DIY 3.7-inch ink screen e-reader clock ESP32

Homemade esp32 ink screen novel reading solution
1124 Fix the firmware not updating the date in time the next day.
Modify the capacitors of the PCB ink screen driver. No effect on the board. Pay attention when welding. The schematic diagram has been modified. The pcb welding reference diagram has been modified. Add new firmware. Full refresh every 20 pages. It may prevent overdriving.
Advantages:
1. Pure enjoyment version of e-book, no other functions, just enjoy the fun of reading, portable, ultra-narrow border, easy to carry with clock interface, one-click clock switch
2. You can modify the font size, character spacing, line spacing, display direction, etc., display the current time and progress, power when reading
3. Low power consumption, except for waking up when refreshing, it is in sleep all the time, including when you are reading novels, the prototype test power consumption is 10+ua, super long battery life, ridiculously long
Disadvantages:
1. Only supports txt novels in utf-8 encoding format, does not support other formats such as epub and other encodings
2. Single function, only e-book function and clock function
3. Occasionally there will be unexpected "features", but it hardly affects daily use
 
Provide hardware schematics and pcb and garber files for printing pcb, 3d printing stl and source files, all of which can be modified by yourself, provide bom and free firmware
 
PCB printing precautions
1. PCB printing thickness 1.2mm.
2. There are two versions of pcb. The first version is the same as my picture. The button design is not very reasonable and easy to press by mistake, but it's okay. The other version adjusts the button position so that it is not easy to press by mistake. This is the difference between the two versions
3. There are only component numbers on the PCB, and the attachment provides a reference diagram for PCB component welding. Basically, just follow the layout.
 
BOM-related precautions
1. The button uses Kaihua 9.5mm silent micro switch extended button version with a size of 6*6*9.5 , the welding type needs to use tweezers to adjust the two metal contacts and bend them to the corresponding pcb position.
2. The e-ink screen uses a 3.7-inch black and white e-ink screen with a long curved cable. The schematic diagram is provided below (I bought the black and white version on Taobao for 55 yuan). The UC8253 with the same cable resolution of 240*416 can be used.
3. The e-ink screen supports UC8253 with a resolution of 240*416 in three colors and black and white by default, but the pcb provided only supports the long and curved cable version, which can be modified by yourself.
4. The original number of some capacitors and resistors in the BOM is wrong. You can use the same specification 0603. The error is arbitrary. The recommended voltage resistance of 1uf is above 25v, and the rest of the voltage resistance is above 5v. Basically, it is arbitrary
. 5.ES The P32 version is the wroom-32 version 8M or 16M. It is recommended to use 16M directly. The price difference is about two yuan.
6. The schematic diagram shows BL8025T. I actually use RX8025T, which should be universal. The latter is recommended.
7. The maximum thickness of the lithium battery is 4mm, the maximum length is 8cm, and the maximum width is about 4.4cm. It is recommended to use 4cm. The corresponding interface adapter cable is required or the positive and negative electrodes are directly welded to the corresponding solder joints on the PCB.
8. For many materials, you can refer to the open source versions of half sugar or glycyrrhizic acid, which are roughly similar. If you have any questions, you can refer to the instructions of other open source projects.
Firmware related precautions
1. The firmware needs to be burned with a data cable. Refer to the instructions of other open source projects, or Baidu esp32 The method of burning the firmware is not provided here, and please don't ask such questions.
2. The firmware is basically ok after trial use. Occasionally, some features will not affect the use. If there is no accident, the new version will not be updated .
 
Operation instructions:
1. First, press the EN button at any time and in any interface to return to the clock interface
. 2. Press the combination key EN+Button 1 at any time (the method is to hold down button 1, then short press the EN button, and then release button 1 for 1-2 seconds), the function is the main menu interface.
3. Press the combination key EN+Button 2 at any time to directly return to the last reading progress (Note!!! You must have read any few pages of a novel before)
4. The menu interface is button 1 to switch to button 2 selection.
5. The first time you need to select Calibration on the main menu interface to calibrate the time. Follow the prompts on the screen when calibrating.
6. The novel must be placed in the novel directory under the root directory of the SD card (that is, the directory under the sd card such as /novel/my novel.txt), and supports up to 5 novels. Unpredictable errors may occur if there are more than 5 novels! And the novel is encoded in utf-8. If not, just change the encoding when saving as in Notepad.
7. While reading the novel, short press button 1 for the next page, short press button 2 for the previous page, and long press button 1 for the option menu, where you can modify various settings and jump progress.
8. The reset option under the main menu directory should be basically useless. In case of an inexplicable error, you can try to restore the default value.
 
Notes when installing the ink screen and PCB to the 3D printed shell
1. Please be sure to refer to the schematic diagram for installation precautions. The first version did not take into account the pcb wiring, so it must be installed in this way to be stuck.
2. The 3D printed stl error is extremely small, just right, not too big or too small, and it can generally be installed. If it cannot be installed, it may be due to the error of your printer or poor local printing effect. You can enlarge it and print it a little bit, or modify the 3D source file yourself. Provide the old version of 3D printing file cr6-SE printer suitable for slicing files, the old version of the upper and lower spacing has 0.6MM, the new version has only 0.2mm
3.3D printing support is recommended to be added according to the picture below, otherwise it is not easy to remove the support. Ignore the online printing
4.3D printed body and cover fixing method is 502, it is recommended to test it first and then fix it, use a toothpick to dip a little 502 and click a few times to fix it, and use a utility knife to cut it when removing it.
 
Finally, if there is any supplement, it may be added directly in the comment.
The capacitor modification of the PCB ink screen driver part has been modified, the schematic diagram has been modified, the pcb welding reference diagram has been modified, and the new firmware has been added. Full refresh every 20 pages may prevent overdriving