• 物联网开发笔记（48）- 使用Micropython开发ESP32开发板之控制OLED ssd1306屏幕

    一、目的

            这一节我们学习如何使用我们的ESP32开发板来控制OLED ssd1306屏幕，此处使用的是I2C协议，大家可自行百度学习一下I2C。

    二、环境

            ESP32 + OLED ssd1306屏幕 + Thonny IDE（或者WOKWI在线仿真） + 几根杜邦线

    本次使用在线仿真，笔者太穷了，写了那么多，也没人打赏，买不起设备了！！！

     接线方法：

     WOKWI在线仿真地址，国外网站，速度较慢：

    Wokwi - Online Arduino and ESP32 Simulator

    关于这个屏幕的具体介绍参考如下地址：

    board-ssd1306 Reference | Wokwi Docs

    三、代码

    屏幕驱动芯片：

    1. #MicroPython SSD1306 OLED driver, I2C and SPI interfaces created by Adafruit
    2.  
    3. import time
    4. import framebuf
    5.  
    6. # register definitions
    7. SET_CONTRAST        = const(0x81)
    8. SET_ENTIRE_ON       = const(0xa4)
    9. SET_NORM_INV        = const(0xa6)
    10. SET_DISP            = const(0xae)
    11. SET_MEM_ADDR        = const(0x20)
    12. SET_COL_ADDR        = const(0x21)
    13. SET_PAGE_ADDR       = const(0x22)
    14. SET_DISP_START_LINE = const(0x40)
    15. SET_SEG_REMAP       = const(0xa0)
    16. SET_MUX_RATIO       = const(0xa8)
    17. SET_COM_OUT_DIR     = const(0xc0)
    18. SET_DISP_OFFSET     = const(0xd3)
    19. SET_COM_PIN_CFG     = const(0xda)
    20. SET_DISP_CLK_DIV    = const(0xd5)
    21. SET_PRECHARGE       = const(0xd9)
    22. SET_VCOM_DESEL      = const(0xdb)
    23. SET_CHARGE_PUMP     = const(0x8d)
    24.  
    25.  
    26. class SSD1306:
    27.     def __init__(self, width, height, external_vcc):
    28.         self.width = width
    29.         self.height = height
    30.         self.external_vcc = external_vcc
    31.         self.pages = self.height // 8
    32.         # Note the subclass must initialize self.framebuf to a framebuffer.
    33.         # This is necessary because the underlying data buffer is different
    34.         # between I2C and SPI implementations (I2C needs an extra byte).
    35.         self.poweron()
    36.         self.init_display()
    37.  
    38.     def init_display(self):
    39.         for cmd in (
    40.             SET_DISP | 0x00, # off
    41.             # address setting
    42.             SET_MEM_ADDR, 0x00, # horizontal
    43.             # resolution and layout
    44.             SET_DISP_START_LINE | 0x00,
    45.             SET_SEG_REMAP | 0x01, # column addr 127 mapped to SEG0
    46.             SET_MUX_RATIO, self.height - 1,
    47.             SET_COM_OUT_DIR | 0x08, # scan from COM[N] to COM0
    48.             SET_DISP_OFFSET, 0x00,
    49.             SET_COM_PIN_CFG, 0x02 if self.height == 32 else 0x12,
    50.             # timing and driving scheme
    51.             SET_DISP_CLK_DIV, 0x80,
    52.             SET_PRECHARGE, 0x22 if self.external_vcc else 0xf1,
    53.             SET_VCOM_DESEL, 0x30, # 0.83*Vcc
    54.             # display
    55.             SET_CONTRAST, 0xff, # maximum
    56.             SET_ENTIRE_ON, # output follows RAM contents
    57.             SET_NORM_INV, # not inverted
    58.             # charge pump
    59.             SET_CHARGE_PUMP, 0x10 if self.external_vcc else 0x14,
    60.             SET_DISP | 0x01): # on
    61.             self.write_cmd(cmd)
    62.         self.fill(0)
    63.         self.show()
    64.  
    65.     def poweroff(self):
    66.         self.write_cmd(SET_DISP | 0x00)
    67.  
    68.     def contrast(self, contrast):
    69.         self.write_cmd(SET_CONTRAST)
    70.         self.write_cmd(contrast)
    71.  
    72.     def invert(self, invert):
    73.         self.write_cmd(SET_NORM_INV | (invert & 1))
    74.  
    75.     def show(self):
    76.         x0 = 0
    77.         x1 = self.width - 1
    78.         if self.width == 64:
