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，之前我们使用的是I2C协议，这里我们使用SPI协议来控制。大家可自行百度学习一下SPI。

物联网开发笔记（48）- 使用Micropython开发ESP32开发板之控制OLED ssd1306屏幕_micropython ssd1306_魔都飘雪的博客-CSDN博客使用Micropython开发ESP32开发板之控制OLED ssd1306屏幕https://blog.csdn.net/zhusongziye/article/details/127892333?spm=1001.2014.3001.5501物联网开发笔记（70）- 使用Micropython开发ESP32开发板之控制OLED ssd1306屏幕（续）_魔都飘雪的博客-CSDN博客使用Micropython开发ESP32开发板之控制OLED ssd1306屏幕（续）显示中文https://blog.csdn.net/zhusongziye/article/details/128619804?spm=1001.2014.3001.5501

MicroPython 官方SPI使用方法介绍：

Quick reference for the ESP32 — MicroPython latest documentationhttp://docs.micropython.org/en/latest/esp32/quickref.html#software-spi-bus

二、环境

        ESP32 + OLED ssd1306屏幕 + Thonny IDE（或者WOKWI在线仿真） + 几根杜邦线 + Win10

 接线方法：

 

三、屏幕驱动

SSD1306.py中带有的函数不多，主要函数有：

• text(string, x, y)，在(x, y)处显示字符串，注意text()函数内置的字体是8x8的，暂时不能替换
• poweroff()，关闭OLED显示
• poweron()，空函数，无任何效果。可以用 write_cmd(0xAF) 代替
• fill(n)，n=0，清空屏幕，n大于0，填充屏幕
• contrast()，调整亮度。0最暗，255最亮
• invert()，奇数时反相显示，偶数时正常显示
• pixel(x, y, c)，在(x, y)处画点
• show()，更新显示内容。前面大部分函数只是写入数据到缓冲区，并不会直接显示到屏幕，需要调用show()后才能显示出来。

屏幕驱动ssd1306.py（和之前我们学习I2C的是一样的）：

# ssd1306.py
#MicroPython SSD1306 OLED driver, I2C and SPI interfaces created by Adafruit
 
import time
import framebuf
 
# register definitions
SET_CONTRAST        = const(0x81)
SET_ENTIRE_ON       = const(0xa4)
SET_NORM_INV        = const(0xa6)
SET_DISP            = const(0xae)
SET_MEM_ADDR        = const(0x20)
SET_COL_ADDR        = const(0x21)
SET_PAGE_ADDR       = const(0x22)
SET_DISP_START_LINE = const(0x40)
SET_SEG_REMAP       = const(0xa0)
SET_MUX_RATIO       = const(0xa8)
SET_COM_OUT_DIR     = const(0xc0)
SET_DISP_OFFSET     = const(0xd3)
SET_COM_PIN_CFG     = const(0xda)
SET_DISP_CLK_DIV    = const(0xd5)
SET_PRECHARGE       = const(0xd9)
SET_VCOM_DESEL      = const(0xdb)
SET_CHARGE_PUMP     = const(0x8d)
 
 
class SSD1306:
    def __init__(self, width, height, external_vcc):
        self.width = width
        self.height = height
        self.external_vcc = external_vcc
        self.pages = self.height // 8
        # Note the subclass must initialize self.framebuf to a framebuffer.
        # This is necessary because the underlying data buffer is different
        # between I2C and SPI implementations (I2C needs an extra byte).
        self.poweron()
        self.init_display()
 
    def init_display(self):
        for cmd in (
            SET_DISP | 0x00, # off
            # address setting
            SET_MEM_ADDR, 0x00, # horizontal
            # resolution and layout
            SET_DISP_START_LINE | 0x00,
            SET_SEG_REMAP | 0x01, # column addr 127 mapped to SEG0
            SET_MUX_RATIO, self.height - 1,
            SET_COM_OUT_DIR | 0x08, # scan from COM[N] to COM0
            SET_DISP_OFFSET, 0x00,
            SET_COM_PIN_CFG, 0x02 if self.height == 32 else 0x12,
            # timing and driving scheme
            SET_DISP_CLK_DIV, 0x80,
            SET_PRECHARGE, 0x22 if self.external_vcc else 0xf1,
            SET_VCOM_DESEL, 0x30, # 0.83*Vcc
            # display
            SET_CONTRAST, 0xff, # maximum
            SET_ENTIRE_ON, # output follows RAM contents
            SET_NORM_INV, # not inverted
            # charge pump
            SET_CHARGE_PUMP, 0x10 if self.external_vcc else 0x14,
            SET_DISP | 0x01): # on
            self.write_cmd(cmd)
        self.fill(0)
        self.show()
 
    def poweroff(self):
        self.write_cmd(SET_DISP | 0x00)
 
    def contrast(self, contrast):
        self.write_cmd(SET_CONTRAST)
        self.write_cmd(contrast)
 
