Difference between revisions of "Template:E-paper Hat FAQ"

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==Question about Software==
 
==Question about Software==
 +
<div class="mw-collapsible-content">
 
{{FAQ|stm32 drives the ink screen, the MDK compilation display space is not enough?
 
{{FAQ|stm32 drives the ink screen, the MDK compilation display space is not enough?
 
|*Our demo uses stm32f103zet6. If the customer modifies other models in MDK, such as stm32f103rbt6, the ram space becomes smaller, and the stack size and heap size in the startup file need to be modified on the original basis.
 
|*Our demo uses stm32f103zet6. If the customer modifies other models in MDK, such as stm32f103rbt6, the ram space becomes smaller, and the stack size and heap size in the startup file need to be modified on the original basis.
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}}
 
}}
 
{{FAQ|Can't display Chinese on the e-ink screen?
 
{{FAQ|Can't display Chinese on the e-ink screen?
|The Chinese character library of our routine uses GB2312 encoding method, please change your xxx_test.c file to GB2312 encoding format, compile and download it, and it will display normally
+
|The Chinese character library of our demos uses GB2312 encoding method, please change your xxx_test.c file to GB2312 encoding format, compile and download it, and it will display normally
 
}}
 
}}
 
{{FAQ|The e-Paper display is too dark or too light?
 
{{FAQ|The e-Paper display is too dark or too light?
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}}
 
}}
 
{{FAQ|When testing the program, the program has been stuck in e-Paper busy?
 
{{FAQ|When testing the program, the program has been stuck in e-Paper busy?
|*It may be caused by the unsuccessful spi driver<br/>
+
|*It may be caused by the unsuccessful spi driver.<br/>
1. First check whether the wiring is correct<br/>
+
1. First check whether the wiring is correct.<br/>
2. Check whether the spi is turned on and whether the parameters are configured correctly (spi baud rate, spi mode and other parameters)<br/>
+
2. Check whether the spi is turned on and whether the parameters are configured correctly (spi baud rate, spi mode and other parameters).<br/>
 
}}
 
}}
 
+
</div></div>
 +
<div class="toccolours mw-collapsible mw-collapsed">
 
==Question about Hardware==
 
==Question about Hardware==
 +
<div class="mw-collapsible-content">
 
{{FAQ|Can Arduino 3.3V drive the ink screen?
 
{{FAQ|Can Arduino 3.3V drive the ink screen?
|Yes, now there is a level conversion chip onboard, supporting 3.3V drive
+
|Yes, now there is a level conversion chip onboard, supporting 3.3V drive.
 
}}
 
}}
 
{{FAQ|What should be paid attention to when designing the driver board?
 
{{FAQ|What should be paid attention to when designing the driver board?
Line 39: Line 43:
 
}}
 
}}
 
{{FAQ|Can I use analog SPI?
 
{{FAQ|Can I use analog SPI?
|Yes, pay attention to the correct timing<br/>
+
|Yes, pay attention to the correct timing.<br/>
 
}}
 
}}
 
{{FAQ|Why is the BUSY pin always busy?
 
{{FAQ|Why is the BUSY pin always busy?
|Check if SPI communication is normal<br/>
+
|Check if SPI communication is normal.<br/>
Confirm whether the BUSY pin is normally initialized to input mode<br/>
+
Confirm whether the BUSY pin is normally initialized to input mode.<br/>
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)
+
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<br/>
+
If the busy function sends the 0x71 command, you can try to comment it out.<br/>
 
}}
 
}}
 +
</div></div>
 +
<div class="toccolours mw-collapsible mw-collapsed">
 
==Question about Screen==
 
==Question about Screen==
 +
<div class="mw-collapsible-content">
 
{{FAQ|What is the usage environment of the e-ink screen?
 
{{FAQ|What is the usage environment of the e-ink screen?
|*【Working conditions】Temperature range: 0~50°C; Humidity range: 35%~65%RH<br/>
+
|*【Working conditions】Temperature range: 0~50°C; Humidity range: 35%~65%RH.<br/>
*【Storage conditions】: Temperature range: below 30°C; Humidity range: below 55%RH; Maximum storage time: 6 months<br/>
+
*【Storage conditions】: Temperature range: below 30°C; Humidity range: below 55%RH; Maximum storage time: 6 months.<br/>
*【Transportation conditions】: Temperature range: -25~70°C; Maximum transportation time: 10 days<br/>
+
*【Transportation conditions】: Temperature range: -25~70°C; Maximum transportation time: 10 days.<br/>
*【After unpacking】: Temperature range: 20°C±5°C; Humidity range: 50±5%RH; Maximum storage time: Assemble within 72 hours<br/>
+
*【After unpacking】: Temperature range: 20°C±5°C; Humidity range: 50±5%RH; Maximum storage time: Assemble within 72 hours.<br/>
 
