Notice, pre-orders will start before December 10th.

20201129 update

1. Replace the ESP32 module. The 4MB FALSH module is not enough and the price is not cheap. Use the 8MB FLASH and no longer have to worry about the font problem. 2. Change the power supply to HT7333. Although the current is smaller, it is still sufficient. A luxurious tantalum capacitor is added to prevent accidents. 3. Replace the upper and lower screws with M2.5 screws and place them on the left and right sides to increase the space for the inner battery. 4. The buttons are changed from 6*6 with brackets to 4.5*4.5 without brackets, and the height is lowered. 5. Reset and IO0 are replaced with SMD buttons with pillars, which can be pressed without the need for button caps. 6. Some minor modifications to adapt to the acrylic box.

Acrylic table

basic skills

• Time display, refreshed every minute
• weather forecast display
• Custom message function, you can display news directly or send custom messages through the server
• The memo shows that it is related to Microsoft todu
• Display date, lunar calendar and other information
• Indoor temperature and humidity display
• Power display
• Supports unicode full characters and Chinese display, supports multiple fonts
• 16-level grayscale display

Hardware parts

powered by

The module power supply requires -32V, +25V, +15V, -15V and 5-9V power supply for VCOM. The original screen manufacturer recommends using MAX17135 or TPS65185 for power supply, but these two ICs have complex peripheral circuits and are in QFN packages, making them inconvenient for soldering. Replaced with LT's LT1945. LT1945 outputs two high-voltage power supplies, positive and negative, and achieves ±15V through two Zener diodes. And realize adjustable VCOM power supply through adjustable resistor and op amp.

clock

The screen requires 16M or 32M clock input. After testing, using ESP32 to output a 40Mhz square wave signal can also work stably. Therefore, the hardware uses the 40Mhz PWM provided by ESP32 as the clock. Other MCUs can be adjusted according to actual conditions.

Arduino environment setup

Install ARDUINO

Install esp32 API

Install dependent libraries

l Arduino-sht 1.1.0 l ArduinoJson 6.16.1 l I2C BM8563 RTC

SPIFFS toolkit

FLASH configuration

For the ESP32 DEV module FLASH size 8MB Partition selected for the ESP32 development board, select the Default 4MB with 1.5SPIFFS option. The system does not have SPFFI allocated under 8M, so you need to change the CSV file of the partition in the system directory. The directory is as follows (the installation version of Arduino is selected according to your own computer). C:UsersThinkPadAppDataLocalArduino15packagesesp32hardwareesp321.0.4 oolspartitions default_8MB.csv changed to nvs, data, nvs, 0x9000, 0x5000, otadata, data, ota, 0xe000, 0x2000, app0, app, ota_0, 0x10000, 0 x140000, app1, app, ota_1, 0x150000,0x140000 , spiffs, data, spiffs, 0x290000, 0x570000, allocate more than 5M space to spiffs, and put all the fonts and initialization files into spiffs. Reduce compile time burden.

4-inch ink screen

ESP32,arduino programming