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电子产品世界 » 论坛首页 » 嵌入式开发 » STM32 » MicroPython-ESP8266开发板控制OLED液晶显示屏教程实例附代码

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MicroPython-ESP8266开发板控制OLED液晶显示屏教程实例附代码

bodasister
助工
2017-06-05 16:01:32     打赏
1.实验目的

1.学习在PC机系统中扩展简单I/O接口的方法。

2.进一步学习编制数据输出程序的设计方法。

3.学习TPYBoardv202控制OLED显示字符。

2.所需元器件

TPYBoardv202开发板一块

数据线一条

杜邦线若干

OLED液晶屏一块

3.什么是OLED显示屏

(1)OLED显示屏简介

有机发光二极管（organiclight-emittingdiode，OLED）是一种由柯达公司开发并拥有专利的显示技术，这项技术使用有机聚合材料作为发光二极管中的半导体（semiconductor）材料。聚合材料可以是天然的，也可能是人工合成的，可能尺寸很大，也可能尺寸很小。其广泛运用于手机、数码摄像机、DVD机、个人数字助理（PDA）、笔记本电脑、汽车音响和电视。OLED显示器很薄很轻，因为它不使用背光。

本例中使用0.96寸OLED显示屏，该屏具有高亮度，低功耗屏，显示颜色纯正，在阳光下有很好的可视效果。模块供电可以是3.3V也可以是5V，不需要修改模块电路，同时兼容3种通信方式：4线SPI、3线SPI、IIC，通信模式的选择可以根据提供的BOM表进行跳选。该模块一共有三种颜色：蓝色、白色、黄蓝双色。OLED屏具有多个控制指令，可以控制OLED的亮度、对比度、开关升压电路等指令。操作方便，功能丰富。同时为了方便应用在产品上，预留4个M2固定孔，方便用户固定在机壳上。0.96寸OLED显示屏的驱动芯片为：SSD1306(已集成在屏中)。

(2)实际显示效果



(3)OLED接口定义

1>GND=电源地

2>VCC=电源地（2.8V~5.5V）

3>D0=时钟线

4>D1=数据线

5>RES=复位线

6>DC=数据/命令

7>CS=片选

4.具体接线方法


TPYboard v202

OLED

GND

GND

3.3V

VCC

SCK

D0

MO

D1

G4

RES

G5

DC

G16

CS













5.实物接线图



6.程序源代码

 

main.py 程序源代码 



# main.py -- put your code here!
import machine
from machine import Pin,I2C,SPI
import ssd1306
import math
import time

spi = SPI(baudrate=10000000, polarity=1, phase=0, sck=Pin(14,Pin.OUT), mosi=Pin(13,Pin.OUT), miso=Pin(12))
display = ssd1306.SSD1306_SPI(128, 64, spi, Pin(5),Pin(4), Pin(16))

led_blue = machine.Pin(2, Pin.OUT)  # 设置 GPIO2 为输出
led_blue.high()

try:
  display.poweron()
  display.init_display()

  display.text('TPYBoard V202',1,1)
  display.text('Hi, TurnipSmart',1,16)
  display.text('I Love You',1,31)
  display.text('This is DNA!!',1,46)
  display.show()
  time.sleep(3)
  display.fill(0)
  #显示DNA
  for x in range(0, 128):
    display.pixel(x, 32+int(math.cos(x/64*math.pi)*30 +2), 1)
    display.pixel(x, 32+int(math.cos((x+64)/64*math.pi)*30+2), 1)
  display.show()
except Exception as ex:
  led_blue.low()
  print('Unexpected error: {0}'.format(ex))
  display.poweroff()

 


ssd1306程序源代码 

import pyb
import font

# Constants
DISPLAYOFF          = 0xAE
SETCONTRAST         = 0x81
DISPLAYALLON_RESUME = 0xA4
DISPLAYALLON        = 0xA5
NORMALDISPLAY       = 0xA6
INVERTDISPLAY       = 0xA7
DISPLAYON           = 0xAF
SETDISPLAYOFFSET    = 0xD3
SETCOMPINS          = 0xDA
SETVCOMDETECT       = 0xDB
SETDISPLAYCLOCKDIV  = 0xD5
SETPRECHARGE        = 0xD9
SETMULTIPLEX        = 0xA8
SETLOWCOLUMN        = 0x00
SETHIGHCOLUMN       = 0x10
SETSTARTLINE        = 0x40
MEMORYMODE          = 0x20
COLUMNADDR          = 0x21
PAGEADDR            = 0x22
COMSCANINC          = 0xC0
COMSCANDEC          = 0xC8
SEGREMAP            = 0xA0
CHARGEPUMP          = 0x8D
EXTERNALVCC         = 0x10
SWITCHCAPVCC        = 0x20
SETPAGEADDR         = 0xB0
SETCOLADDR_LOW      = 0x00
SETCOLADDR_HIGH     = 0x10
ACTIVATE_SCROLL                      = 0x2F
DEACTIVATE_SCROLL                    = 0x2E
SET_VERTICAL_SCROLL_AREA             = 0xA3
RIGHT_HORIZONTAL_SCROLL              = 0x26
LEFT_HORIZONTAL_SCROLL               = 0x27
VERTICAL_AND_RIGHT_HORIZONTAL_SCROLL = 0x29
VERTICAL_AND_LEFT_HORIZONTAL_SCROLL  = 0x2A

# I2C devices are accessed through a Device ID. This is a 7-bit
# value but is sometimes expressed left-shifted by 1 as an 8-bit value.
# A pin on SSD1306 allows it to respond to ID 0x3C or 0x3D. The board
# I bought from ebay used a 0-ohm resistor to select between "0x78"
# (0x3c << 1) or "0x7a" (0x3d << 1). The default was set to "0x78"
DEVID = 0x3c

