【Weixue RP2040 dual-core development board】 Four ways to display five pictures
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Image display 4 ways
material:
图片显示2.docx
(2 MB, downloads: 7)
Image2Lcd2.9.zip
(513.02 KB, downloads: 4)
Python.rar
(446.12 KB, downloads: 6)
We have talked a lot about theory before. Now let’s do some practical work.
- The simplest way to display images
1. Use image acquisition software to obtain image dot matrix data
2. Image display effect, single-color display image 90*90
3. The program uses Weixue's official LCDDome, and adding the following code makes the operation simple and effective. . .
4. framebuf.MONO_HLSB frame buffer operation is as follows
https://docs.singtown.com/micropython/zh/latest/openmvcam/library/framebuf.html
But the memory of Pico is too small, and the monochrome 240*240 images cannot be loaded into it all at once.
A monochrome image requires 37k of cache consumption, but Micropico has only 19k of cache left. The chip cache is around 256k, and the rest of the memory should be consumed by the C program and interpreter, so the image size is changed to 90*90, so that the refresh speed is fast.
- Weixue code data, add the screenshot code above to achieve
This time, we generate dot matrix data from the image and store the dot matrix data in the internal program cache. Due to the limitation of internal cache space, the color image is further reduced in size.
1. The parameter configuration of the dot matrix software is shown in the figure
The hexadecimal dot matrix data generated by this tool software can be stored in the internal cache.
- Main code
The main code refers to the necessary code except LCDdome
Pattern =[ ] #Store the generated dot matrix data in the brackets
#The following 32, 32 is the x, y size of the image RGB565 encoding method
buf = framebuf.FrameBuffer(bytearray(pattern), 32, 32, framebuf.RGB565)# RGB565
# MONO_HLSB MONO_VLSB
# Load the processed pixels
LCD.blit(buf,90,90,LCD.white)
#print(byteModehex)
# Display the loaded data
LCD.show()
3. The display effect is as shown in the figure
- Color image display (external flash storage image information)
- Software Configuration
Two pictures are set here. Due to the pixel color saturation, the display effect of the first picture is not good.
- Actual display effect
- Video of the actual image refresh process
Since the internal cache space is limited and the dot matrix data needs to be decoded and re-encoded, the refresh speed is very slow. If the C language is used for development, the refresh speed will be doubled, because the C language does not need more operations. Just like the smooth display of the last image.
一次性刷新
- Dot matrix document production
4.1. The code generated by img2LCD software is in C language, and the generated dot matrix data is as follows
4.2. When the micropython program uses file = open("huawei.txt",'r'); to read the txt file, it gets a string, and the string contains carriage return and line feed\r\n. So for the convenience of operation, I re-edited the dot matrix data with vscode, removed 0x, and created a new txt document to store the processed dot matrix code in it. As shown in the figure
5. Import the Txt document into pico
6. Main code
#LCD.fill_rect(0,0,240,240,0)
file = open("huawei.txt",'r');
#file = open("maliao.txt",'r');
j = 0
while j<19:
# Due to cache space limitations, all data cannot be loaded into the cache at once, so the current design loads 5 lines of dot matrix data at a time and scans 19 times to display the image
byteModehex = bytearray(960)
#Create a new hexadecimal buffer array and apply for space
offset = 2040*j
#Offset the image to display five lines at a time 96*5 Because RGB565 takes 2 bytes, 5 lines need 96*5*2. The main dot matrix data is 960 bytes
# Because the data in the txt file is a character line, which is actually two characters in a hexadecimal format, 96*5*2*2=1920. This is the valid data that needs to be obtained from the txt file.
# But when reading a txt file, there are carriage return and line feed characters inside, and there are 32 characters in a line. In addition, there are 2 characters after each line (\r\n), so 1920/32*34 = 2040
file.seek(offset,0)
i = 0
huan = 0
#file.seek(960,0)
while i<960: # effective data of dot matrix is 960 bytes
#The main reason for the full display of the image is again that too much judgment and calculation consumes the chip operation cycle
patten = file.read(2) # readline # read # readlines
if patten[0] =='\r' or patten[0] =='\n': # Prevent cached data from getting \r\n and affecting dot matrix dislocation
#print('newline')
huan = huan+1
else :
# Convert the character to the high 4 digits of hexadecimal
if patten[0] >='A' or patten[0] <='F':
num = ord(patten[0]) - ord('A') +10
elif patten[0] >='0' or patten[0] <='9':
num = ord(patten[0]) - ord('0') +10
# Convert the character to the lower 4 bits of hexadecimal
if patten[1] >='A'or patten[1] <='F':
num1 = ord(patten[1]) - ord('A') +10
elif patten[1] >='0'or patten[1] <='9':
num1 = ord(patten[1]) - ord('0') +10
#The fourth bit of the high four bits forms a byte
number = num*16+num1
#Store valid data into the cache array in sequence
byteModehex = number
i = i+1
#patbuf = patten.strip().split()
#time.sleep(0.01) # Delay
#print(byteModehex)
#print(pattern)
#print("huan",huan)
#print(offset)
#The y axis gradually refreshes downward
y = 70 + j*5
#Use frame buffer to standardize RGB display pixels one by one
buf = framebuf.FrameBuffer(bytearray(byteModehex), 96, 5, framebuf.RGB565)# RGB565 # MONO_HLSB MONO_VLSB
LCD.blit(buf, 70, y,LCD.white)
#print(byteModehex)
#LCD.show() # This bit refreshes every 5 lines and the video phenomenon is always the same
j = j+1
LCD.show() #Refresh at this position. Multiple data is passed to the LCD, but it is not displayed. After the initial transmission, it is refreshed uniformly. Data loading still consumes time, but the refresh is not stuck. Refreshing in seconds is a common method for LCD display.
file.close() #The third step is to close the refrigerator door, otherwise the elephant may run away
- Update firmware version image display
https://bbs.eeworld.com.cn/thread-1227388-1-1.htmlFor details, please refer to this link, which is more detailed and better.
Firmware code download link
- Firmware Update
First, update the firmware, because the Weixue firmware does not have a picture display function, only an LCD display with basic functions.
- Download the picture to Pico, right-click on the picture in Thonny and upload it.
The image is used. Bmp image pixel size is 240*240 Any image can be
3. The example code display effect is great
'''
jpg.py
Draw a full screen jpg using the slower but less memory intensive method
of blitting each Minimum Coded Unit (MCU) block. Usually 8×8 pixels but can
be other multiples of 8.
GC9A01 display connected to a Raspberry Pi Pico.
Pico Pin Display
========= =======
14 (GP10) BL
15 (GP11) RST
16 (GP12) DC
17 (GP13) CS
18 (GND) GND
19 (GP14) CLK
20 (GP15) DIN
bigbuckbunny.jpg (c) copyright 2008, Blender Foundation / www.bigbuckbunny.org
'''
import gc
import time
from machine import Pin, SPI
import gc9a01
gc.enable()
gc.collect()
def main():
'''
Decode and draw jpg on display
'''
spi = SPI(1, baudrate=60000000, sck=Pin(10), mosi=Pin(11))
tft = gc9a01.GC9A01(
spi,
240,
240,
reset=Pin(12, Pin.OUT),
cs=Pin(9, Pin.OUT),
dc=Pin(8, Pin.OUT),
backlight=Pin(25, Pin.OUT),
rotation=0)
# enable display and clear screen
tft.init()
# cycle thru jpg's
while True:
for image in ["bigbuckbunny.jpg", "bluemarble.jpg"]:
tft.jpg(image, 0, 0, gc9a01.SLOW)
time.sleep(5)
main()
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