代码收藏家 物联网开发笔记（28）- 使用Micropython开发ESP32开发板之控制240×240的oled屏幕显示图片（ST7789芯片）
这一节我们接着上一节继续讲解如何控制240×240的oled屏幕。
一、目的
使用MicroPython开发ESP32开发板控制240×240的oled屏幕，显示图片。
二、环境
ESP32 + 240×240的oled彩色屏幕+ Thonny IDE + 几根杜邦线
接线方式请看上一节，此处不再重复赘述。
三、屏幕驱动
上一节我们使用了两个驱动，完成了文字的显示，但是这两个驱动各有不足之处：
所以这里对齐进行了升级，大家使用下面的新驱动st7789_new.py，来显示图片哈：
链接: https://pan.baidu.com/s/1AHb4mGCMHMhEG7uxw6SvcQ 提取码: x2yf 复制这段内容后打开百度网盘手机App，操作更方便哦
四、制作图片并转化为二进制文件
第一、电脑先截图或者制作一个240×240的图片（就是要放到esp32 240×240屏幕上显示的图片），此处我直接在网上下载了一个图片，并重命名为image.png。
第二、在电脑端通过python程序，将这个图片转换为一个二进制数据的文件（例如名字叫做image.dat）。这个文件有240×240个数据，但又因为240×240屏幕中每个像素点的颜色有2Byte组成，所以实际上的文件内容有240行每个240×2个数据，即240x240x2个数据。
转化代码如下：
# img_to_binary.py
import struct
import numpy as np
from PIL import Image # PIL就是pillow库
def color565(r, g, b):
return (r & 0xf8) << 8 | (g & 0xfc) << 3 | b >> 3
def main():
img = Image.open("image.png")
print(img.format, img.size, img.mode)
img_data = np.array(img) # 240行240列有3个 240x240x3
with open("image.dat", "wb") as f:
for line in img_data:
for dot in line:
f.write(struct.pack("H", color565(*dot))[::-1])
if __name__ == '__main__':
main()
此处问了方便，我是把图片、代码、二进制文件放在同一级目录下的：
六、将二进制文件传到开发板
实现方法：我们在开发板中开启一个TCP服务端，用来接收数据。然后在电脑上建立一个客户端，用来发送数据，这样我们就可以通过WIFI将二进制文件传送到开发板中了。
第一、使用Thonny在开发板中创建代码如下：
# recv_img_dat.py 在MicroPython上启动TCP服务器，接收数据
import time
import network
import machine
import socket
def do_connect():
wlan = network.WLAN(network.STA_IF)
wlan.active(True)
if not wlan.isconnected():
print('connecting to network...')
wlan.connect('WIFI名称', 'WIFI密码') # WIFI名称和密码
i = 1
while not wlan.isconnected():
print("正在链接...{}".format(i))
i += 1
time.sleep(1)
print('network config:', wlan.ifconfig())
# 0. 链接wifi
do_connect()
# 1. 创建TCP套接字
server_s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# 2. 绑定本地信息
server_s.bind(("", 8080))
# 3. 设置为被动的
server_s.listen(128)
print("等待对方链接...")
# 4. 等待客户端链接
new_s, client_info = server_s.accept()
print("等待对方发送图片数据...")
