ESP32 REST BUTTON

A physiacl button to the ESP32 will send out a REST request to a given server.

• ESP32 REST BUTTON
  • TODOs
• Setup
  • Drivers
• Development and Flashing
  • VS-Code with Espressif
• Run
  • Setting up WIFI
  • Powering via Battery
• Further Reading

TODOs

• DMX Web Endpoint configurable into nvs via webserver
• DMX Web Reqeust Configurable content

Setup

Drivers

To support UART flashing and debugging:

1. Download the CP210x VCP driver for your OS
2. Unpack, if necessary
3. Follow the steps for your Operating System to install the drivers.

Development and Flashing

The code must be compiled and flashed onto the ESP32 microcontroller via USB.

Prerequisites:

1. Have the necessary drivers installed as described above
2. Make sure your USB to micro-USB cable can transport data and not only charge!
3. Visual Studio Code with the espressif extension to support the build for the ESP with all required libraries.

VS-Code with Espressif

1. Open this repository in its own VS-Code instance.
2. Install the Espressif Extension - i used the extension version 1.6.3
3. Follow the extension setup process
   1. Select an ESP-IDF version (i used 5.0.2)
      • Note: This version differs from the extension versions, as it is two different things.
   2. Select an installation directory (i chose the workspace directory)
4. After the installation, restart VS-Code, just to be sure.
5. Make sure you followed the instructions for installing the driver
6. Select your ESP32 device by:
   1. Selecting UART as protocol (the star symbol at the bottom in VS Code)
   2. Selecting the right USB COM interface.

Here is an example settings.json for VSCode which can be put in the folder .vscode.. I especially recommend the setting for files.readonlyInclude to prevent editing ESP32 library files by accident and terminal.integrated.scrollback as an ESP restart quickly floods the default terminal size.

{
  "idf.flashType": "UART",
  "idf.adapterTargetName": "esp32",
  "idf.openOcdConfigs": [
    "board/esp32-bridge.cfg"
  ],
  "terminal.integrated.scrollback": 10000,
  "files.readonlyInclude": {
    "build/**": true,
    "**/esp/esp-idf/**": true,
    "**/.espressif/**": true
  }
}

You can then run ESP-IDF commands from VS-Code (CTRL+SHIFT+P)

• ESP-IDF: Build your Project
• ESP-IDF: Flash your Project
• ESP-IDF: Erase flash memory from device

or select them from the bottom tray menu.

Run

1. Build your project (CTRL+SHIFT+P -> ESP-IDF: Build your project)
2. Flash the Code onto the ESP32 (CTRL+SHIFT+P -> ESP-IDF: Flash your Project)
3. Turn on the power

Setting up WIFI

1. If no previously configured wifi can be reached, the esp32 opens its own wifi with SSID ESP32-REST-BTN and no password.
2. Connect to this wifi with a device and visit the default gateway (http://192.168.4.1) with your favorite browser.
3. On the webpage insert the credentials of the network you want to provision.

Powering via Battery

This seems to be a bit tricky, because the ESP32 seems to require a lot of energy when booting up WITH the wifi module active. Many batteries, that usually supply enough energy, cannot handle this burst in energy drain.

A list of setups, that worked for me:

• Lithium Battery CR123 (3.0V), connected to 3V3 PIN and GND

Further Reading

• More Documentation
• Help with Espressif