}}
 
}}
 
{{FAQ|Precautions for e-ink screen refresh
 
{{FAQ|Precautions for e-ink screen refresh
 
|*refresh mode<br/>
 
|*refresh mode<br/>
**Full brush: 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<br/>
+
**Full brush: 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.<br/>
**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)<br/>
+
**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).<br/>
 
**refresh rate<br/>
 
**refresh rate<br/>
**During use, it is recommended that customers set the refresh interval of the e-ink screen to at least 180 seconds (except products that support the local brush function)<br/>
+
**During use, it is recommended that customers set the refresh interval of the e-ink screen to at least 180 seconds (except products that support the local brush function).<br/>
 
**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 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)<br/>
+
**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).<br/>
 
*Application<br/>
 
*Application<br/>
**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 determine whether the use environment meets the requirements of e-ink screen<br/>
+
**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 e-ink screen.<br/>
 
}}
 
}}
 
{{FAQ|What is the refresh rate/lifetime of the e-ink screen?
 
{{FAQ|What is the refresh rate/lifetime of the e-ink screen?
|Ideally, with normal use, it can be refreshed 1,000,000 times (1 million times)
+
|Ideally, with normal use, it can be refreshed 1,000,000 times (1 million times).
 
}}
 
}}
 
{{FAQ|After using for a period of time, the screen refresh (full refresh) has a serious afterimage problem that cannot be repaired?
 
{{FAQ|After using for a period of time, the screen refresh (full refresh) has a serious afterimage problem that cannot be repaired?
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}}
 
}}
 
{{FAQ|Why is the image displayed offset
 
{{FAQ|Why is the image displayed offset
|Maybe the SPI rate is too high, resulting in data loss, try to reduce the SPI rate<br/>
+
|Maybe the SPI rate is too high, resulting in data loss, try to reduce the SPI rate.<br/>
Insufficient or unstable power supply leads to data loss<br/>
+
Insufficient or unstable power supply leads to data loss.<br/>
The data cable is too long to cause data loss, the extension cable should not exceed 20cm<br/>
+
The data cable is too long to cause data loss, the extension cable should not exceed 20cm.<br/>
 
}}
 
}}
 
{{FAQ|What is the waveform file of the e-ink screen and what does it do?
 
{{FAQ|What is the waveform file of the e-ink screen and what does it do?
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}}
 
}}
 
{{FAQ|What is the process of brushing e-paper?
 
{{FAQ|What is the process of brushing e-paper?
|There are mainly two types of ink screens<br/>
+
|There are mainly two types of ink screens.<br/>
One is to brush the background image first<br/>
+
One is to brush the background image first.<br/>
The other is to alternately refresh old data and new data<br/>
+
The other is to alternately refresh old data and new data.<br/>
 
}}
 
}}
 
{{FAQ|How do I play in different positions at the same time?
 
{{FAQ|How do I play in different positions at the same time?
|Simultaneous brushing in different locations needs to be operated in the program design, that is, first brushing the data of different locations into the electronic paper IC, and finally doing the Updata/TurnOnDisplay uniformly.
+
|Simultaneous brushing in different locations needs to be operated in the program design, that is, first brushing the data of different locations into the electronic paper IC, and finally doing the Update/TurnOnDisplay uniformly.
 
}}
 
}}
 
{{FAQ| Does the three-color e-Paper have a red/yellow color difference?
 
{{FAQ| Does the three-color e-Paper have a red/yellow color difference?
|Yes, when e-Paper is batched, there will be some color difference, which is a normal phenomenon. Store the e-paper face up to reduce the reddish/yellowishness to a certain extent.
+
|Yes, when e-Paper is batched, there will be some color difference, which is a normal phenomenon. Store the e-paper faces up to reduce the reddish/yellowishness to a certain extent.
 
}}
 
}}
 
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</div></div>
 +
<div class="toccolours mw-collapsible mw-collapsed">
 
==Others==
 
==Others==
{{FAQ| Are bare screen shipped with a film?
+
<div class="mw-collapsible-content">
|with film
+
{{FAQ| Are bare screens shipped with a film?
 +
|with film.
 
}}
 
}}
 
{{FAQ| What is the specification of the screen cable interface?
 
{{FAQ| What is the specification of the screen cable interface?
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}}
 
}}
 
{{FAQ| What type of connector does the ink screen use?
 
{{FAQ| What type of connector does the ink screen use?
|Cable socket 0.5-24pin rear flip type 2.0H (FPC connector)
+
|Cable socket 0.5-24pin rear flip type 2.0H (FPC connector).
 
}}
 
}}
 
{{FAQ| Does e-Paper have a built-in temperature sensor?
 
{{FAQ| Does e-Paper have a built-in temperature sensor?
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}}
 
}}
 
{{FAQ|Why can't the image be displayed after full brushing?
 
{{FAQ|Why can't the image be displayed after full brushing?
|The full brush initialization function needs to be added when the ink screen is switched from partial brush to full brush
+
|The full brush initialization function needs to be added when the ink screen is switched from partial brush to full brush.
 
