Difference between revisions of "7.5inch e-Paper HAT Manual"
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| Dimensions|| 7.5inch | | Dimensions|| 7.5inch | ||
|- style="background:#efefef; color:black;" align="center" | |- style="background:#efefef; color:black;" align="center" | ||
− | | Outline dimension (driver board) || | + | | Outline dimension (driver board) || 65.0mm × 30.2mm |
|- style="background:white; color:black;" align="center" | |- style="background:white; color:black;" align="center" | ||
| Display dimension || 163.2mm × 97.92mm | | Display dimension || 163.2mm × 97.92mm |
Revision as of 06:34, 10 November 2022
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Overview
Version Description
- V2: The resolution is 800 × 480. The hardware structure and interface of the V2 version are compatible with the V1 version and adopt the V2 program. If you are purchasing for the first time, and there is a V2 label on the back of the screen, you can directly use the V2 program.
- V1: The resolution is 640 × 384, using the V1 program. (More information can be found in the datasheet.)
Feature
Dimensions | 7.5inch |
Outline dimension (driver board) | 65.0mm × 30.2mm |
Display dimension | 163.2mm × 97.92mm |
Outline dimension (raw panel) | 170.2mm × 111.2mm × 1.18mm |
Outline dimension (screen) | 177.2mm × 118.2mm |
Operating voltage | 3.3V / 5V (Both power supply and signal need to be 5V.) |
Communication interface | SPI |
Dot pitch | 0.205mm × 0.204mm |
Resolution | 800 × 480 |
Display color | Black, White |
Grey scale | 2 |
Refresh time | 5s |
Refresh power | 26.4mW(typ.) |
Standby current | <0.01uA (close to 0) |
- Note:
- Refresh time: The refresh time is the experimental results, the actual refresh time will have errors, and the actual effect shall prevail. There will be a flickering effect during the global refresh process, this is a normal phenomenon.
- Power consumption: The power consumption data is the experimental results. The actual power consumption will have a certain error due to the existence of the driver board and the actual use situation. The actual effect shall prevail.
- Refresh time: The refresh time is the experimental results, the actual refresh time will have errors, and the actual effect shall prevail. There will be a flickering effect during the global refresh process, this is a normal phenomenon.
SPI Communication Timing
- CSB (CS): Slave chip select, when CS is low, the chip is enabled.
- SCL (SCK/SCLK): UART clock signal.
- D/C (DC): data/command control pin, writes commands in low level; writes data/parameter in high level.
- SDA (DIN): serial data signal.
- Timing: CPHL=0, CPOL=0 (SPI0)
【Remarks】For more information about SPI, you can search for information online.
Working principle
This product is an E-paper device adopting the image display technology of Microencapsulated Electrophoretic Display, MED. The initial approach is to create tiny spheres, in which the charged color pigments are suspended in the transparent oil and would move depending on the electronic charge. The E-paper screen display patterns by reflecting the ambient light, so it has no background light requirement. Under ambient light, the E-paper screen still has high visibility with a wide viewing angle of 180 degrees. It is the ideal choice for E-reading. (Note that the e-Paper cannot support updating directly under sunlight)
Pixel & Byte
We define the pixels in a monochrome picture, 0 is black and 1 is white.
White:□: Bit 1
Black:■: Bit 0
- The dot in the figure is called a pixel. As we know, 1 and 0 are used to define the color, therefore we can use one bit to define the color of one pixel, and 1 byte = 8pixels
- For example, If we set the first 8 pixels to black and the last 8 pixels to white, we show it by codes, they will be 16 bit as below:
For computer, the data is saved in MSB format:
So we can use two bytes for 16 pixels.
- 7.5inch e-Paper V2
The display principle is exactly the same as above.
- 7.5inch e-Paper V1
Precautions
- For E-paper displays that support partial refresh, please note that you cannot refresh them with the partial refresh mode all the time. After refreshing partially several times, you need to fully refresh EPD once. Otherwise, the display effect will be abnormal, which cannot be repaired!
