Waveshare Pico e-Paper 2.13 V4 2.13inch E-Paper E-Ink Display Module User Guide

Waveshare Pico e-Paper 2.13 V4 2.13inch E-Paper E-Ink Display Module

Overview

2.13inch EPD (Electronic Paper Display) Module For Raspberry Pi Pico, 250 × 122 Pixels, Black / White, SPI Interface.

Version

• V4 is completely compatible with V3 and has its own demo that supports the fast refreshing function.

Feature

• Dimension: 2.13inch
• Operating voltage : 3.3V
• Outline dimensions (raw panel): 59.2mm x 29.2mm x 1.05mm
• Outline dimension : 65.00mm x 30.50mm
• Display size : 48.55 x 23.71mm
• Interface : SPI
• Dot pitch : 0.194 x 0.194mm
• Resolution : 250 x 122 pixels
• Display color : Black, white
• Greyscale : 2
• Partial refresh time : 0.3s
• full refresh time : 2s
• Refresh power : 26.4mW (typ.)
• Standby current : <0.01uA (almost none)

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.

SPI Communication Timing

Since the ink screen only needs to be displayed, the data cable (MISO) sent from the machine and received by the host is hidden here.

• CS: Slave chip select, when CS is low, the chip is enabled
• DC: data/command control pin, write command when DC=0; write data when DC=1
• SCLK: SPI communication clock
• SDIN: SPI communication master sends, the slave receives
• Timing: CPHL=0, CPOL=0 (SPI0)

[Remarks] For specific information about SPI, you can search for information online.

Working Protocol
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 displays patterns by reflecting the ambient light, so it has no background light requirement. (Note that the e- Paper cannot support updating directly under sunlight).

How to define pixels
In a monochrome picture we define the pixels, 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:

Precautions

1. 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!
2. It is a normal phenomenon that the three-color EPD will have a certain color difference in different batches. Hence, It is recommended to use the program to clear all the pictures on the EPD and store it facing up. Please clear the screen several times before powering on.
3. 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!
4. 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.)
5. After the screen enters sleep mode, the sent image data will be ignored, and it can be refreshed normally only after initializing again.
6. 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.
7. 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.
8. 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.)
9. 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.
10. The screen of e-Paper is relatively fragile, please try to avoid dropping, bumping, and pressing hard.
11. We recommend that customers use the sample program provided by us to test with the corresponding development board.

RPi Pico

Hardware Connection
Please take care of the direction when connecting Pico. A logo of the USB port is printed to indicate the directory, you can also check the pins. If you want to connect the board by an 8-pin cable, you can refer to the table below:

You can just attach the board to Pico like the Pico-ePaper-7.5.

Setup Environment

You can refer to the guides for Raspberry Pi: https://www.raspberrypi.org/documentation/pico/gettingstarted/

Download Demo codes
Open a terminal of Pi and run the following command:

You can also clone the codes from Github.

About the examples
The guides are based on Raspberry Pi.

C codes
The example provided is compatible with several types, you need to modify the main.c file, uncomment the definition according to the actual type of display you get. For example, if you have the Pico-ePaper-2.13, please modify the main.c file, uncomment line 18 (or maybe it is line 19).

Set the project:

Create a build folder and add the SDK. ../../pico-sdk is the default path of the SDK, if you save the SDK to other directories, please change it to the actual path.

Run cmake command to generate a Makefile file.

Run the command make to compile the codes.

• After compiling, the epd.uf2 file is generated. Next, press and hold the BOOTSEL button on the Pico board, connect the Pico to the Raspberry Pi using the Micro USB cable, and release the button. At this point, the device will recognize a removable disk (RPI-RP2).
• Copy the epd.uf2 file just generated to the newly recognized removable disk (RPI-RP2), Pico will automatically restart the running program.

Python

• First press and hold the BOOTSEL button on the Pico board, use the Micro USB cable to connect the Pico to the Raspberry Pi, then release the button. At this point, the device will recognize a removable disk (RPIRP2).
• Copy the rp2-pico-20210418-v1.15.uf2 file in the python directory to the removable disk (RPI-RP2) just identified.
• Update Thonny IDE.
• Open Thonny IDE (click on the Raspberry logo -> Programming -> Thonny Python IDE ), and select the interpreter:
  • Select Tools -> Options… -> Interpreter.
  • Select MicroPython (Raspberry Pi Pico and ttyACM0 port).
• Open the Pico_ePaper-xxx.py file in Thonny IDE, then run the current script (click the green triangle).

C Code Analysis

Bottom Hardware Interface
We package the hardware layer for easily porting to the different hardware platforms. DEV_Config.c(.h) in the directory: Pico_ePaper_Code\c\lib\Config.

