View raw code<\/a><\/p>\n\n\n\nHow the Code Works<\/h3>\n\n\n\n In this section, we’ll take a look at the code to see how it works.<\/p>\n\n\n\n
Libraries<\/strong><\/p>\n\n\n\nWe start by including the required libraries:<\/p>\n\n\n\n
\nstdio.h<\/span> – the standard C library will be used for the printf<\/span> function that prints the debugging information in the serial monitor;<\/li>\n\n\n\nFreeRTOS.h<\/span> – provides the core FreeRTOS types and functions;<\/li>\n\n\n\ntask.h<\/span> – allows to use of the non-blocking delay function vTaskDelay<\/span>;<\/li>\n\n\n\ndriver\/gpio.h<\/span> – includes the functions required to configure and control GPIOs;<\/li>\n\n\n\nsdkconfig.h<\/span> – includes the project’s configuration file.<\/li>\n<\/ul>\n\n\n\n#include <stdio.h>\n#include <freertos\/FreeRTOS.h>\n#include <freertos\/task.h>\n#include <driver\/gpio.h>\n#include \"sdkconfig.h\"<\/code><\/pre>\n\n\n\nPin Assignment<\/strong><\/p>\n\n\n\nThis line assigns the on-board LED to GPIO 2<\/span>; you can change it to a different number to match your board pinout or to control a different GPIO.<\/p>\n\n\n\n#define LED_PIN 2<\/code><\/pre>\n\n\n\napp_main(void)<\/strong><\/p>\n\n\n\nWhen creating an ESP-IDF project, this function will always be called to run. This function is where you need to write your code for any ESP-IDF applications; it is the equivalent of the setup()<\/span> in Arduino programming. When the ESP32 boots, the ESP-IDF framework calls app_main<\/span>.<\/p>\n\n\n\nvoid app_main(void)\n{\n \/\/ your code goes here\n}<\/code><\/pre>\n\n\n\nIn the app_main(void)<\/span> function, you start by creating the GPIO config variable:<\/p>\n\n\n\ngpio_config_t io_conf = {\n .pin_bit_mask = (1ULL << LED_PIN), \/\/ Select GPIO 2\n .mode = GPIO_MODE_OUTPUT, \/\/ Set as output\n .pull_up_en = GPIO_PULLUP_DISABLE, \/\/ Disable pull-up\n .pull_down_en = GPIO_PULLDOWN_DISABLE, \/\/ Disable pull-down\n .intr_type = GPIO_INTR_DISABLE \/\/ Disable interrupts\n};<\/code><\/pre>\n\n\n\nThen, call the gpio_config(&io_conf)<\/span> function to configure the GPIO as an output, because we want to control its state with HIGH\/LOW.<\/p>\n\n\n\ngpio_config(&io_conf);<\/code><\/pre>\n\n\n\nThe while(1)<\/span> runs an infinite loop that ensures the LED will be blinking indefinitely. This is similar to the loop()<\/span> function in Arduino programming.<\/p>\n\n\n\nwhile (1) {\n \/\/ Turn LED ON\n printf(\"LED ON\\n\");\n gpio_set_level(LED_PIN, 1);\n vTaskDelay(1000 \/ portTICK_PERIOD_MS); \/\/ Delay 1 second\n\n \/\/ Turn LED OFF\n printf(\"LED OFF\\n\");\n gpio_set_level(LED_PIN, 0);\n vTaskDelay(1000 \/ portTICK_PERIOD_MS); \/\/ Delay 1 second\n};<\/code><\/pre>\n\n\n\nInside the infinite loop, you print a message saying “LED ON” in the Serial Monitor\/Terminal tab.<\/p>\n\n\n\n
printf(\"LED ON\\n\");<\/code><\/pre>\n\n\n\nSet the LED_PIN<\/span> level to 1<\/span> (it’s like setting to HIGH to turn the LED on).<\/p>\n\n\n\ngpio_set_level(LED_PIN, 1);<\/code><\/pre>\n\n\n\nThen, add a delay of 1000 milliseconds (1 second), so the LED is ON for 1 second before you turn it off to create the blink effect.<\/p>\n\n\n\n
vTaskDelay(1000 \/ portTICK_PERIOD_MS);<\/code><\/pre>\n\n\n\nA similar process is repeated to turn the LED off.<\/p>\n\n\n\n
\/\/ Turn LED OFF\nprintf(\"LED OFF\\n\");\ngpio_set_level(LED_PIN, 0);\nvTaskDelay(1000 \/ portTICK_PERIOD_MS); \/\/ Delay 1 second<\/code><\/pre>\n\n\n\nBuild and Flash Code to the ESP32 Board<\/h2>\n\n\n\n To build and flash ESP-IDF code to the ESP32, you always need to follow this procedure. You need to select the flash method (UART), the COM port number, the target device (ESP32), build the code, and finally, flash it to the board. All these commands are available in the bottom menu bar of VS Code.<\/p>\n\n\n\n