# 3. 创建文件，接收数据
with open("image.dat", "wb") as f:
for i in range(240):
# 3.1 接收数据
data = new_s.recv(480) # 240*2=480 一行有240个点，每个点有2个字节
# 3.2 写到文件
f.write(data)
print("接收第%d行" % (i+1))
print("接收完毕")
# 7. 关闭套接字
new_s.close()
server_s.close()
然后运行：
如上图，我们的开发板已经准备好接收数据了，我们看到开发板的IP地址是192.168.0.106（默认端口号是8080）
第二、在电脑上打开Pycharm，创建以下代码，用来发送二进制文件到开发板
# send_img_dat_to_esp.py 发送二进制文件到开发板中
from socket import *
# 1. 创建socket
tcp_client_socket = socket(AF_INET, SOCK_STREAM)
# 2. 链接服务器
tcp_client_socket.connect(("192.168.0.106", 8080)) # ESP32开发板的IP地址和端口号
# 2. 打开文件，发送数据
with open("image.dat", "rb") as f:
for i in range(240):
# 3.1 写到文件
data = f.read(480)
# 3.2 接收数据
tcp_client_socket.send(data) # 240*2=480 一行有240个点，每个点有2个字节
print("发送第%d行" % (i + 1))
# time.sleep(0.5)
print("发送完毕")
# 7. 关闭套接字
tcp_client_socket.close()
然后运行程序，我们看到发送数据完成即可：
第三、我们切换到Thonny IDE看到接收数据完成
然后我们就可以通过程序显示图片了。
六、显示图片代码
我们在显示钱需要先把屏幕驱动st7789_new.py导入到开发板中
驱动代码如下：
import ustruct
import utime
_NOP = const(0x00)
_SWRESET = const(0x01)
_RDDID = const(0x04)
_RDDST = const(0x09)
_SLPIN = const(0x10)
_SLPOUT = const(0x11)
_PTLON = const(0x12)
_NORON = const(0x13)
_INVOFF = const(0x20)
_INVON = const(0x21)
_DISPOFF = const(0x28)
_DISPON = const(0x29)
_CASET = const(0x2A)
_RASET = const(0x2B)
_RAMWR = const(0x2C)
_RAMRD = const(0x2E)
_PTLAR = const(0x30)
_COLMOD = const(0x3A)
_MADCTL = const(0x36)
_FRMCTR1 = const(0xB1)
_FRMCTR2 = const(0xB2)
_FRMCTR3 = const(0xB3)
_INVCTR = const(0xB4)
_DISSET5 = const(0xB6)
_GCTRL = const(0xB7)
_VCOMS = const(0xBB)
_FRCTR2 = const(0xC6)
_D6H = const(0xD6)
_PWCTRL1 = const(0xD0)
_GATECTRL = const(0xE4)
_PWCTR1 = const(0xC0)
_PWCTR2 = const(0xC1)
_PWCTR3 = const(0xC2)
_PWCTR4 = const(0xC3)
_PWCTR5 = const(0xC4)
_VMCTR1 = const(0xC5)
_RDID1 = const(0xDA)
_RDID2 = const(0xDB)
_RDID3 = const(0xDC)
_RDID4 = const(0xDD)
_PWCTR6 = const(0xFC)
_GMCTRP1 = const(0xE0)
_GMCTRN1 = const(0xE1)
def color565(r, g, b):
return (r & 0xf8) << 8 | (g & 0xfc) << 3 | b >> 3
class DummyPin:
"""A fake gpio pin for when you want to skip pins."""
OUT = 0
IN = 0
PULL_UP = 0
PULL_DOWN = 0
OPEN_DRAIN = 0
ALT = 0
ALT_OPEN_DRAIN = 0
LOW_POWER = 0
MED_POWER = 0
HIGH_PWER = 0
IRQ_FALLING = 0
IRQ_RISING = 0
IRQ_LOW_LEVEL = 0
IRQ_HIGH_LEVEL = 0
def __call__(self, *args, **kwargs):
return False
init = __call__
value = __call__
out_value = __call__
toggle = __call__
high = __call__
low = __call__
on = __call__
off = __call__
mode = __call__
pull = __call__
drive = __call__
irq = __call__
class Display:
_PAGE_SET = None
_COLUMN_SET = None
_RAM_WRITE = None
_RAM_READ = None
_INIT = ()
_ENCODE_PIXEL = ">H"
_ENCODE_POS = ">HH"
_DECODE_PIXEL = ">BBB"
def __init__(self, width, height):
self.width = width
self.height = height
self.init()
def init(self):
"""Run the initialization commands."""
for command, data in self._INIT:
self._write(command, data)
def _block(self, x0, y0, x1, y1, data=None):
"""Read or write a block of data."""