• Data type:

• Module initialize and exit:
• GPIO Write/Read:
• SPI transmits data:

EPD driver
The driver codes of EPD are saved in the directory: Pico_ePaper_Code\c\lib\e-Paper Open the .h header file, and you can check all the functions defined.

• Initialize e-Paper, this function is always used at the beginning and after waking up the display.

xxx should be changed by the type of e-Paper, For example, if you use 2.13inch e-Paper (D), to fully update, it should be EPD_2IN13D_Init(0) and EPD_2IN13D_Init(1) for the partial update;

• Clear: this function is used to clear the display to white.

xxx should be changed by the type of e-Paper, For example, if you use 2.9inch e-Paper (D), it should be EPD_2IN9D_Clear();

• Send the image data (one frame) to EPD and display

There are several types which are different from others

• Enter sleep mode

Note, You should only hardware reset or use initialize function to wake up e-Paper from sleep mode xxx is the type of e-Paper, for example, if you use 2.13inch e-Paper D, it should be EPD_2IN13D_Sleep().

Application Programming Interface
We provide basic GUI functions for testing, like draw point, line, string, and so on. The GUI function can be found in the directory: RaspberryPi_JetsonNano\c\lib\GUI\GUI_Paint.c(.h).

The fonts used can be found in the directory: RaspberryPi_JetsonNano\c\lib\Fonts.

Create a new image, you can set the image name, width, height, rotate angle, and color.

Select image buffer: You can create multiple image buffers at the same time and select a certain one and draw by this function.

Rotate image: You need to set the rotation angle of the image, this function should be used after Paint_SelectImage(). The angle can be 0, 90, 180, or 270 .

【Note】After rotating, the place of the first pixel is different, we take a 1.54-inch e-paper as an example.

Image mirror: This function is used to set the image mirror.

Set the position and color of pixels: This is the basic function of GUI, it is used to set the position and color of a pixel in the buffer.

Clear display: To set the color of the image, this function always be used to clear the display.

Color of the windows: This function is used to set the color of windows, it is always used for updating partial areas like displaying a clock.

Draw point : Draw a point at the position （X point, Y point） of the image buffer, you can configure the color, size, and style.

Draw the line: Draw a line from (Xstart, Ystart) to (Xend, Yend) in the image buffer, you can configure the color, width, and style.

Draw a rectangle: Draw a rectangle from (Xstart, Ystart) to (Xend, Yend), you can configure the color, width, and style.

Draw circle: Draw a circle in the image buffer, use (X_Center Y_Center) as the center and Radius as the radius. You can configure the color, width of the line, and the style of the circle.

Show Ascii character: Show a character in (Xstart, Ystart) position, you can configure the font, foreground, and background.

Draw the string: Draw the string at (Xstart Ystart), you can configure the fonts, foreground, and the background

Draw Chinese string: Draw the Chinese string at (Xstart Ystart) of the image buffer. You can configure fonts (GB2312), foreground, and background .

Draw number: Draw numbers at (Xstart Ystart) of the image buffer. You can select font, foreground, and background.

Display time: Display time at (Xstart Ystart) of the image buffer, you can configure fonts, foreground, and background. This function is used for partial updating. Note that some of the e-Paper don’t support partial updates and you cannot use partial updates all the time, which will have ghost problems and destroy the display.

Resource

Document

• Schematic
• 2.13inch e-Paper Specification V4 （Newest）
• 2.13inch e-Paper Specification V3
• 2.13inch e-Paper Specification V2

Demo codes

• Demo codes
• Github link

Development Software

• Thonny Python IDE (Windows V3.3.3)
• Zimo221.7z
• Image2Lcd.7z

Pico Quick Start

Download Firmware

• MicroPython Firmware Download
• C_Blink Firmware Download
  • [Expand]

Video Tutorial

Pico Tutorial I – Basic Introduction

• Pico Tutorial II – GPIO
  • [Expand]
• Pico Tutorial III – PWM
  • [Expand]
• Pico Tutorial IV – ADC
  • [Expand]
• Pico Tutorial V – UART
  • [Expand]
• Pico Tutorial VI – To be continued…
  • [Expand]

MicroPython Series

• 【MicroPython】 machine.Pin Function
• 【MicroPython】 machine.PWM Function
• 【MicroPython】 machine.ADC Function
• 【MicroPython】 machine.UART Function
• 【MicroPython】 machine.I2C Function
• 【MicroPython】 machine.SPI Function
• 【MicroPython】 rp2.StateMachine

C/C++ Series

• 【C/C++】 Windows Tutorial 1 – Environment Setting
• 【C/C++】 Windows Tutorial 1 – Create New Project

Arduino IDE Series

Install Arduino IDE

1. Download the Arduino IDE installation package from the Arduino website .

Just click on “JUST DOWNLOAD”.

Click to install after downloading.

Note: You will be prompted to install the driver during the installation process, we can click Install.