Make sure all your options are correct (they may already be properly configured if you used the project wizard).<\/p>\n\n\n
\n
However, if your setup is not correct, follow the next instructions to ensure everything is set up correctly. First, click the “Star<\/strong>” icon and select the flash method as UART<\/strong>.<\/p>\n\n\n\n
While the ESP32 board is connected to your computer, click the COM Port (plug icon) and select the correct port number that refers to your ESP32.<\/p>\n\n\n
\n
You also need to select the target device. Click on the chip icon at the bottom bar. In my case, I have an ESP32 with the esp32s3<\/strong> chip.<\/p>\n\n\n\n
For this board, I also need to select the configuration: ESP32-S chip (via builtin USB-JTAG)<\/strong>.<\/p>\n\n\n\n
Finally, your command bar on the bottom of VS Code should have similar options selected.<\/p>\n\n\n
\n
Now, you can build the project by clicking the wrench icon (Build Project<\/strong>) as shown in the image below.<\/p>\n\n\n\n
The first time you build a project, it usually takes a bit more time. Once completed, it should print a similar message in the Terminal<\/strong> menu and show a “Build Successfully<\/strong>” message.<\/p>\n\n\n\n
This is the final step. You can now flash the ESP-IDF project to the ESP32 by clicking the “Flash Device<\/strong>” button (thunder icon).<\/p>\n\n\n\n
Depending on your board, you might need to hold down the on-board BOOT button on your ESP32 to put into flashing mode. Once the process is completed, it will pop-up a info message saying “Flash Done<\/strong>“.<\/p>\n\n\n\n
Demonstration<\/h2>\n\n\n\n If you followed all the steps, the Blinking Code example should be running successfully on your board. Open your Terminal window \u2014 click the “Monitor Device<\/strong>” tool that is illustrated with a screen icon.<\/p>\n\n\n\n
The terminal should be printing a message saying “LED ON<\/strong>” and “LED OFF<\/strong>“. This process is repeated indefinitely.<\/p>\n\n\n\n
Your board is now running a basic LED blinking example. It will turn on GPIO 2 (blue LED labelled as IO2 in this particular board) for 1 second.<\/p>\n\n\n
\n
Then, it will turn it off for 1 second.<\/p>\n\n\n
\n
Example #2: Simple Blink LED with ESP-IDF<\/h2>\n\n\n\n Instead of using the gpio_config()<\/span> function with a gpio_config_t<\/span> structure, you can also control an output by simply resetting the pin and set the direction to output. Here’s the full main.c<\/em> code that blinks the ESP32 on-board LED:<\/p>\n\n\n\/* \n Rui Santos & Sara Santos - Random Nerd Tutorials\n https:\/\/RandomNerdTutorials.com\/esp-idf-esp32-blink-led\/\n Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files.\n The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.\n*\/\n\n#include <stdio.h>\n#include "freertos\/FreeRTOS.h"\n#include "freertos\/task.h"\n#include "driver\/gpio.h"\n#include "sdkconfig.h"\n\n\/\/ Define the GPIO pin for the LED (GPIO 2 is common for onboard LEDs)\n#define BLINK_GPIO 2\n\nvoid app_main(void)\n{\n \/\/ Configure the GPIO pin\n gpio_reset_pin(BLINK_GPIO);\n gpio_set_direction(BLINK_GPIO, GPIO_MODE_OUTPUT);\n\n \/\/ Blink loop\n while (1) {\n \/\/ Turn LED ON\n printf("LED ON\\n");\n gpio_set_level(BLINK_GPIO, 1);\n vTaskDelay(1000 \/ portTICK_PERIOD_MS); \/\/ Delay 1 second\n\n \/\/ Turn LED OFF\n printf("LED OFF\\n");\n gpio_set_level(BLINK_GPIO, 0);\n vTaskDelay(1000 \/ portTICK_PERIOD_MS); \/\/ Delay 1 second\n }\n}\n<\/code><\/pre>\n\tView raw code<\/a><\/p>\n\n\n\nHow the Code Works<\/h3>\n\n\n\n Libraries<\/strong><\/p>\n\n\n\nWe start by including the required libraries as shown in the previous example:<\/p>\n\n\n\n
