x < 0 or x >= self.width or y < 0 or y >= self.height: return # Calculate position x_byte = x // 16 x_bit = x % 16 y_screen = y // 32 y_line = y % 32 # Calculate byte index base = y_screen * 32 * 16 word_offset = y_line * 16 + x_byte * 2 byte_index = base + word_offset # Get current bytes high_byte = self.frame_buffer[byte_index] low_byte = self.frame_buffer[byte_index + 1] # Update bytes if x_bit < 8: mask = 1 << (7 - x_bit) if value == 1: high_byte |= mask else: high_byte &= ~mask else: mask = 1 << (15 - x_bit) if value == 1: low_byte |= mask else: low_byte &= ~mask # Save back to buffer self.frame_buffer[byte_index] = high_byte self.frame_buffer[byte_index + 1] = low_byte # Write directly to LCD self.write_command(0x34) self.write_command(0x36) self.write_command(0x80 | y_line) self.write_command(0x80 + x_byte + (8 * y_screen)) self.write_data(high_byte) self.write_data(low_byte) self.write_command(0x30) if __name__ == "__main__": # SPI Configuration (Pico Hardware SPI) TFT_CLK_PIN = 2 # E -> SCK TFT_MOSI_PIN = 3 # RW -> MOSI TFT_MISO_PIN = 4 # Not used (ST7920 is write-only) TFT_CS_PIN = 5 # RS -> CS baudrate = 10000000 # 10MHz max for Pico SPI # Create hardware SPI instance # Note: Pico SPI write() requires bytearray, so we wrap it for compatibility class HardwareSPIWrapper: def __init__(self, spi): self.spi = spi def write(self, data): """Wrapper to match Simple_Output_Soft_SPI write() interface""" if isinstance(data, int): self.spi.write(bytearray([data])) else: self.spi.write(bytearray(data)) # Initialize SPI spi_hw = SPI(0, baudrate=baudrate, sck=Pin(TFT_CLK_PIN), mosi=Pin(TFT_MOSI_PIN), miso=Pin(TFT_MISO_PIN)) spi_wrapper = HardwareSPIWrapper(spi_hw) # Create LCD instance lcd = LCD_12864_ST7920(spi_wrapper, TFT_CS_PIN) # Test the LCD (same functionality as original setup) def test_lcd(): # Clear screens lcd.clear_text_screen() lcd.clear_graphic_screen() # Print text lcd.print_string(0, 0, "Hi! (SPI 10MHz)") # Draw 8x8 square for y in range(28, 36): for x in range(60, 68): lcd.draw_pixel(y, x, 1) lcd.update_graphic_screen() # Draw single pixel directly lcd.draw_pixel_directly(22, 98, 1) print("LCD test completed!") test_lcd()