视频学习链接: https://www.bilibili.com/video/BV1G34y1E7tE?p=11&vd_source=b91967c499b23106586d7aa35af46413
讲义链接:https://doc.itprojects.cn/0006.zhishi.esp32/02.doc/index.html#/11.240x240image
链接: https://doc.itprojects.cn/0006.zhishi.esp32/01.download/st7789_itprojects.py
代码也粘贴在这:
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)
_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)
for command, data in (
(_CASET, cols),
(_RASET, rows),
(_INVON, None),
(_NORON, None),
(_DISPON, None),
(_MADCTL, b"\xc0"), # Set rotation to 0 and use RGB
):
self._write(command, data)
class ST7789_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)
(个人认为,这两个库结合的并不彻底,在显示一些更复杂的功能时,还是使用两个库(上节课的方法)来进行驱动。因为这个库只是在st7789.py的基础上增加了显示图片的功能(比如用来演示上节课旋转的功能时就不行),另外说下,我的液晶屏用这种不能行。)
下面,还是使用两种相结合的方式(经过实验,确实第一个驱动不能去掉,否则屏幕不刷新显示)来显示图片。
我是这样做的,首先保留 st7789.py 这个文件,其次,修改 st7789py.py 这个文件,修改的方法也很简单,也是参考视频中的程序内容做的。就是在后面重新定义了一个显示图片的函数。
def show_img(self, x0, y0, x1, y1, img_data):
self._set_window(x0, y0, x1, y1)
self._write(None, img_data)
解决了驱动的问题后,就是解决图片的问题。
我所使用的液晶屏的大小为 135 (宽、列、垂直) x 240(长、行、水平)。
截图后,使用画图软件调整大小,这里调整为(125 x 225)
在电脑端运行 python 程序,将该图片转换为一个二进制数据的文件。该视频中也提供了代码。
import struct
import numpy as np
from PIL import Image
def color565(r, g, b):
return (r & 0xf8) << 8 | (g & 0xfc) << 3 | b >> 3
def main():
img = Image.open("test1.png")
print(img.format, img.size, img.mode)
img_data = np.array(img) # 225行125列有3个 225x125x3
with open("text_img.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()
再之后,就是要把转换好的 .dat 文件传给 ESP32,这是使用无线局域网的传输方式。首先在 ESP32 端运行接收代码(连接到 WiFi 后把自己的 ip 地址告诉给电脑),然后在电脑端运行发送代码。
接收端代码:
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('ChinaNet-SAD8JJ', '13xxxxxx13')
i = 1
while not wlan.isconnected():
print("正在链接...{}".format(i))
i += 1
time.sleep(1)
print('network config:', wlan.ifconfig())
# 0. 连接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("text_img.dat".format(i), "wb") as f:
for j in range(225):
# 3.1 接收数据
data = new_s.recv(250) # 125*2=250 一行有125个点, 每个点有两个字节
# 3.2 写到文件
f.write(data)
# print("接收第%d行" % (j+1))
print("接收完毕".)
# 7. 关闭套接字
new_s.close()
server_s.close()
发送端代码:
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(("192.168.2.88", 8080))
# 2. 打开文件,发送数据
with open("text_img.dat", "rb") as f:
for j in range(225):
# 3.1 写到文件
data = f.read(250)
# 3.2 接收数据
tcp_client_socket.send(data) # 125*2=250 一行有125个点, 每个点有两个字节
# print("发送第%d行" % (j + 1))
# time.sleep(0.5)
print("发送完毕.")
# 7. 关闭套接字
tcp_client_socket.close()
最后,显示图片,代码如下:
import random
from machine import Pin, SPI
import st7789
import st7789py
# 解决第1次启动时,不亮的问题
st7789.ST7789(SPI(2, 80000000), dc=Pin(2), cs=Pin(5), rst=Pin(15))
# 创建显示屏对象
tft = st7789py.ST7789(SPI(2, 10000000), 135, 240, reset=Pin(15), dc=Pin(2), cs=Pin(5), rotation=0)
# 屏幕显示黑色
tft.fill(st7789py.color565(0, 0, 0))#RGB
def show_img():
with open("text_img.dat", "rb") as f:
for row in range(225):
buffer = f.read(250)
tft.show_img(0, row, 124, row, buffer) #起点坐标(0, row),终点坐标(124, row)
show_img()