ESP32 projects

Used components:

1. HW components

   • ESP32-WROOM-32D target board
   • SSD1306 monochrome display
   • WS2813 RGB LED strip (16 LEDs)

2. SW components

   • Linux Mint 20.3 (kernel 5.4) development host
   • standard ESP-IDF Eclipse plug-in, link
   • external ESP-IDF-LIB library, link

Setup

1. Connection layout

ESP32-WROOM-32D	SSD1306	WS2813
3V3	VCC	n/c
GND	GND	GND
21	SDA	n/c
22	SCL	n/c
5V	n/c	5V
5	n/c	DI

note: n/c - not connected

Applications

1. Effects with the RGB LED strip ('led_effects' example from an external ESP-IDF-LIB library: link)

1.1. Project development in Eclipse

• Assume the locations of the external ESP-IDF-LIB library and its example application are in:

$HOME/esp/esp-idf-lib  # library
$HOME/esp/esp-idf-lib/examples/led_effects # example

• If the example project should be imported into the default Eclipse workspace, then use Eclipse menu commands:
  • 'File' -> 'Import...' -> 'Espressif' -> 'Existing IDF Project': click on 'Next'
    • On 'Import Existing Project' click on 'Browse...' to locate the existing project and click on 'Open'
    • Re-name the project in 'Project Name' and enable the 'Copy project into workspace' checkbox
  • Alternately, if the example project should be imported into other location (ie., 'eclipse-workspace/esp32'), use manual copy and then import it
    • Copy the example directory into your desired location (and re-name the directory)
    • Import it in Eclipse: nor copying in the workspace neigther re-naming of project is necessary
• Edit 'CMakeLists.txt' to specify the external ESP-IDF-LIB library, otherwise compilation will fail (cannot find the included header files)

set(EXTRA_COMPONENT_DIRS ${CMAKE_CURRENT_SOURCE_DIR}/../../../esp/esp-idf-lib/components)

• Now the project can be built properly with the external library

1.2. Run the application on the Wokwi online simulator

• Start the simulator on your web browser
• Start with the new project with the 'ESP32' board
• Load 'NeoPixel Ring' for WS2812 (yes, WS2812 and WS2813 are compatible)
• Make 2 connections:

ring1:GND - esp:GND.2
ring1:DIN - esp:D5

• On 'sketch.ino' tab press 'F1' button (or right click) to load the command palette
• Select 'Load HEX and start simulation' command
• Load your *.bin file:

led_effects/build/example-led_effects.bin # from the local project directory

• The simulation will run,
  • debug output will be seen on the simulator serial monitor window
  • LED ring will play the programmed effects

1.3. Run the app on the target board,

• idle current is 10,15 mA
• max current usage is 37,92 mA (default brightness=20)
• adjust the brightness in the SDK configuration:
  • 'Example configuration' -> 'brightness of LEDs'
  • with brightness=10, max current usage changes to 18,36 mA