ESP32-8bit pixel screen: EmojiCube

#EmojiCube Project Introduction> DIY 8*8 pixel screen, ESP32 main control, programmable, customized display content, low cost, very simple, novice-friendly! > Project B: [https://www.bilibili.com/video/BV14L4y1t7EG](https://www.bilibili.com/video/BV14L4y1t7EG) > Project gitee warehouse: [https://gitee.com/lhcstation /emoji-cube](https://gitee.com/lhcstation/emoji-cube) > Last updated on 2022.3.11 > **Thank you for your likes. It has been two months since the project was released. I have received many suggestions and I am constantly improving this project, but unfortunately my time and energy are limited. In addition, I have also returned to school. There is no equipment for welding boards in the school dormitory, so some ideas cannot be realized for the time being. The PCB hardware of this project will no longer be updated, but the software part will remain updated. It is expected to go home this summer and create a new project, EmojiCube V2.0, to redesign the PCB hardware. Friends are welcome to leave valuable suggestions:>** ## Design The source of ideas and some materials come from the project: [IoT Emoji Sign](https://make.quwj.com/project/340) **In the simplest and low-cost way**, using the powerful IoT function of ESP32, Implement a sign displaying 8x8 pixel Emoji## Project completion progress* Update date: 2022.1.27 * [x] Schematic, PCB, 3D shell design* [x] Physical verification* [x] Interactive front-end web design* [ ] Custom drawing function* [ ] Brightness control* [ ] Touch button programming* [ ] Animation, time, weather display function## Update log### 2.26 update log* PCB update: Copper should not be laid under the ESP antenna (personal feeling It has no impact, the wifi signal of the previous copper-layed version is normal); the touch electrode of the ws2812 data touch chip is led out in the form of a pad, which is convenient for use; the previous version of the PCB can be used, and it is not mandatory to update this version, and the position of the components has not been changed. ![pcb.png] * Software update: It is recommended to update, fix the bug of garbled dot matrix in some cases, and add the brightness adjustment function. For better shading effect, it is recommended to blacken the shell or lower the brightness. Please check the gitee warehouse Update code. * The firmware has been compiled, please check it on the gitee warehouse release page, which includes this version of the firmware and Espressif's official Flash burning tool! [release] ### 3.4 update log * The shell has been updated to optimize the shading of the raster. Many other details have been verified! [11.jpg] ![22.jpg] ## The schematic design uses the following modules: download circuit CP2102; main control ESP32-WROOM-32D; TTP223 touch chip; pin connection instructions: GPIO4 < ------> Lamp bead DIN; GPIO2 <------> Touch chip TTP223: Q![pic4.png] ## The PCB design is as shown below, the lower right rectangular pad is the touch area, and the front is the light Beads, the reverse side is the main control esp part! [pic5.png] ## The 3D shell design is designed using Fusion360. The engineering attachment provides stl files. The shell size is about 60×60×15mm. It is recommended to use black material for printing or white material for printing and then put on. The groove on the black outer wall is used to place the touchpad, with three positions reserved. I personally tested it and the sensitivity is OK, but the most sensitive one is to just stick the touchpad on the back cover. I found it under the 3D Monkey created by Jiali. For single printing, the total cost for the upper and lower covers is about 12 yuan. For reference, the front and rear covers are fixed with 4 M2×5mm screws (diameter 2mm, thread length 5mm)! [out.png] ## Software & Interactive Front-end Design* Using ESP The Internet of Things function provides two interaction methods: AP soft routing/wifi distribution network; either way, it can be accessed in the browser through the MDNS service: [http://esp32.local/](http:// esp32.local/) Enter the main interface * ![pic6.png] * The browser and ESP interact through ajax; click on the emoticon to display the specified image * Considering that it is troublesome to log in to the browser every time to switch emoticons, so A touch switch is reserved as an **offline** interactive tool, that is, you can switch expressions by touching the switch (it is expected to design an expression collection list) * All files: html, json, etc. are stored in Flash SPIFFS file system * Custom images Display: Refer to pico-8 game design, using 16 colors, under development [Experience Connection](https://lhcstation.gitee.io/gen8bit-pic) ![pic9.png] ## Cost Analysis & Reproduction Suggestions * Completely welded by yourself: esp main control is about 12; cp2102 is about 11; 100 lamp beads are 30; other resistors and capacitors are about 10, 3D shell is about 10, a total of less than 80 * Welding is not difficult, the pcb board is designed for volume Smaller, you can also buy a development board that has been soldered, which greatly reduces the soldering work and is cheaper* There is an 8*8 pixel screen sold on tb, which is quite cheap. The size of this lamp bead is 5×5mm , the overall size is about 60×60mm. For the smaller size, I use **3.5mm** lamp beads, as shown on the right, 100 pieces are sold for 30 with free shipping, and they are not soldered for you, so it is a bit expensive orz. * By the way, I would like to remind you to make sure the arrangement of the lamp beads on the screen is **Z-shaped or snake-shaped** when purchasing. My PCB design is **Snake-shaped** *! [pic7.png] * I bought the main control The ESP32 module Flash size is 16MB and costs 19 yuan each. In fact, buying a 4MB module is enough for about 11 yuan each* You can directly buy a soldered development board, which is not expensive and is very convenient without having to solder it yourself* USB conversion The serial port chip is CP2102 which costs 11 yuan each. It will be very cheap to use ch340 chip* ![pic8.png] ## Engineering attachments* stl shell file* PCB files please directly use Lichuang eda to open and edit online* Due to frequent software updates, Please obtain it from the gitee warehouse, which provides compiled firmware (.bin) + source code (arduinoIDE) + source code (platformIO)