#include <stdio.h>\n#include <freertos\/FreeRTOS.h>\n#include <freertos\/task.h>\n#include <driver\/gpio.h>\n#include \"sdkconfig.h\"<\/code><\/pre>\n\n\n\nPin Assignment<\/strong><\/p>\n\n\n\nThis line assigns the on-board LED to GPIO 2<\/span>; you can change it to a different number to match your board pinout or to control a different GPIO.<\/p>\n\n\n\n#define BLINK_GPIO 2<\/code><\/pre>\n\n\n\napp_main(void)<\/strong><\/p>\n\n\n\nInside the app_main(void)<\/span> function, you start by clearing the previous configurations for the BLINK_GPIO<\/span>:<\/p>\n\n\n\ngpio_reset_pin(BLINK_GPIO);<\/code><\/pre>\n\n\n\nYou configure the BLINK_GPIO<\/span> as an output, because we want to control its state with HIGH\/LOW.<\/p>\n\n\n\ngpio_set_direction(BLINK_GPIO, GPIO_MODE_OUTPUT);<\/code><\/pre>\n\n\n\nThe while(1)<\/span> runs an infinite loop that ensures the LED will be blinking indefinitely.<\/p>\n\n\n\nwhile (1) {\n \/\/ Turn LED ON\n printf(\"LED ON\\n\");\n gpio_set_level(BLINK_GPIO, 1);\n vTaskDelay(1000 \/ portTICK_PERIOD_MS); \/\/ Delay 1 second\n\n \/\/ Turn LED OFF\n printf(\"LED OFF\\n\");\n gpio_set_level(BLINK_GPIO, 0);\n vTaskDelay(1000 \/ portTICK_PERIOD_MS); \/\/ Delay 1 second\n};<\/code><\/pre>\n\n\n\nYou can build and flash the code into your ESP32, and it should run exactly as illustrated in example #1.<\/p>\n\n\n\n
Example #3: Control Multiple ESP32 GPIOs with ESP-IDF<\/h2>\n\n\n\n If you want to declare and configure multiple GPIOs at once, I recommend using the gpio_config()<\/span> function with a gpio_config_t<\/span> structure as shown in example #1. Here’s the full main.c<\/em> code that turns 3 GPIO pins of the ESP32 on and off:<\/p>\n\n\n\/* \n Rui Santos & Sara Santos - Random Nerd Tutorials\n https:\/\/RandomNerdTutorials.com\/esp-idf-esp32-gpio-outputs\/\n*\/\n\n#include <stdio.h>\n#include <freertos\/FreeRTOS.h>\n#include <freertos\/task.h>\n#include <driver\/gpio.h>\n#include "sdkconfig.h"\n\n#define LED_PIN_1 2\n#define LED_PIN_2 4\n#define LED_PIN_3 5\n\nvoid app_main(void)\n{\n \/\/ Configure multiple GPIOs\n gpio_config_t io_conf = {\n .pin_bit_mask = (1ULL << LED_PIN_1) | (1ULL << LED_PIN_2) | (1ULL << LED_PIN_3),\n .mode = GPIO_MODE_OUTPUT,\n .pull_up_en = GPIO_PULLUP_DISABLE,\n .pull_down_en = GPIO_PULLDOWN_DISABLE,\n .intr_type = GPIO_INTR_DISABLE\n };\n gpio_config(&io_conf);\n\n while (1) {\n \/\/ Turn all LEDs ON\n gpio_set_level(LED_PIN_1, 1);\n gpio_set_level(LED_PIN_2, 1);\n gpio_set_level(LED_PIN_3, 1);\n vTaskDelay(1000 \/ portTICK_PERIOD_MS);\n\n \/\/ Turn all LEDs OFF\n gpio_set_level(LED_PIN_1, 0);\n gpio_set_level(LED_PIN_2, 0);\n gpio_set_level(LED_PIN_3, 0);\n vTaskDelay(1000 \/ portTICK_PERIOD_MS);\n }\n}\n<\/code><\/pre>\n\tView raw code<\/a><\/p>\n\n\n\nHow the Code Works<\/h3>\n\n\n\n Libraries<\/strong><\/p>\n\n\n\nFirst, include the required libraries:<\/p>\n\n\n\n
#include <stdio.h>\n#include <freertos\/FreeRTOS.h>\n#include <freertos\/task.h>\n#include <driver\/gpio.h>\n#include \"sdkconfig.h\"<\/code><\/pre>\n\n\n\nPin Assignment<\/strong><\/p>\n\n\n\nThis line assigns the 3 pins to GPIO 2, GPIO 4, and GPIO 5.<\/p>\n\n\n\n
#define LED_PIN_1 2\n#define LED_PIN_2 4\n#define LED_PIN_3 5<\/code><\/pre>\n\n\n\n