    def invert(self, invert):
        self.write_cmd(SET_NORM_INV | (invert & 1))
 
    def show(self):
        x0 = 0
        x1 = self.width - 1
        if self.width == 64:
            # displays with width of 64 pixels are shifted by 32
            x0 += 32
            x1 += 32
        self.write_cmd(SET_COL_ADDR)
        self.write_cmd(x0)
        self.write_cmd(x1)
        self.write_cmd(SET_PAGE_ADDR)
        self.write_cmd(0)
        self.write_cmd(self.pages - 1)
        self.write_framebuf()
 
    def fill(self, col):
        self.framebuf.fill(col)
 
    def pixel(self, x, y, col):
        self.framebuf.pixel(x, y, col)
 
    def scroll(self, dx, dy):
        self.framebuf.scroll(dx, dy)
 
    def text(self, string, x, y, col=1):
        self.framebuf.text(string, x, y, col)
 
 
class SSD1306_I2C(SSD1306):
    def __init__(self, width, height, i2c, addr=0x3c, external_vcc=False):
        self.i2c = i2c
        self.addr = addr
        self.temp = bytearray(2)
        # Add an extra byte to the data buffer to hold an I2C data/command byte
        # to use hardware-compatible I2C transactions.  A memoryview of the
        # buffer is used to mask this byte from the framebuffer operations
        # (without a major memory hit as memoryview doesn't copy to a separate
        # buffer).
        self.buffer = bytearray(((height // 8) * width) + 1)
        self.buffer[0] = 0x40  # Set first byte of data buffer to Co=0, D/C=1
        self.framebuf = framebuf.FrameBuffer1(memoryview(self.buffer)[1:], width, height)
        super().__init__(width, height, external_vcc)
 
    def write_cmd(self, cmd):
        self.temp[0] = 0x80 # Co=1, D/C#=0
        self.temp[1] = cmd
        self.i2c.writeto(self.addr, self.temp)
 
    def write_framebuf(self):
        # Blast out the frame buffer using a single I2C transaction to support
        # hardware I2C interfaces.
        self.i2c.writeto(self.addr, self.buffer)
 
    def poweron(self):
        pass
 
 
class SSD1306_SPI(SSD1306):
    def __init__(self, width, height, spi, dc, res, cs, external_vcc=False):
        self.rate = 10 * 1024 * 1024
        dc.init(dc.OUT, value=0)
        res.init(res.OUT, value=0)
        cs.init(cs.OUT, value=1)
        self.spi = spi
        self.dc = dc
        self.res = res
        self.cs = cs
        self.buffer = bytearray((height // 8) * width)
        self.framebuf = framebuf.FrameBuffer1(self.buffer, width, height)
        super().__init__(width, height, external_vcc)
 
    def write_cmd(self, cmd):
        self.spi.init(baudrate=self.rate, polarity=0, phase=0)
        self.cs.high()
        self.dc.low()
        self.cs.low()
        self.spi.write(bytearray([cmd]))
        self.cs.high()
 
    def write_framebuf(self):
        self.spi.init(baudrate=self.rate, polarity=0, phase=0)
        self.cs.high()
        self.dc.high()
        self.cs.low()
        self.spi.write(self.buffer)
        self.cs.high()
 
    def poweron(self):
        self.res.high()
        time.sleep_ms(1)
        self.res.low()
        time.sleep_ms(10)
        self.res.high()

四、示例代码1

此处使用软SPI模式

from machine import Pin,SoftSPI
from ssd1306 import SSD1306_SPI

dc=Pin(2,Pin.OUT)
res=Pin(15,Pin.OUT)
cs=Pin(4,Pin.OUT)

#波特率；输出极性；相位，此处没用到，0和1都可；sck时钟同步信号线D0；mosi主机发送引脚D1；mosi主机接收引脚,此处用不到
spi=SoftSPI(baudrate=100000,polarity=1,phase=0,sck=Pin(18),mosi=Pin(23),miso=Pin(19))
oled=SSD1306_SPI(128,64,spi,dc,res,cs)  #创建oled对象

def main():
    oled.fill(0) # 清屏
    oled.text("hello",24,28,1) # 要显示的字符；x坐标；y坐标；显示1，不显示0
    oled.show() # 显示

if __name__=="__main__":
    main()

五、示例代码2

此处使用硬SPI模式

from machine import Pin,SPI
from ssd1306 import SSD1306_SPI

dc=Pin(2,Pin.OUT)
res=Pin(15,Pin.OUT)
cs=Pin(4,Pin.OUT)

#波特率；输出极性；相位，此处没用到，0和1都可；sck时钟同步信号线D0；mosi主机发送引脚D1；mosi主机接收引脚,此处用不到
# SPI 1不能大于10M，SPI 2不能大于80M，
spi=SPI(2,baudrate=80000000,polarity=1,phase=0,sck=Pin(18),mosi=Pin(23),miso=Pin(19))
oled=SSD1306_SPI(128,64,spi,dc,res,cs)  #创建oled对象

def main():
    oled.fill(0) # 清屏
    oled.text("hello",24,28,1) # 要显示的字符；x坐标；y坐标；显示1，不显示0
    oled.show() # 显示

if __name__=="__main__":
    main()

