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

2017-6-5 14:36:15 18698 液晶显示屏

`　　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

TPYboard v202	OLED
GND	GND
3.3V	VCC
SCK	D0
MO	D1
G4	RES
G5	DC
G16	CS

　4.实物接线图

　5.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()

复制代码

　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
# or <> <> <> <>...
# 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)