self._write(self._COLUMN_SET, self._encode_pos(x0, x1))
self._write(self._PAGE_SET, self._encode_pos(y0+80, y1+80))
if data is None:
size = ustruct.calcsize(self._DECODE_PIXEL)
return self._read(self._RAM_READ, (x1 - x0 + 1) * (y1 - y0 + 1) * size)
self._write(self._RAM_WRITE, data)
def _encode_pos(self, a, b):
"""Encode a postion into bytes."""
return ustruct.pack(self._ENCODE_POS, a, b)
def _encode_pixel(self, color):
"""Encode a pixel color into bytes."""
return ustruct.pack(self._ENCODE_PIXEL, color)
def _decode_pixel(self, data):
"""Decode bytes into a pixel color."""
return color565(*ustruct.unpack(self._DECODE_PIXEL, data))
def pixel(self, x, y, color=None):
"""Read or write a pixel."""
if color is None:
return self._decode_pixel(self._block(x, y, x, y))
if not 0 <= x < self.width or not 0 <= y < self.height:
return
self._block(x, y, x, y, self._encode_pixel(color))
def fill_rectangle(self, x, y, width, height, color):
"""Draw a filled rectangle."""
x = min(self.width - 1, max(0, x))
y = min(self.height - 1, max(0, y))
w = min(self.width - x, max(1, width))
h = min(self.height - y, max(1, height))
self._block(x, y, x + w - 1, y + h - 1, b'')
chunks, rest = divmod(w * h, 512)
print("color:", color)
pixel = self._encode_pixel(color)
print("decode:", pixel)
if chunks:
data = pixel * 512
for count in range(chunks):
self._write(None, data)
if rest:
self._write(None, pixel * rest)
def fill(self, color=0):
"""Fill whole screen."""
self.fill_rectangle(0, 0, self.width, self.height, color)
def hline(self, x, y, width, color):
"""Draw a horizontal line."""
self.fill_rectangle(x, y, width, 1, color)
def vline(self, x, y, height, color):
"""Draw a vertical line."""
self.fill_rectangle(x, y, 1, height, color)
def blit_buffer(self, buffer, x, y, width, height):
"""Copy pixels from a buffer."""
if (not 0 <= x < self.width or
not 0 <= y < self.height or
not 0 < x + width <= self.width or
not 0 < y + height <= self.height):
raise ValueError("out of bounds")
self._block(x, y, x + width - 1, y + height - 1, buffer)
class DisplaySPI(Display):
def __init__(self, spi, dc, cs=None, rst=None, width=1, height=1):
self.spi = spi
self.cs = cs
self.dc = dc
self.rst = rst
if self.rst is None:
self.rst = DummyPin()
if self.cs is None:
self.cs = DummyPin()
self.cs.init(self.cs.OUT, value=1)
self.dc.init(self.dc.OUT, value=0)
self.rst.init(self.rst.OUT, value=1)
self.reset()
super().__init__(width, height)
def reset(self):
self.rst(0)
utime.sleep_ms(50)
self.rst(1)
utime.sleep_ms(50)
def _write(self, command=None, data=None):
if command is not None:
self.dc(0)
self.cs(0)
self.spi.write(bytearray([command]))
self.cs(1)
if data:
self.dc(1)
self.cs(0)
self.spi.write(data)
self.cs(1)
def _read(self, command=None, count=0):
self.dc(0)
self.cs(0)
if command is not None:
self.spi.write(bytearray([command]))
if count:
data = self.spi.read(count)
self.cs(1)
return data
class ST7789(DisplaySPI):
"""
A simple driver for the ST7789-based displays.