Install Arduino-Pico Core on Arduino IDE

1. Open Arduino IDE, click the File on the left corner, and choose “Preferences”.
2. Add the following link in the additional development board manager URL, then click OK.

Note: If you already have the ESP8266 board URL, you can separate the URLs with commas like this:

Click on Tools -> Dev Board -> Dev Board Manager -> Search for pico, it shows installed since my computer has already installed it.

Upload Demo At the First Time

1. Press and hold the BOOTSET button on the Pico board, connect the Pico to the USB port of the computer via the Micro USB cable, and release the button when the computer recognizes a removable hard drive (RPI-RP2).
2. Download the demo, open the arduino\PWM\D1-LED path under the D1-LED.ino.
3. Click Tools -> Port, remember the existing COM, do not need to click this COM (different computers show different COM, so remember the existing COM on your computer).
4. Connect the driver board to the computer with a USB cable, then click Tools -> Ports, select uf2 Board for the first connection, and after the upload is complete, connecting again will result in an additional COM port.
5. Click Tool -> Dev Board -> Raspberry Pi Pico/RP2040 -> Raspberry Pi Pico.
6. After setting, click the right arrow to upload.
   • If you encounter problems during the period, you need to reinstall or replace the Arduino IDE version, uninstall the Arduino IDE needs to be uninstalled cleanly, after uninstalling the software you need to manually delete all the contents of the folder C:\Users\ [name]\AppData\Local\Arduino15 (you need to show the hidden files in order to see it) and then reinstall.

Pico-W Series Tutorial (To be continued…)

Open Source Demo

• MicroPython Demo (GitHub)
• MicroPython Firmware/Blink Demo (C)
• Official Raspberry Pi C/C++ Demo
• Official Raspberry Pi MicroPython Demo
• Arduino Official C/C++ Demo

FAQ

Question:What is the usage environment of the e-ink screen?

Answer:

• 【Operating 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.
• 【Transport 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.

Question:Precautions for e-ink screen refresh?

Answer:

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.
• Partial refresh: 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 operation (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).

Usage scenarios
The e-ink screen is recommended for indoor use. If you use it outdoors, you need to avoid direct sunlight on the e-ink screen and take UV protection measures at the same time. When designing e-ink screen products, customers should pay attention to determining whether the use environment meets the temperature and humidity requirements of the e-ink screen.

Question: Chinese cannot be displayed on the e-ink screen?

Answer:
The Chinese character library of our routine uses the GB2312 encoding method, please change your xxx_test.c file to GB2312 encoding format, compile and download it, and then it can be displayed normally.

Question: After using it for some time, the screen refresh (full refresh) has a serious afterimage problem that cannot be repaired.

Answer:
Power on the development board for a long time, after each refresh operation, it is recommended to set the screen to sleep mode or directly power off processing, otherwise, the screen may burn out when the screen is in a high voltage state for a long time.

Question: e-Paper show a black border?
Answer:
The border display color can be set through the Border Waveform Control register or the VCOM AND DATA INTERVAL SETTING register.

Question: What is the specification of the screen cable interface?

Answer:
0.5mm pitch, 24Pin.

• In this case, the customer needs to reduce the position of the round brush and clear the screen after 5 rounds of brushing (increasing the voltage of VCOM can improve the color, but it will increase the afterimage).

Question: After the ink screen enters deep sleep mode, can it be refreshed again?
Answer: Yes, but you need to re-initialize the electronic paper with software.

Question: When the 2.9-inch EPD is in deep sleep mode, the first time it wakes up, the screen refresh will be unclean. How can I solve it?

Answer:
The process of re-awakening the e-ink screen is the process of re-powering on, so when the EPD wakes up, the screen must be cleared first, to avoid the afterimage phenomenon to the greatest extent.

Question: Are bare-screen products shipped with a surface coating?
Answer: with film.

Question: Does the e-paper have a built-in temperature sensor?
Answer:
Yes, you can also use the IIC pin external LM75 temperature sensor.

Question: When testing the program, the program keeps stuck on an e-paper busy.

Answer:
It may be caused by the unsuccessful spi driver 1. Check whether the wiring is correct 2. Check whether the spi is turned on and whether the parameters are configured correctly (spi baud rate, spin mode, and other parameters).

Question: What is the refresh rate/lifetime of this e-ink screen?

Answer:
Ideally, with normal use, it can be refreshed 1,000,000 times (1 million times).

Support

Technical Support
If you need technical support or have any feedback/review, please click the Submit Now button to submit a ticket, Our support team will check and reply to you within 1 to 2 working days. Please be patient as we make every effort to help you to resolve the issue. Working Time: 9 AM – 6 AM GMT+8 (Monday to Friday)

References

• dl.espressif.com/dl/package_esp32_index.json
• GitHub - waveshareteam/Pico_ePaper_Code: Waveshrae Pico e-Paper driver code

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