ESP-IDF: General Purpose Input Output ESP32 (Buzzer)

Two weeks ago, i discovered about ESP-IDF, the official framework for ESP32 and ESP8266 Microcontroller development.

Developing for the ESP32 with ESP-IDF offers many features:

Support for FreeRTOS
Writing program in the C language
More low level of control, memory management, and hardware options

Write a Code in ESP-IDF

The workflow between Arduino and ESP-IDF is different, but you dont have to worry because i dont think it will be a big problem.

There are no void setup() and void loop() functions in ESP-IDF. Instead, you do everything in the void app_main() function.

Also, primary language ESP-IDF is C language, not plus-plus in the end.

Some people write ‘Arduino-IDE uses C/C’ which makes others believe C and C++ are the same. In fact, they are not. I wont explain it in here, but you can read about in these article.

Simple Passive Buzzer with ESP-IDF

The first time I tried writing a program with ESP-IDF, i was shocked by the length of code required for a simple program when compared to writing it with the Arduino IDE.

So, let me show you how to use GPIO with ESP-IDF. In this context, we will create a simple bassive buzzer.

I hope you have finished installing ESP-IDF. If not, you should read “Get Started - ESP32 ESP-IDF”.

Create a project directory. I will name it as buzzer.

$ idf.py create-project buzzer

Change the directory to buzzer and start editing the file inside main/ with your favorite text editor.

$ cd buzzer
$ vim main/buzzer.c

We will add several libraries and i will explain each of them.

As the name suggests, we will use this for GPIO activity.

#include <driver/gpio.h>

With task.h, we will use the vTaskDelay() function which works like delay() in the Arduino IDE.

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"

Lastly, we use this library for logging activity when monitoring.

#include "esp_log.h"

The 2 stands for GPIO2. You can change it according your taste.

#define BUZZER_PIN 2

Now, we will write a code inside void app_main() function.

This function sets the direction of the GPIO to be used as an output.

gpio_set_direction(BUZZER_PIN, GPIO_MODE_OUTPUT);

Add while(1) to work like void loop(). Next, we will make the buzzer works inside the while loop.

while(1) {
/* writing code in here */
}

We will start by turning the assigned gpio with gpio_set_level function, which has two modes:

1 for active
0 for inactive

gpio_set_level(BUZZER_PIN, 1);

Add a one-second delay.

vTaskDelay(1000 / portTICK_PERIOD_MS);

Give a sign that the code is working.

ESP_LOGI("Buzzer", "Active");

Now, its your turn to imagine how buzzer will turn off :). Make sure to close all code with }.

Here is the full code:

#include <driver/gpio.h>
#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_log.h"

#define BUZZER_PIN 2
void app_main() {
    gpio_set_direction(BUZZER_PIN, GPIO_MODE_OUTPUT);
    while(1)
    {
        gpio_set_level(BUZZER_PIN, 1);
        
        vTaskDelay(1000 / portTICK_PERIOD_MS);
        ESP_LOGI("Buzzer", "Active");

        gpio_set_level(BUZZER_PIN, 0);
        vTaskDelay(1000 / portTICK_PERIOD_MS);
        ESP_LOGI("Buzzer", "Non-Active");
    }
}

After that, we will flash the code to the ESP32 device.

$ idf.py flash

And monitor the results

$ idf.py monitor