An ESP-IDF component for Physical Computing

Purpose

Generic Button functionality for ESP32 systems.

How it is done

For every button you want to use, you have to

• create an instance of class GenericButton

For every button event you want to detect, you have to

• prepare a callback function to handle the event
• register the event and the callback function for the button

When one of the registered events occurs, the corresponding callback function is triggered.

Where to find it

generic_button is published on the ESP Registry at https://components.espressif.com/components/elrebo-de/generic_button.

The source code can be found at https://github.com/elrebo-de/generic_button.

How to use it

As an ESP-IDF component generic_button must be included into idf_component.yml as a dependency. As usual this can be done by executing this command:

idf.py add-dependency "elrebo-de/generic_button^1.0.5"

In CMakeLists.txt "elrebo-de__generic_button" has to be added as a requirement.

Now you can include generic_button.hpp and use the GenericButton class in your program.

There are five parameters in the constructor of class GenericButton:

• tag – the tag used for logging from this instance of GenericButton class
• buttonPin – the GPIO pin number of the button
• activeLevel – the pin level when the button is active
• disablePull – set to true, when pullup/pulldown has to be disabled
• buttonType – one of “GPIO”, “ADC” or “MATRIX” (currently only “GPIO” is implemented)

Here the onBoard button of a ESP32-C6-DevKitM-1 V1.0 board is defined:

GenericButton onBoardButton(
    std::string("onBoardButton"),
    (gpio_num_t) 9, // GPIO
    0, // active = DOWN
    false, // pull enabled
    std::string("GPIO")
);

For every event you want to detect, you have to define a callback function. This function is called, when the event occurs.

Here is an example for the BUTTON_SINGLE_CLICK event:

// Callback function for BUTTON_SINGLE_CLICK event from onBoardButton
extern "C" void callback_onBoardButton_BUTTON_SINGLE_CLICK(void *arg, void *data)
{
    ESP_LOGI("onBoardButton Callback", "for Event BUTTON_SINGLE_CLICK called!");

    iot_button_print_event((button_handle_t)arg);

    // ToDo: add code here to execute in case of a single click
}

To register this callback function with your button you have to call RegisterCallbackForEventwith your GenericButton instance (here onBoardButton):

onBoardButton.RegisterCallbackForEvent(BUTTON_SINGLE_CLICK, callback_onBoardButton_BUTTON_SINGLE_CLICK);