- Note that the screen cannot be powered on for a long time. When the screen is not refreshed, please set the screen to sleep mode or power off it. Otherwise, the screen will remain in a high voltage state for a long time, which will damage the e-Paper and cannot be repaired!
- When using the e-Paper display, it is recommended that the refresh interval be at least 180s, and refresh at least once every 24 hours. If the e-Paper is not used for a long time, you should use the program to clear the screen before storing it. (Refer to the datasheet for specific storage environment requirements.)
- After the screen enters sleep mode, the sent image data will be ignored, and it can be refreshed normally only after initializing again.
- Control the 0x3C or 0x50 (refer to the datasheet for details) register to adjust the border color. In the demo, you can adjust the Border Waveform Control register or VCOM AND DATA INTERVAL SETTING to set the border.
- If you find that the created image data is displayed incorrectly on the screen, it is recommended to check whether the image size setting is correct, change the width and height settings of the image and try again.
- The working voltage of the e-Paper display is 3.3V. If you buy the raw panel and you need to add a level convert circuit for compatibility with 5V voltage. The new version of the driver board (V2.1 and subsequent versions) has added a level processing circuit, which can support both 3.3V and 5V. The old version only supports a 3.3V working environment. You can confirm the version before using it. (The one with the 20-pin chip on the PCB is generally the new version.)
- The FPC cable of the screen is relatively fragile, pay attention to bending the cable along the horizontal direction of the screen when using it, and do not bend the cable along the vertical direction of the screen.
- The screen of e-Paper is relatively fragile, please try to avoid dropping, bumping, and pressing hard.
- We recommend that customers use the sample program provided by us to test with the corresponding development board.
Working With Raspberry Pi
Hardware Connection
When connecting the Raspberry Pi, you can directly insert the board into the 40PIN pin header of the Raspberry Pi, and pay attention to the correct pins.
If you choose to connect with an 8PIN cable, please refer to the pin correspondence table below:
e-Paper | Raspberry Pi | |
BCM2835 | Board | |
VCC | 3.3V | 3.3V |
GND | GND | GND |
DIN | MOSI | 19 |
CLK | SCLK | 23 |
CS | CE0 | 24 |
DC | 25 | 22 |
RST | 17 | 11 |
BUSY | 24 | 18 |
Enable SPI Interface
- Open the Raspberry Pi terminal and enter the following command in the config interface:
sudo raspi-config Choose Interfacing Options -> SPI -> Yes Enable SPI interface
Then reboot your Raspberry Pi:
sudo reboot
- Check /boot/config.txt, and you can see 'dtparam=spi=on' was written in.
- To make sure SPI is not occupied, it is recommended to close other drivers' coverage. You can use ls /dev/spi* to check whether SPI is occupied. If the terminal outputs /dev/spidev0.1 and /dev/spidev0.1, SPI is not occupied.
C
- Install BCM2835
#Open the Raspberry Pi terminal and run the following command wget http://www.airspayce.com/mikem/bcm2835/bcm2835-1.71.tar.gz tar zxvf bcm2835-1.71.tar.gz cd bcm2835-1.71/ sudo ./configure && sudo make && sudo make check && sudo make install # For more information, please refer to the official website: http://www.airspayce.com/mikem/bcm2835/
- Install WiringPi (Optional)
#Open the Raspberry Pi terminal and run the following command: sudo apt-get install wiringpi #For Raspberry Pi systems after May 2019 (earlier than before, you may not need to execute), you may need to upgrade: wget https://project-downloads.drogon.net/wiringpi-latest.deb sudo dpkg -i wiringpi-latest.deb gpio -v #Run gpio -v and version 2.52 will appear. If it does not appear, the installation is wrong. #Bullseye branch system use the following command: git clone https://github.com/WiringPi/WiringPi cd WiringPi ./build gpio -v # Run gpio -v and version 2.60 will appear. If it does not appear, it means that there is an installation error.