    79.             # displays with width of 64 pixels are shifted by 32
    80.             x0 += 32
    81.             x1 += 32
    82.         self.write_cmd(SET_COL_ADDR)
    83.         self.write_cmd(x0)
    84.         self.write_cmd(x1)
    85.         self.write_cmd(SET_PAGE_ADDR)
    86.         self.write_cmd(0)
    87.         self.write_cmd(self.pages - 1)
    88.         self.write_framebuf()
    89.  
    90.     def fill(self, col):
    91.         self.framebuf.fill(col)
    92.  
    93.     def pixel(self, x, y, col):
    94.         self.framebuf.pixel(x, y, col)
    95.  
    96.     def scroll(self, dx, dy):
    97.         self.framebuf.scroll(dx, dy)
    98.  
    99.     def text(self, string, x, y, col=1):
    100.         self.framebuf.text(string, x, y, col)
    101.  
    102.  
    103. class SSD1306_I2C(SSD1306):
    104.     def __init__(self, width, height, i2c, addr=0x3c, external_vcc=False):
    105.         self.i2c = i2c
    106.         self.addr = addr
    107.         self.temp = bytearray(2)
    108.         # Add an extra byte to the data buffer to hold an I2C data/command byte
    109.         # to use hardware-compatible I2C transactions.  A memoryview of the
    110.         # buffer is used to mask this byte from the framebuffer operations
    111.         # (without a major memory hit as memoryview doesn't copy to a separate
    112.         # buffer).
    113.         self.buffer = bytearray(((height // 8) * width) + 1)
    114.         self.buffer[0] = 0x40  # Set first byte of data buffer to Co=0, D/C=1
    115.         self.framebuf = framebuf.FrameBuffer1(memoryview(self.buffer)[1:], width, height)
    116.         super().__init__(width, height, external_vcc)
    117.  
    118.     def write_cmd(self, cmd):
    119.         self.temp[0] = 0x80 # Co=1, D/C#=0
    120.         self.temp[1] = cmd
    121.         self.i2c.writeto(self.addr, self.temp)
    122.  
    123.     def write_framebuf(self):
    124.         # Blast out the frame buffer using a single I2C transaction to support
    125.         # hardware I2C interfaces.
    126.         self.i2c.writeto(self.addr, self.buffer)
    127.  
    128.     def poweron(self):
    129.         pass
    130.  
    131.  
    132. class SSD1306_SPI(SSD1306):
    133.     def __init__(self, width, height, spi, dc, res, cs, external_vcc=False):
    134.         self.rate = 10 * 1024 * 1024
    135.         dc.init(dc.OUT, value=0)
    136.         res.init(res.OUT, value=0)
    137.         cs.init(cs.OUT, value=1)
    138.         self.spi = spi
    139.         self.dc = dc
    140.         self.res = res
    141.         self.cs = cs
    142.         self.buffer = bytearray((height // 8) * width)
    143.         self.framebuf = framebuf.FrameBuffer1(self.buffer, width, height)
    144.         super().__init__(width, height, external_vcc)
    145.  
    146.     def write_cmd(self, cmd):
    147.         self.spi.init(baudrate=self.rate, polarity=0, phase=0)
    148.         self.cs.high()
    149.         self.dc.low()
    150.         self.cs.low()
    151.         self.spi.write(bytearray([cmd]))
    152.         self.cs.high()
    153.  
    154.     def write_framebuf(self):
    155.         self.spi.init(baudrate=self.rate, polarity=0, phase=0)
    156.         self.cs.high()
    157.         self.dc.high()
    158.         self.cs.low()
    159.         self.spi.write(self.buffer)
    160.         self.cs.high()
    161.  
    162.     def poweron(self):
    163.         self.res.high()
    164.         time.sleep_ms(1)
    165.         self.res.low()
    166.         time.sleep_ms(10)
    167.         self.res.high()