>>> from machine import Pin, SPI
>>> import st7789
>>> display = st7789.ST7789(SPI(1), dc=Pin(12), cs=Pin(15), rst=Pin(16))
>>> display = st7789.ST7789R(SPI(1, baudrate=40000000), dc=Pin(12), cs=Pin(15), rst=Pin(16))
>>> display.fill(0x7521)
>>> display.pixel(64, 64, 0)
"""
_COLUMN_SET = _CASET
_PAGE_SET = _RASET
_RAM_WRITE = _RAMWR
_RAM_READ = _RAMRD
_INIT = (
(_SWRESET, None),
(_SLPOUT, None),
(_COLMOD, b"\x55"), # 16bit color
(_MADCTL, b"\x08"),
)
def __init__(self, spi, dc, cs, rst=None, width=240, height=240):
super().__init__(spi, dc, cs, rst, width, height)
def init(self):
super().init()
cols = ustruct.pack(">HH", 0, self.width)
rows = ustruct.pack(">HH", 0, self.height)
# ctr2p= ustruct.pack(">BBBBB", b"\x1F\x1F\x00\x33\x33")
ctr2p= b"\x1F\x1F\x00\x33\x33"
# ctr1p= ustruct.pack(">BB", b"\xA4\xA1")
ctr1p= b"\xA4\xA1"
# e0p= ustruct.pack(">BBBBBBBBBBBBBB", b"\xF0\x08\x0E\x09\x08\x04\x2F\x33\x45\x36\x13\x12\x2A\x2D")
e0p= b"\xF0\x08\x0E\x09\x08\x04\x2F\x33\x45\x36\x13\x12\x2A\x2D"
# e1p= ustruct.pack(">BBBBBBBBBBBBBB", b"\xF0\x0E\x12\x0C\x0A\x15\x2E\x32\x44\x39\x17\x18\x2B\x2F")
e1p= b"\xF0\x0E\x12\x0C\x0A\x15\x2E\x32\x44\x39\x17\x18\x2B\x2F"
# gatep= ustruct.pack(">BBB", b"\x1d\x00\x00")
gatep= b"\x1d\x00\x00"
for command, data in (
(_CASET, cols),
(_RASET, rows),
(_FRMCTR2,ctr2p),
(_GCTRL, b"\x00"),
(_VCOMS, b"\x36"),
(_PWCTR3, b"\x01"),
(_PWCTR4, b"\x13"),
(_PWCTR5, b"\x20"),
(_FRCTR2, b"\x13"),
(_D6H, b"\xA1"),
(_PWCTRL1, ctr1p),
(_GMCTRP1, e0p),
(_GMCTRN1, e1p),
(_GATECTRL, gatep),
(_INVON, None),
(_NORON, None),
(_DISPON, None),
(_MADCTL, b"\xc0"), # Set rotation to 0 and use RGB
):
self._write(command, data)
class ST7889_Image(ST7789):
def _set_columns(self, start, end):
if start <= end:
self._write(_CASET, self._encode_pos(start, end))
def _set_rows(self, start, end):
if start <= end:
self._write(_RASET, self._encode_pos(start, end))
def _set_window(self, x0, y0, x1, y1):
"""
x0： x起始位置
y0: y起始位置
x1: x结束位置
y1: y结束位置
"""
self._set_columns(x0, x1)
self._set_rows(y0, y1)
self._write(_RAMWR)
def show_img(self, x0, y0, x1, y1, img_data):
self._set_window(x0, y0 + 80, x1, y1 + 80)
self._write(None, img_data)
显示图片代码如下：
# show_img.py 显示图片代码
from machine import Pin, SPI
import st7789_new
tft = st7789_new.ST7889_Image(SPI(2, 60000000), dc=Pin(2), cs=Pin(5), rst=Pin(15))
tft.fill(st7789_new.color565(0, 0, 0)) # 背景设置为黑色
def show_img():
with open("image.dat", "rb") as f:
for row in range(240):
buffer = f.read(480)
tft.show_img(0, row, 239, row, buffer)
show_img()
七、显示效果
八、将所有文件和大家理一下
1，开发板中的文件
st7789_new.py + recv_img_dat.py + show_img.py + image.dat
2、电脑中的文件
image.png + send_img_dat_to_esp.py + image.dat
最后将所有文件打包分享给大家，链接如下：
链接: https://pan.baidu.com/s/1pQAeptN-esxvmERgAK9n-g 提取码: 23yd 复制这段内容后打开百度网盘手机App，操作更方便哦