# I2C communication here is either <DEVID> <CTL_CMD> <command byte>
# or <DEVID> <CTL_DAT> <display buffer bytes> <> <> <> <>...
# These two values encode the Co (Continuation) bit as b7 and the
# D/C# (Data/Command Selection) bit as b6.
CTL_CMD = 0x80
CTL_DAT = 0x40

class SSD1306(object):

  def __init__(self, pinout, height=32, external_vcc=True, i2c_devid=DEVID):
    self.external_vcc = external_vcc
    self.height       = 32 if height == 32 else 64
    self.pages        = int(self.height / 8)
    self.columns      = 128

    # Infer interface type from entries in pinout{}
    if 'dc' in pinout:
      # SPI
      rate = 16 * 1024 * 1024
      self.spi = pyb.SPI(1, pyb.SPI.MASTER, baudrate=rate, polarity=1, phase=0)  # SCK: Y6: MOSI: Y8
      self.dc  = pyb.Pin(pinout['dc'],  pyb.Pin.OUT_PP, pyb.Pin.PULL_DOWN)
      self.res = pyb.Pin(pinout['res'], pyb.Pin.OUT_PP, pyb.Pin.PULL_DOWN)
      self.offset = 0
    else:
      # Infer bus number from pin
      if pinout['sda'] == 'X10':
        self.i2c = pyb.I2C(1)
      else:
        self.i2c = pyb.I2C(2)
      self.i2c.init(pyb.I2C.MASTER, baudrate=400000) # 400kHz
      self.devid = i2c_devid
      # used to reserve an extra byte in the image buffer AND as a way to
      # infer the interface type
      self.offset = 1
      # I2C command buffer
      self.cbuffer = bytearray(2)
      self.cbuffer[0] = CTL_CMD

  def clear(self):
    self.buffer = bytearray(self.offset + self.pages * self.columns)
    if self.offset == 1:
      self.buffer[0] = CTL_DAT

  def write_command(self, command_byte):
    if self.offset == 1:
      self.cbuffer[1] = command_byte
      self.i2c.send(self.cbuffer, addr=self.devid, timeout=5000)
    else:
      self.dc.low()
      self.spi.send(command_byte)

  def invert_display(self, invert):
    self.write_command(INVERTDISPLAY if invert else NORMALDISPLAY)

  def display(self):
    self.write_command(COLUMNADDR)
    self.write_command(0)
    self.write_command(self.columns - 1)
    self.write_command(PAGEADDR)
    self.write_command(0)
    self.write_command(self.pages - 1)
    if self.offset == 1:
      self.i2c.send(self.buffer, addr=self.devid, timeout=5000)
    else:
      self.dc.high()
      self.spi.send(self.buffer)

  def set_pixel(self, x, y, state):
    index = x + (int(y / 8) * self.columns)
    if state:
      self.buffer[self.offset + index] |= (1 << (y & 7))
    else:
      self.buffer[self.offset + index] &= ~(1 << (y & 7))

  def init_display(self):
    chargepump = 0x10 if self.external_vcc else 0x14
    precharge  = 0x22 if self.external_vcc else 0xf1
    multiplex  = 0x1f if self.height == 32 else 0x3f
    compins    = 0x02 if self.height == 32 else 0x12
    contrast   = 0xff # 0x8f if self.height == 32 else (0x9f if self.external_vcc else 0x9f)
    data = [DISPLAYOFF,
            SETDISPLAYCLOCKDIV, 0x80,
            SETMULTIPLEX, multiplex,
            SETDISPLAYOFFSET, 0x00,
            SETSTARTLINE | 0x00,
            CHARGEPUMP, chargepump,
            MEMORYMODE, 0x00,
            SEGREMAP | 0x10,
            COMSCANDEC,
            SETCOMPINS, compins,
            SETCONTRAST, contrast,
            SETPRECHARGE, precharge,
            SETVCOMDETECT, 0x40,
            DISPLAYALLON_RESUME,
            NORMALDISPLAY,
            DISPLAYON]
    for item in data:
      self.write_command(item)
    self.clear()
    self.display()

  def poweron(self):
    if self.offset == 1:
      pyb.delay(10)
    else:
      self.res.high()
      pyb.delay(1)
      self.res.low()
      pyb.delay(10)
      self.res.high()
      pyb.delay(10)

  def poweroff(self):
    self.write_command(DISPLAYOFF)

  def contrast(self, contrast):
    self.write_command(SETCONTRAST)
    self.write_command(contrast)

  def draw_text(self, x, y, string, size=1, space=1):
    def pixel_x(char_number, char_column, point_row):
      char_offset = x + char_number * size * font.cols + space * char_number
      pixel_offset = char_offset + char_column * size + point_row
      return self.columns - pixel_offset

    def pixel_y(char_row, point_column):
      char_offset = y + char_row * size
      return char_offset + point_column

    def pixel_mask(char, char_column, char_row):
      char_index_offset = ord(char) * font.cols
      return font.bytes[char_index_offset + char_column] >> char_row & 0x1

    pixels = (
      (pixel_x(char_number, char_column, point_row),
       pixel_y(char_row, point_column),
       pixel_mask(char, char_column, char_row))
      for char_number, char in enumerate(string)
      for char_column in range(font.cols)
      for char_row in range(font.rows)
      for point_column in range(size)
      for point_row in range(1, size + 1))

    for pixel in pixels:
      self.set_pixel(*pixel)

 





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熊猫爱善
管理员
2017-06-05 18:40:27     打赏
2楼
谢谢楼主分享

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eepwnet
专家
2017-06-06 12:18:00     打赏
3楼
谢谢楼主分享

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