Raspberry Pi ST7796 SPI Demo

demo.py

import time
import spidev
import RPi.GPIO as GPIO
from PIL import Image, ImageDraw, ImageFont

# --- 配置引脚 (BCM 编码) ---
DC_PIN = 24
RST_PIN = 25
BL_PIN = 17
SPI_BUS = 0
SPI_DEVICE = 0

# --- ST7796 初始化命令 ---
def init_display(spi):
    def send_cmd(cmd):
        GPIO.output(DC_PIN, GPIO.LOW)
        spi.writebytes([cmd])

    def send_data(data):
        GPIO.output(DC_PIN, GPIO.HIGH)
        spi.writebytes([data])

    # --- 硬件复位 ---
    GPIO.output(RST_PIN, GPIO.HIGH)
    time.sleep(0.01)
    GPIO.output(RST_PIN, GPIO.LOW)
    time.sleep(0.01)
    GPIO.output(RST_PIN, GPIO.HIGH)
    time.sleep(0.12)

    # --- 通用初始化 ---
    send_cmd(0x01)  # Software Reset
    time.sleep(0.12)

    send_cmd(0x11)  # Sleep Out
    time.sleep(0.12)

    send_cmd(0xF0)
    send_data(0xC3)
    send_cmd(0xF0)
    send_data(0x96)

    # ★★★ 竖屏 左转 90 度竖屏 ★★★
    send_cmd(0x36)  
    send_data(0x88)

    send_cmd(0x3A)
    send_data(0x55)  # 16bit

    send_cmd(0xB4)
    send_data(0x01)

    send_cmd(0xB7)
    send_data(0xC6)

    send_cmd(0xE8)
    send_data(0x40)
    send_data(0x8A)
    send_data(0x00)
    send_data(0x00)
    send_data(0x29)
    send_data(0x19)
    send_data(0xA5)
    send_data(0x33)

    send_cmd(0x29)  # Display ON
    time.sleep(0.05)


# --- 竖屏图像写入 ---
def display_image(spi, image):
    # ★★★ 竖屏分辨率（右转90度）★★★
    w, h = 320, 480  # 替换原480,320

    # 调整输出图像
    img = image.resize((w, h), Image.BICUBIC)
    img_raw = img.convert('RGB')
    pixels = list(img_raw.getdata())

    # 转换为 RGB565
    buffer = []
    for r, g, b in pixels:
        val = ((r & 0xF8) << 8) | ((g & 0xFC) << 3) | (b >> 3)
        buffer.append(val >> 8)
        buffer.append(val & 0xFF)

    # 设置地址窗口
    def cmd(c):
        GPIO.output(DC_PIN, GPIO.LOW)
        spi.writebytes([c])

    def data(arr):
        GPIO.output(DC_PIN, GPIO.HIGH)
        spi.writebytes(arr)

    # Column 地址（竖屏列范围：0~319）
    cmd(0x2A)
    data([0, 0, (w - 1) >> 8, (w - 1) & 0xFF])

    # Page 地址（竖屏行范围：0~479）
    cmd(0x2B)
    data([0, 0, (h - 1) >> 8, (h - 1) & 0xFF])

    # Memory Write
    cmd(0x2C)
    GPIO.output(DC_PIN, GPIO.HIGH)

    # 分块写入
    chunk = 4096
    for i in range(0, len(buffer), chunk):
        spi.writebytes(buffer[i:i + chunk])


# --- 主程序 ---
def main():
    # GPIO 初始化
    GPIO.setmode(GPIO.BCM)
    GPIO.setwarnings(False)
    GPIO.setup(DC_PIN, GPIO.OUT)
    GPIO.setup(RST_PIN, GPIO.OUT)
    GPIO.setup(BL_PIN, GPIO.OUT)
    GPIO.output(BL_PIN, GPIO.HIGH)

    # SPI 初始化
    spi = spidev.SpiDev()
    spi.open(SPI_BUS, SPI_DEVICE)
    spi.max_speed_hz = 40000000
    spi.mode = 0b00

    try:
        print("Initializing Display...")
        init_display(spi)

        print("Drawing Image...")

        # ★★★ 竖屏画布 320×480 ★★★
        image = Image.new("RGB", (320, 480), "#008080")
        draw = ImageDraw.Draw(image)

        # 配置参数
        block_size = 80  # 色块尺寸80×80
        cols = 4         # 每行4个色块（4×80=320）
        rows = 6         # 共6行（6×80=480）
        # 定义两个交替的色块颜色（可自行修改）
        color1 = (50, 150, 250)   # 浅蓝色
        color2 = (250, 100, 50)    # 橙红色
        # 字体配置（适配80×80色块的居中数字）
        try:
            font = ImageFont.truetype(
                "/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf", 40
            )
        except:
            font = ImageFont.load_default(size=40)

        # 循环绘制4列×6行=24个色块
        num = 1  # 数字从1开始
        for row in range(rows):
            for col in range(cols):
                # 计算当前色块的坐标（左上角/右下角）
                x0 = col * block_size
                y0 = row * block_size
                x1 = x0 + block_size
                y1 = y0 + block_size

                # 交替选择色块颜色（奇数数字用color1，偶数用color2）
                bg_color = color1 if (row + col) % 2 == 0 else color2

                # 绘制色块
                draw.rectangle((x0, y0, x1, y1), fill=bg_color)

                # 计算数字居中坐标（基于文字边界框）
                text = str(num)
                # 获取文字的宽高（bbox返回：左、上、右、下）
                bbox = draw.textbbox((0, 0), text, font=font)
                text_w = bbox[2] - bbox[0]
                text_h = bbox[3] - bbox[1]
                # 计算居中位置
                text_x = x0 + (block_size - text_w) // 2
                text_y = y0 + (block_size - text_h) // 2

                # 绘制数字（白色字体，对比明显）
                draw.text((text_x, text_y), text, fill=(255, 255, 255), font=font)

                # 数字自增
                num += 1

        # 显示绘制好的图像
        display_image(spi, image)
        print("Done!")

    except KeyboardInterrupt:
        GPIO.cleanup()
        spi.close()


if __name__ == "__main__":
    main()