- Download demo (You can skip this step if you have downloaded it.)
sudo apt-get install p7zip-full wget https://files.waveshare.com/upload/3/39/E-Paper_code.7z 7z x E-Paper_code.7z -O./e-Paper cd e-Paper/RaspberryPi_JetsonNano/
- Download the program via GitHub (alternate method, already downloaded can be skipped)
git clone https://github.com/waveshare/e-Paper.git cd e-Paper/RaspberryPi_JetsonNano/
- Compile the program (Note: -j4 is to compile with 4 threads, the numbers can be modified by yourself; EPD=epd5in83bV2 is to specify a macro definition, and epd5in83bV2 corresponds to the test program in the main function).
# Now at e-Paper/RaspberryPi_JetsonNano cd c sudo make clean sudo make -j4 EPD=epd5in83bV2
- Run the program
sudo ./epd
Python
- Install the function library
sudo apt-get update sudo apt-get install python3-pip sudo apt-get install python3-pil sudo apt-get install python3-numpy sudo pip3 install RPi.GPIO sudo pip3 install spidev
- Install function library (python2)
sudo apt-get update sudo apt-get install python-pip sudo apt-get install python-pil sudo apt-get install python-numpy sudo pip install RPi.GPIO sudo pip install spidev
- Download demo (You can skip this step if you have downloaded it.)
sudo apt-get install p7zip-full wget https://files.waveshare.com/upload/3/39/E-Paper_code.7z 7z x E-Paper_code.7z -O./e-Paper cd e-Paper/RaspberryPi_JetsonNano/
- Download the program via GitHub (alternate method, already downloaded can be skipped.)
git clone https://github.com/waveshare/e-Paper.git cd e-Paper/RaspberryPi_JetsonNano/
- Run the program
# Make sure it's in e-Paper/RaspberryPi_JetsonNano/ cd python/examples/ python3 epd_7in5_V2_test.py
Working With Arduino
Hardware Connection
Use an 8PIN cable to connect, please refer to the pin correspondence table below:
e-Paper | Arduino UNO | Mega2560 |
VCC | 5V | 5V |
GND | GND | GND |
DIN | D11 | D51 |
CLK | D13 | D52 |
CS | D10 | D10 |
DC | D9 | D9 |
RST | D8 | D8 |
BUSY | D7 | D7 |
Install IDE
Arduino IDE Windows Install Guide
Run The Program
- Download the program in Resource, unzip it to the "E-Paper_code" directory, and you can see the following content:
- Open the test program: E-Paper_code\Arduino\epd7in5_V2\epd7in5_V2.ino
- Select the corresponding Board and Port in the Tools in the Arduino IED.
- Finally, click upload, the upload is successful as follows (Arduino 1.8.13).
Working With Jetson Nano
Hardware Connection
The 40PIN pin of Jetson Nano is compatible with the 40PIN pin of Raspberry Pi and provides a Jetson.GPIO library with the same API as the RPI.GPIO library of Raspberry Pi, so the serial number connected here is the same as that of Raspberry Pi. The module can be directly inserted into the 40Pin headers of the Jetson Nano when using the 40PIN interface.
If you choose to connect with an 8PIN cable, please refer to the pin correspondence table below:
e-Paper | Jetson Nano Developer Kit | |
BCM2835 | Board | |
VCC | 3.3V | 3.3V |
GND | GND | GND |
DIN | 10 (SPI0_MOSI) | 19 |
CLK | 11 (SPI0_SCK) | 23 |
CS | 8 (SPI0_CS0) | 24 |
DC | 25 | 22 |
RST | 17 | 11 |
BUSY | 24 | 18 |
C
- Download the test demo: (you can skip this step if you have downloaded it.)
sudo apt-get install p7zip-full wget https://files.waveshare.com/upload/3/39/E-Paper_code.7z 7z x E-Paper_code.7z -O./e-Paper cd e-Paper/RaspberryPi_JetsonNano/
- Download the program via GitHub (alternate method, already downloaded can be skipped)
git clone https://github.com/waveshare/e-Paper.git cd e-Paper/RaspberryPi_JetsonNano/
- Compile program (Note: JETSON is the specified device, and RPI is not specified by default. -j4 is to compile by 4 threads, and the number can be changed by yourself. "EPD=epd7in5V2" is to specify a macro definition, and "epd7in5V2" corresponds to the test program in the main function.)