六、示例代码3

此处使用硬SPI模式。给出了几种创建spi对象的方法。

from machine import Pin,SPI
from ssd1306 import SSD1306_SPI

dc=Pin(2,Pin.OUT)
res=Pin(15,Pin.OUT)
cs=Pin(4,Pin.OUT)

#波特率；输出极性；相位，此处没用到，0和1都可；sck时钟同步信号线D0；mosi主机发送引脚D1；mosi主机接收引脚,此处用不到
# SPI 1不能大于10M，SPI 2不能大于80M，
#spi=SPI(2,baudrate=80000000,polarity=1,phase=0,bits=8,firstbit=0,sck=Pin(18),mosi=Pin(23),miso=Pin(19))

#spi=SPI(1,baudrate=10000000,polarity=1,phase=0,sck=Pin(18),mosi=Pin(23),miso=Pin(19))
#spi=SPI(2,baudrate=80000000,polarity=1,phase=0,sck=Pin(18),mosi=Pin(23),miso=Pin(19))

# 简易模式
#spi=SPI(1,10000000,sck=Pin(18),mosi=Pin(23),miso=Pin(19))
spi=SPI(2,80000000,sck=Pin(18),mosi=Pin(23),miso=Pin(19))
oled=SSD1306_SPI(128,64,spi,dc,res,cs)  #创建oled对象

def main():
    oled.fill(0) # 清屏
    oled.text("hello",24,28,1) # 要显示的字符；x坐标；y坐标；显示1，不显示0
    oled.show() # 显示

if __name__=="__main__":
    main()

七、示例代码4

我们结合温度传感器，可以把温蒂显示在屏幕上。温度传感器的使用方法请看下面文章：

物联网开发笔记（38）- 使用Micropython开发ESP32开发板之控制温度传感器（DS18B20）_魔都飘雪的博客-CSDN博客_esp32 温度传感器使用Micropython开发ESP32开发板之控制温度传感器（DS18B20）https://blog.csdn.net/zhusongziye/article/details/127794068?spm=1001.2014.3001.5501

from machine import Pin,SPI
from ssd1306 import SSD1306_SPI
import onewire, ds18x20,time

dc=Pin(2,Pin.OUT)
res=Pin(15,Pin.OUT)
cs=Pin(4,Pin.OUT)

#波特率；输出极性；相位，此处没用到，0和1都可；sck时钟同步信号线D0；mosi主机发送引脚D1；mosi主机接收引脚,此处用不到
# SPI 1不能大于10M，SPI 2不能大于80M，
#spi=SPI(2,baudrate=80000000,polarity=1,phase=0,bits=8,firstbit=0,sck=Pin(18),mosi=Pin(23),miso=Pin(19))

#spi=SPI(1,baudrate=10000000,polarity=1,phase=0,sck=Pin(18),mosi=Pin(23),miso=Pin(19))
#spi=SPI(2,baudrate=80000000,polarity=1,phase=0,sck=Pin(18),mosi=Pin(23),miso=Pin(19))

# 简易模式
#spi=SPI(1,10000000,sck=Pin(18),mosi=Pin(23),miso=Pin(19))
spi=SPI(2,80000000,sck=Pin(18),mosi=Pin(23),miso=Pin(19))
oled=SSD1306_SPI(128,64,spi,dc,res,cs)  #创建oled对象

ds_sensor=ds18x20.DS18X20(onewire.OneWire(Pin(22)))

def ds18x20_read_temp():
    roms=ds_sensor.scan()
    ds_sensor.convert_temp()
    time.sleep_ms(750)
    for rom in roms:
        temp=ds_sensor.read_temp(rom)
    return temp

def main():
    oled.fill(0) # 清屏
    oled.text("temp = %.2f" % ds18x20_read_temp(),24,28,1) # 要显示的字符；x坐标；y坐标；显示1，不显示0
    oled.show() # 显示
    print("temp = %.2f" % ds18x20_read_temp())

if __name__=="__main__":
    main()

八、屏幕某宝购买地址

https://item.taobao.com/item.htm?spm=a1z09.2.0.0.51c12e8dAFTJdZ&id=562145367495&_u=4p01rch5d1dhttps://item.taobao.com/item.htm?spm=a1z09.2.0.0.51c12e8dAFTJdZ&id=562145367495&_u=4p01rch5d1d

0.96寸（7管脚）资料下载链接：

https://pan.baidu.com/s/1Q0OzdXnCVVVgomYQSeIhAg                       提取码：7lcx

 

九、遗留问题：

会出现如下问题，知道的可以评论区留言：