环境需求
Python版本大于等于3.8、Thonny软件、EPS32已烧录MicroPython固件，可参考上一篇文章 ESP32初学教程Python版-从环境搭建到完成控制LED灯闪烁
硬件需求
EPS32开发板、DHT11的温湿度传感器、OLEAD显示屏、杜邦线、安卓数据线
引脚连接
DHT11温湿度传感器连接ESP32
使用杜邦线连接传感器与EPS32，将DHT11的温湿度传感器VCC、DATA、GND引脚分别连接到EPS32的3V3、GND、D4引脚，如下图。
OLEAD显示屏连接ESP32
使用杜邦线连接OLEAD显示屏与EPS32，将OLEAD显示屏的VCC、GND、SCL、SDA引脚分别连接到EPS32的VIN、GND、D22、D21引脚，如下图。
编写温湿度读取代码
用数据线将ESP32和电脑连接，打开Thonny软件，新建文件ssd1306.py，加入如下代码
#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()这个ssd1306完整库可以在官方下载，但是这里我主要是将读取的数据显示到显示屏上，因此只需要这一个文件即可。
新建文件名为main.py，加入如下代码
from machine import Pin, I2C
import dht
import time
import ssd1306
# 设置I2C引脚
i2c = I2C(0, scl=Pin(22), sda=Pin(21), freq=200000)
# 初始化显示屏
oled = ssd1306.SSD1306_I2C(128, 64, i2c)
# 设置DHT11传感器
dht_sensor = dht.DHT11(Pin(4)) # 将4替换为实际连接的引脚编号
while True:
try:
# 读取传感器数据
dht_sensor.measure()
temperature = dht_sensor.temperature() # 获取温度
humidity = dht_sensor.humidity() # 获取湿度
# 打印温湿度数据
print("温度: {}°C".format(temperature))
print("湿度: {}%".format(humidity))
# 清空屏幕并显示数据
oled.fill(0) # 清空屏幕
oled.text('Temperature: {}C'.format(temperature), 0, 0)
oled.text('Humidity: {}%'.format(humidity), 0, 20)
oled.show() # 刷新屏幕
except OSError as e:
print("Failed to read sensor data:", e)
time.sleep(2) # 每2秒读取一次数据需要注意的是在显示屏上无法显示中文，打印是可以的。
启动程序
直接启动在Thonny运行程序，看Thonny控制台是否有温度湿度数据打印，并查看显示屏是否有显示，如图可以看到成功了
结语
以上是幽络源的EPS32+DHT11温湿传感器+OLEAD显示屏整合MicroPython实现温湿度读取并显示的教程，适合初学者理解与学习。如有不懂之处可在评论区留言或加Q群询问307531422
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