ESP32 E-Reader Project

Opensource ESP-32 EPaper Display Device

Discalimer

Project comes with ABSOLUTELY NO WARRANTY. Author is not responsible for any damage made to individuals or their property while attempting to build or/and use the product.

Features

Hardware

Note

Schematic, gerber and 3mf files for building PCB and housing are availble under hardware folder of the repository.

• Popular and cheap ESP32 platform.
• Big 800x480 Good Display GDEQ0426T82 E-Paper SPI Diaplay.
• USB-C power, charing and firmware upload.
• Micro SD Card support (SPI Interface).
• Low power consumption: ~2mA in sleep mode.
• Optinal JTAG connector for debug purposes.
• External clock crystal for accurate time.
• Ability to control external hardware e.g., backlight.
• Power and battery level dtection.
• All components available on aliexpress almost for free.
• 30th/15th vias for lowering PCB manufaturing cost.

Warning

Currently the project is using external DESPI-C02 driver board for interfacing with EPD. This will potentially be changed in the further implementations as external driver board does not allow to make thin housing design.

Bill Of Materials

BOM CSV

Software

• PlatformIO, Arduino Framework.
• LVGL driver for GDEQ0426T82 display with partial refresh, 2 buffers and partial rendering support.
• MVC framework featuring abstract Intent and Widget concepts.

Pictures

Software Used

• Labcenter Proteus
• FreeCAD
• Platform IO
• Visual Studio Code

Special Thanks

• Andre' Lamothe for sharing his passion for electronics with so many people
• Ben Eater
• @MangoJellySolutions for a great FreeCAD course

Project Notes

No PSRAM Support

• Chip Used: ESP32-D0WD-V3
• Chip with PSRAM: ESP32-D0WDR2-V3 (R - has ram, 2 - size in megs)

Log Levels

build_flags =
    ; ESP Log level
    -D CORE_DEBUG_LEVEL=4

Supported 8 Bit BMPs

Set lv_conf.h parameter, in my case in platfromio.ini:

build_flags =
    -D LV_COLOR_DEPTH=8

Converting image with GIMP:

• Use Image -> Mode -> Indexed with 256 colours and dithering if needed.
• Export as a filename.bmp, the Advanced Options are greyed out.
• Depending on purpose you might need to toggle color space info on/off.

TODO List

Software

• Further adjust README.MD further

Hardware

• Implement diff pairs for USB
• Move battery, backlight Connectos, so they do not interfere with housing
• Integrate DESPI-C02 into PCB
• Position ESP-32 chip so the antenna is placed outside of the board

WIKI

• Display: 800x480
• pio test -vv will show serial moitor output
• pio test -vv -f "test_textIndex" filter tests based on a directory
• Battery Sense
• SD Card
• Interrupts
• Sleep