![\"ESP-IDF:](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/07\/ESP32-ESP-IDF-Digital-Outputs.jpg?resize=1200%2C675&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"ESP-IDF](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/05\/ESP-IDF-ESP32-Create-Open-New-Project-Wizard-Menu.png?resize=937%2C742&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"ESP-IDF](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/05\/ESP-IDF-ESP32-Create-Open-New-Project-Wizard-Menu-Select-Directory-Board-Template.png?resize=983%2C856&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"ESP-IDF](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2026\/01\/ESP-IDF-ESP32-Create-New-Sample-Project-using-IDF-Template.png?resize=1178%2C744&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"ESP-IDF](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2026\/01\/ESP-IDF-ESP32-Open-New-Project-Sample.png?resize=1024%2C503&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"ESP-IDF](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/05\/ESP-IDF-ESP32-Open-Project-Folder-VS-Code-File-Menu.png?resize=396%2C315&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"ESP-IDF](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/05\/ESP-IDF-ESP32-Open-Project-VS-Code-Select-Folder.png?resize=667%2C366&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"ESP-IDF](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/05\/ESP-IDF-ESP32-Open-Project-in-a-VS-Code-Browse-to-Main-C-File.png?resize=907%2C571&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"VS](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/05\/VS-Code-Check-All-the-Configured-Settings-UART-COM-Port-Target-Board.png?resize=498%2C28&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"VS](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/05\/VS-Code-Select-Flash-UART-Option-to-Program-Flash-ESP32-1024x584.png?resize=1024%2C584&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"VS](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/05\/VS-Code-Programming-ESP32-Board-Select-Correct-COM-Port-Number.png?resize=1024%2C582&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"VS](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/05\/VS-Code-Select-the-ESP32-S3-or-Correct-Target-Device.png?resize=1024%2C579&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"VS](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/05\/VS-Code-Select-the-ESP32-S3-chip-via-built-in-USB-JTAG-Target-Device.png?resize=757%2C579&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"VS](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/06\/VS-Code-Build-Project-Example-Code-ESP32-ESP-IDF.png?resize=581%2C359&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"VS](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/06\/VS-Code-Build-Example-Project-ESP32-ESP-IDF-Success-Message.jpg?resize=648%2C468&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"VS](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/05\/VS-Code-Flash-Hello-World-Code-Project-to-ESP32-ESP-IDF.png?resize=848%2C170&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"VS](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/05\/VS-Code-Flash-Hello-Wolrd-Project-to-ESP32-ESP-IDF-Done-Success-Message.png?resize=1024%2C575&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"VS](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/05\/VS-Code-Open-Terminal-Window-Monitor-Device-ESP32-ESP-IDF.png?resize=780%2C77&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"ESP-IDF](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/05\/ESP-IDF-ESP32-Project-VS-Code-Open-Terminal-Window-Monitor-Test-Blink-Code-Example.png?resize=801%2C353&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"ESP32-S3](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/06\/ESP32-S3-Blink-On-Board-LED-ESP-IDF-ON.jpg?resize=750%2C422&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n![\"ESP32-S3](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2025\/06\/ESP32-S3-Blink-On-Board-LED-ESP-IDF-OFF.jpg?resize=750%2C421&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n