# Now at e-Paper/RaspberryPi_JetsonNano cd c sudo make clean sudo make JETSON -j4 EPD=epd7in5V2
- Run the program
sudo ./epd
Python
- Install function library
sudo apt-get update sudo apt-get install python3-numpy sudo apt-get install python3-pip sudo pip3 install Jetson.GPIO
- Download the program (you can skip this step if you have downloaded it.)
sudo apt-get install p7zip-full wget https://files.waveshare.com/upload/3/39/E-Paper_code.7z 7z x E-Paper_code.7z -O./e-Paper cd e-Paper/RaspberryPi_JetsonNano/
- Download the program via GitHub (alternate method, already downloaded can be skipped).
At present, accessing GitHub is not very smooth. It is recommended to use the above method to download from our official website.
git clone https://github.com/waveshare/e-Paper.git cd e-Paper/RaspberryPi_JetsonNano/
- Run the program
# Make sure it's in e-Paper/RaspberryPi_JetsonNano/ cd python/examples/ python3 epd_7in5_V2_test.py
Working With Sunrise X3 Pi
Hardware Connection
When connecting the Sunrise X3 Pi, you can directly insert the board into the 40PIN pin header of the Sunrise X3 Pi, and pay attention to the correct pins.
If you choose to connect with an 8PIN cable, please refer to the pin correspondence table below:
e-Paper | Sunrise X3 Pi | |
BCM | Board | |
VCC | 3.3V | 3.3V |
GND | GND | GND |
DIN | MOSI | 19 |
CLK | SCLK | 23 |
CS | CE0 | 24 |
DC | 25 | 22 |
RST | 17 | 11 |
BUSY | 24 | 18 |
Enable SPI
- SPI is enabled by default. If you have disabled it, you can enable it by following the steps below.
- Enter the command: sudo srpi-config
Python
- The corresponding library has been installed in the function. If you uninstall it accidentally, please use the following command to install it.
sudo apt-get update sudo apt-get install python-pip sudo apt-get install python-pil sudo apt-get install python-numpy sudo pip install Hobot.GPIO sudo pip install spidev
- Download the program (skip this step if you have downloaded it).
sudo apt-get install p7zip-full wget https://files.waveshare.com/upload/3/39/E-Paper_code.7z 7z x E-Paper_code.7z -O./e-Paper cd e-Paper/RaspberryPi_JetsonNano/
- Download the program via GitHub (alternate method, already downloaded can be skipped)
git clone https://github.com/waveshare/e-Paper.git cd e-Paper/RaspberryPi_JetsonNano/
- Run the program
# Make sure you are in e-Paper/RaspberryPi_JetsonNano/ cd python/examples/ python3 epd_7in5_V2_test.py
Working With STM32
Hardware Connection
e-Paper | STM32 |
VCC | 3.3V |
GND | GND |
DIN | PA7 |
CLK | PA5 |
CS | PA4 |
DC | PA2 |
RST | PA1 |
BUSY | PA3 |
Run The Program
- Click to download the program, and then unzip it into the E-Paper_code directory to see the following content.
- Use Keil to open epd-demo.uvprojx in the E-Paper_code\STM32\STM32-F103ZET6\MDK-ARM directory
- Open Keil's compilation toolbar (usually already open).
- Select the EPD_7in5_V2_test at the location shown in the picture.
- Click to compile.
- Make sure the appropriate programmer is connected, then click LOAD to download the program to the microcontroller.
Resources
Documentation
Demo code
Datasheets
Development Resources
FAQ
Question about Software
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1. First check whether the wiring is correct.
2. Check whether the spi is turned on and whether the parameters are configured correctly (spi baud rate, spi mode, and other parameters).
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Question about Hardware
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- The rated input voltage of the ink screen is 2.3~3.6V. If it is a 5V system, level conversion is required. In addition, the voltage should not be lower than 2.5V, so as not to affect the display effect of the e-paper screen.
