Experimental demo using ESP32-wrover kit and Rust

The main goal of the demo is to display line directions and departure times of public transport vehicles in Brno.

What the project does:

• Establish WiFi connection
• Configure ILI9341 display, HTTP Client and SNTP Client
• parse data from website (web scraping)
• init RTC and display current time with parsed data

Hardware setup

HW: Wrover-kit

https://docs.espressif.com/projects/esp-idf/en/latest/esp32/hw-reference/esp32/get-started-wrover-kit.html

Used pins

ILI9341	Wrover-kit
RST	GPIO18
CLK	GPIO19
D_C	GPIO21
CS	GPIO22
MOSI	GPIO23
MISO	GPIO25

HW: ESP32 with ILI9341 display

Wokwi

Used pins

ILI9341	ESP32-DevKitS-V1.1	Cable color
GND	GND	black
3.3V	3.3V	red
RST	GPIO4	green
CLK	GPIO18	orange
D_C	GPIO2	purple
CS	GPIO15	blue
MOSI	GPIO23	yellow
MISO	GPIO25	cyan

diagram.json

{
  "version": 1,
  "author": "Juraj Sadel",
  "editor": "wokwi",
  "parts": [
    {
      "type": "wokwi-esp32-devkit-v1",
      "id": "esp",
      "top": 0,
      "left": 0.67,
      "attrs": { "builder": "esp32-rust" }
    },
    { "type": "wokwi-ili9341", "id": "lcd1", "top": -354.05, "left": 182.84, "attrs": {} }
  ],
  "connections": [
    [ "esp:TX0", "$serialMonitor:RX", "", [] ],
    [ "esp:RX0", "$serialMonitor:TX", "", [] ],
    [ "esp:D4", "lcd1:RST", "green", [ "h0" ] ],
    [ "esp:3V3", "lcd1:VCC", "red", [ "v-1.02", "h132.77" ] ],
    [ "esp:GND.1", "lcd1:GND", "black", [ "h141.9", "v-1.79" ] ],
    [ "esp:D15", "lcd1:CS", "blue", [ "h0" ] ],
    [ "esp:D2", "lcd1:D/C", "purple", [ "h0" ] ],
    [ "esp:D18", "lcd1:SCK", "orange", [ "h0" ] ],
    [ "esp:D25", "lcd1:MISO", "cyan", [ "h-26.13", "v-106.89", "h328.67" ] ],
    [ "lcd1:MOSI", "esp:D23", "yellow", [ "v0" ] ],
    [ "lcd1:LED", "esp:3V3", "pink", [ "v226.59", "h-190.8" ] ]
  ],
  "serialMonitor": { "display": "terminal" }
}

Wokwi project link

https://wokwi.com/projects/332616143815574099

Devcontainers

The repository supports:

• Gitpod:
• Vs Code Devcontainers
• GitHub Codespaces

Build

• Terminal approach:

  ./build.sh  [debug | release]
  

  If no argument is passed, release will be used as default

• UI approach:

  The default build task is already set to build the project, and it can be used in VsCode and Gitpod:

  • From the Command Palette (Ctrl-Shift-P or Cmd-Shift-P) run the Tasks: Run Build Task command.
  • Terminal-> Run Build Task in the menu.
  • With Ctrl-Shift-B or Cmd-Shift-B.
  • From the Command Palette (Ctrl-Shift-P or Cmd-Shift-P) run the Tasks: Run Task command and select Build.
  • From UI: Press Build on the left side of the Status Bar.

Flash

Note When using GitHub Codespaces, we need to make the ports public, see instructions.

• Terminal approach:

  • Using custom runner in .cargo/config.toml:

    cargo +esp run [--release]
    

  • Using flash.sh script:

    ./flash.sh [debug | release]
    

    If no argument is passed, release will be used as default

• UI approach:
  • From the Command Palette (Ctrl-Shift-P or Cmd-Shift-P) run the Tasks: Run Task command and select Build & Flash.
  • From UI: Press Build & Flash on the left side of the Status Bar.

Wokwi Simulation

• Terminal approach:

  ./run-wokwi.sh [debug | release]
  

  If no argument is passed, release will be used as default

• UI approach:

  The default test task is already set to build the project, and it can be used in VsCode and Gitpod:

  • From the Command Palette (Ctrl-Shift-P or Cmd-Shift-P) run the Tasks: Run Test Task command
  • With Ctrl-Shift-, or Cmd-Shift-,

    Note: This Shortcut is not available in Gitpod by default.

  • From the Command Palette (Ctrl-Shift-P or Cmd-Shift-P) run the Tasks: Run Task command and select Build & Run Wokwi.
  • From UI: Press Build & Run Wokwi on the left side of the Status Bar.

Debuging with Wokwi

Wokwi offers debugging with GDB.

• Terminal approach:

  $HOME/.espressif/tools/xtensa-esp32-elf/esp-2021r2-patch3-8.4.0/xtensa-esp32-elf/bin/xtensa-esp32-elf-gdb target/xtensa-esp32-espidf/release/brno-public-transport -ex "target remote localhost:9333"
  

  Wokwi Blog: List of common GDB commands for debugging.

• UI approach: Debug using with VsCode or Gitpod is also possible:
  1. Run the Wokwi Simulation in debug profile

     Note that the simulation will pause if the browser tab is on the background

  2. Go to Run and Debug section of the IDE (Ctrl-Shift-D or Cmd-Shift-D)
  3. Start Debugging (F5)
  4. Choose the proper user:
     • esp when using VsCode or GitHub Codespaces
     • gitpod when using Gitpod