}}
 
}}
 
{{FAQ| Why is the printing information normal when running the python program but the ink screen does not respond?
 
{{FAQ| Why is the printing information normal when running the python program but the ink screen does not respond?
|It may be a demo based on the BCM2835 library that has run the C language before. At this time, you need to restart the Raspberry Pi and then run the python demo
+
|It may be a demo based on the BCM2835 library that has run the C language before. At this time, you need to restart the Raspberry Pi and then run the python demo.
 
}}
 
}}
 +
</div></div>

Latest revision as of 07:57, 30 September 2022

Question about Software

 Answer:
*Our demo uses stm32f103zet6. If the customer modifies other models in MDK, such as stm32f103rbt6, the ram space becomes smaller, and the stack size and heap size in the startup file need to be modified on the original basis.
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
*Install the imaging library using the command sudo apt-get install python-imaging
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
If it is a three-color screen, when you need to transmit B/W data, use Data Start Transmission 1, when transmitting RED data, use Data Start Transmission 2, because the 2.13inch e-Paper HAT (D) can only display black and white, Therefore, when working in KW mode Data Start Transmission 1, the last data is sent, that is, the so-called old, and 0x00 is directly sent in the program. When Data Start Transmission 2, the data that needs to be refreshed, the so-called "NEW" is sent. data.
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
The Chinese character library of our demos uses GB2312 encoding method, please change your xxx_test.c file to GB2312 encoding format, compile and download it, and it will display normally
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
You can adjust the value of Vcom in the program to change the display contrast, and the screen improvement effect with local brushing is particularly obvious.
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
The border display color can be set through the Border Waveform Control register or the VCOM AND DATA INTERVAL SETTING register.
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
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).
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
The process of re-awakening the e-ink screen is actually the process of re-powering on the power. Therefore, when the EPD wakes up, it must first clear the screen, so as to avoid the afterimage phenomenon to the greatest extent.
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
*It may be caused by the unsuccessful spi driver.

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).

{{{3}}}
{{{4}}}

{{{5}}}


Question about Hardware

 Answer:
Yes, now there is a level conversion chip onboard, supporting 3.3V drive.
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
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 ink screen.

Device selection can use the model in the schematic diagram we provide or choose according to the data sheet.

{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
Yes, pay attention to the correct timing.
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
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.

{{{3}}}
{{{4}}}

{{{5}}}


Question about Screen

 Answer:
*【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.
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
*refresh mode
    • Full brush: 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 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).
  • 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 e-ink screen.
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
Ideally, with normal use, it can be refreshed 1,000,000 times (1 million times).
{{{3}}}
{{{4}}}

{{{5}}}


 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.
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
Yes, but you need to re-initialize the electronic paper with software.
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
Maybe the SPI rate is too high, resulting in data loss, try to reduce the SPI rate.

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.

{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
The display gray scale of electrophoretic electronic paper is determined by the spatial position of the particles in the microcapsule or microcup. The electrophoresis phenomenon occurs between black particles and white particles under the action of voltage. This voltage sequence that promotes the electrophoretic movement of the particles is the driving force of the electronic paper. waveform. The driving waveform is the core part of the electronic paper display, and the optimization of the driving waveform will directly affect the display effect of the display. The driving waveform file is used to describe the parameters formed by the voltage sequence that promotes the electrophoretic movement of the particles, and it needs to be called regularly when the electronic paper is refreshed.

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 The manufacturer of 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.

{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
LUT is the abbreviation of LOOK UP TABLE, and OTP is the abbreviation of ONE TIME PROGRAM. The original intention of LUT is to load waveform files, and the waveform files are divided into OTP and REGISTER. Among them, OTP is the built-in waveform storage method, and REGISTER is the external waveform storage method.
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
There are mainly two types of ink screens.

One is to brush the background image first.
The other is to alternately refresh old data and new data.

{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
Simultaneous brushing in different locations needs to be operated in the program design, that is, first brushing the data of different locations into the electronic paper IC, and finally doing the Update/TurnOnDisplay uniformly.
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
Yes, when e-Paper is batched, there will be some color difference, which is a normal phenomenon. Store the e-paper faces up to reduce the reddish/yellowishness to a certain extent.
{{{3}}}
{{{4}}}

{{{5}}}


Others

 Answer:
with film.
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
0.5mm pitch, 24Pin.
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
Cable socket 0.5-24pin rear flip type 2.0H (FPC connector).
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
At present, all screens have built-in temperature sensors, and external LM75 temperature sensors can also be used with IIC pins.
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
The full brush initialization function needs to be added when the ink screen is switched from partial brush to full brush.
{{{3}}}
{{{4}}}

{{{5}}}


 Answer:
It may be a demo based on the BCM2835 library that has run the C language before. At this time, you need to restart the Raspberry Pi and then run the python demo.
{{{3}}}
{{{4}}}

{{{5}}}