- Device selection can use the model in the schematic diagram we provide or choose according to the data sheet.
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- Check if SPI communication is normal.
- Confirm whether the BUSY pin is normally initialized to input mode.
- It may be that there is no normal reset, try to shorten the duration of the low level during reset (because the power-off switch is added to the drive circuit, the reset low level is too long, which will cause the drive board to power off and cause the reset to fail).
- If the busy function sends the 0x71 command, you can try to comment it out.
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- 0.5mm pitch, 24Pin.
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Question about Screen
- 【Working conditions】Temperature range: 0~50°C; Humidity range: 35%~65%RH.
- 【Storage conditions】Temperature range: below 30°C; Humidity range: below 55%RH; Maximum storage time: 6 months.
- 【Transportation conditions】Temperature range: -25~70°C; Maximum transportation time: 10 days.
- 【After unpacking】Temperature range: 20°C±5°C; Humidity range: 50±5%RH; Maximum storage time: Assemble within 72 hours.
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- refresh mode
- Full refresh: The electronic ink screen will flicker several times during the refresh process (the number of flickers depends on the refresh time), and the flicker is to remove the afterimage to achieve the best display effect.
- Bureau brush: The electronic ink screen has no flickering effect during the refresh process. Users who use the partial brushing function note that after refreshing several times, a full brush operation should be performed to remove the residual image, otherwise the residual image problem will become more and more serious, or even damage the screen (currently only some black and white e-ink screens support partial brushing, please refer to product page description).
- refresh rate
- During use, it is recommended that customers set the refresh interval of the e-ink screen to at least 180 seconds (except for products that support the local brush function).
- During the standby process (that is, after the refresh operation), it is recommended that the customer set the e-ink screen to sleep mode, or power off (the power supply part of the ink screen can be disconnected with an analog switch) to reduce power consumption and prolong the life of the e-ink screen. (If some e-ink screens are powered on for a long time, the screen will be damaged beyond repair.)
- During the use of the three-color e-ink screen, it is recommended that customers update the display screen at least once every 24 hours (if the screen remains the same screen for a long time, the screen burn will be difficult to repair).
- Full refresh: The electronic ink screen will flicker several times during the refresh process (the number of flickers depends on the refresh time), and the flicker is to remove the afterimage to achieve the best display effect.
- Application
- The e-ink screen is recommended for indoor use. If it is used outdoors, it is necessary to avoid direct sunlight on the e-ink screen, and at the same time, take UV protection measures, because charged particles will dry out under strong light for a long time, resulting in loss of activity and failure to refresh. This situation is irreversible. When designing e-ink screen products, customers should pay attention to determining whether the use environment meets the requirements of the e-paper screen.
- The e-ink screen is recommended for indoor use. If it is used outdoors, it is necessary to avoid direct sunlight on the e-ink screen, and at the same time, take UV protection measures, because charged particles will dry out under strong light for a long time, resulting in loss of activity and failure to refresh. This situation is irreversible. When designing e-ink screen products, customers should pay attention to determining whether the use environment meets the requirements of the e-paper screen.
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Insufficient or unstable power supply leads to data loss.
The data cable is too long to cause data loss, the extension cable should not exceed 20cm.
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Different batches of e-paper diaphragms and electrophoretic matrices require different voltage values when driving the display due to materials, manufacturing processes, etc. The waveform of the e-ink screen is reflected in the relationship between grayscale, voltage, and temperature. Generally speaking, after each batch of electrophoresis matrix is generated, there will be a corresponding waveform file in the form of a .wbf file. The film manufacturer will provide the waveform file and electrophoresis matrix to the manufacturer of the electronic paper screen, and then the manufacturer of the electronic paper screen integrates the protection board, substrate, and driver and then provides it to customers; if the waveform file does not correspond to the screen, it is likely that the display cannot be displayed or the display effect is unsatisfactory. Generally, the waveform file has OTP built into the driver IC of the ink screen when leaving the factory, and some programs we provide also call external waveform files to drive the e-ink screen.
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Support
If you require technical support, please go to the Support page and open a ticket.