    示例代码1

    1. from machine import Pin, SoftI2C  # 导入Pin和软I2C模块
    2. from time import sleep  # 导入时间模块
    3. import ssd1306  # 导入屏幕驱动模块
    4.  
    5.  
    6. # 创建i2c对象
    7. i2c = SoftI2C(scl=Pin(22), sda=Pin(21))  # 时钟接Pin22，数据接Pin21
    8.  
    9. # 宽度高度，屏幕宽高为128*64 像素
    10. oled_width = 128  
    11. oled_height = 64
    12.  
    13. # 创建oled屏幕对象
    14. oled = ssd1306.SSD1306_I2C(oled_width, oled_height, i2c)  # 设置宽度，高度和I2C通信
    15.  
    16. # 在指定位置处显示文字
    17. oled.text('Shanghai!', 0, 0)  # 在屏幕的左上角开始显示
    18. oled.text('Beijing welcome!', 0, 15) 
    19. oled.text('Guangzhou beautiful!', 0, 25)
    20.         
    21. oled.show()  # 显示文字

    示例代码2

    1. from machine import Pin, I2C  # 导入PIN和I2C
    2. from ssd1306 import SSD1306_I2C  # 导入屏幕驱动
    3.  
    4. #OLED=....
    5. i2c = I2C(scl=Pin(22), sda=Pin(21))  # 创建I2C对象
    6. OLED= SSD1306_I2C(128, 64, i2c)  # 创建OLED对象
    7.  
    8. #fonts=....字使用字典，字典的key来放字的编码的十六进制，键来放字模
    9. fonts= {
    10.     0xE5A5BD:
    11.     [0x00,0x04,0x08,0x10,0x20,0xFF,0x11,0x12,0x14,0x18,0x24,0x42,0x00,0x00,0x00,0x00,
    12.     0x00,0x00,0xF8,0x10,0x20,0xF8,0x40,0x20,0x10,0x08,0x28,0x10,0x00,0x00,0x00,0x00],  # 好
    13.     
    14.     0xE4BABA:
    15.     [0x00,0x01,0x01,0x01,0x01,0x02,0x04,0x08,0x10,0x20,0x00,0x00,0x00,0x00,0x00,0x00,
    16.     0x00,0x00,0x00,0x00,0x00,0x80,0x40,0x20,0x10,0x08,0x00,0x00,0x00,0x00,0x00,0x00],  # 人
    17.     
    18.     0xE5A49A:
    19.     [0x00,0x02,0x04,0x0F,0x18,0x25,0x02,0x0D,0x12,0x04,0x00,0x01,0x00,0x00,0x00,0x00,
    20.     0x00,0x00,0x00,0x80,0xA0,0x40,0xF8,0x08,0xD0,0x20,0x40,0x80,0x00,0x00,0x00,0x00],  # 多
    21. }
    22.  
    23.  
    24. # 顶替中文函数部分
    25. def chinese(ch_str, x_axis, y_axis):  # 需要显示的中文，x轴的开始位置，y轴的开始位置
    26.    offset_ = 0  # 偏移量设为0，也可以设为其他值，俺需要修正
    27.    for k in ch_str:   # for循环去除每个字
    28.        code = 0x00  # 将中文转成16进制编码 
    29.        data_code = k.encode("utf-8")  # 编码为utf-8格式
    30.        code |= data_code[0] << 16
    31.        code |= data_code[1] << 8
    32.        code |= data_code[2]
    33.        byte_data = fonts[code]
    34.        for y in range(0, 16):
    35.            a_ = bin(byte_data[y]).replace('0b', '')
    36.            while len(a_) < 8:
    37.                a_ = '0'+ a_
    38.            b_ = bin(byte_data[y+16]).replace('0b', '')
    39.            while len(b_) < 8:
    40.                b_ = '0'+ b_
    41.            for x in range(0, 8):
    42.                OLED.pixel(x_axis + offset_ + x,     y+y_axis, int(a_[x]))   
    43.                OLED.pixel(x_axis + offset_ + x + 8, y+y_axis, int(b_[x]))   
    44.        offset_ += 16
    45.  
    46. chinese('好人多', 35, 4)  # 需要显示的中文
    47. OLED.show()  # 显示
    48. OLED.text('welcome to china', 0, 32)  # 需要显示的英文
    49. OLED.show()  # 显示

    四、演示效果

    示例代码1的效果：

    示例代码2的效果：

     也可以点开如下地址，在线查看效果：

    Wokwi Arduino and ESP32 Simulatoricon-default.png?t=M85Bhttps://wokwi.com/projects/348669376140935763

    五、设计字库

            我们显示中文，需要对中文进行设计，然后再让屏幕显示出来。请看如下操作：

    1，我们通过如下网址，可以得到中文和UTF-8之间的相互转换。

    查看字符编码（UTF-8）

     2，通过如下工具，制作汉子对应的形状。

             工具大家可以在文末的链接内下载找到。如果你是英文版本系统，或者你打开这个工具后显示乱码。需要对你的系统进行设置。下面以Win10为例讲解如何设置。

            1，打开控制面板，找到 时钟和地区，按如下操作即可

     

     

     2，我们打开工具PCtoLCD2002，按如下步骤进行操作

     

     

     

     

     

     然后我们复制上图红框中的数据，粘贴到代码中对应的汉字的即可。

     

    六、购买

    某宝链接如下：
    https://item.taobao.com/item.htm?spm=a230r.1.14.32.788158fdpYtkII&id=573950296900&ns=1&abbucket=8#detail

     

    产品规格：0.96寸OLED裸屏-30P-1306技术资料

    对应技术资料下载地址：https://pan.baidu.com/s/1_P7dey5xLMGfZ70UylNm7w

    提取码：xnn1

    产品规格：0.96寸OLED带板带字库-1306技术资料

    对应技术资料下载地址：https://pan.baidu.com/s/12aTj4TzXrw3ynlDJcmKewA

    提取码：1bqm

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  • 原文地址：https://blog.csdn.net/zhusongziye/article/details/127892333