esp-idf/examples/get-started/blink

Blink Example

(See the README.md file in the upper level 'examples' directory for more information about examples.)

This example demonstrates how to blink a LED using GPIO or RMT for the addressable LED, i.e. WS2812.

See the RMT examples in the RMT Peripheral for more information about how to use it.

How to Use Example

Before project configuration and build, be sure to set the correct chip target using idf.py set-target <chip_name>.

Hardware Required

• A development board with ESP32/ESP32-S2/ESP32-S3/ESP32-C3 SoC (e.g., ESP32-DevKitC, ESP-WROVER-KIT, etc.)
• A USB cable for Power supply and programming

Some development boards use an addressable LED instead of a regular one. These development boards include:

Board	LED type	Pin
ESP32-C3-DevKitC-1	Addressable	GPIO8
ESP32-C3-DevKitM-1	Addressable	GPIO8
ESP32-S2-DevKitM-1	Addressable	GPIO18
ESP32-S2-Saola-1	Addressable	GPIO18
ESP32-S3-Addax-1	Addressable	GPIO48

See Development Boards for more information about it.

Configure the Project

Open the project configuration menu (idf.py menuconfig).

In the Example Configuration menu:

• Select the LED type in the Blink LED type option.
  • Use GPIO for regular LED blink.
  • Use RMT for addressable LED blink.
    • Use RMT Channel to select the RMT peripheral channel.
• Set the GPIO number used for the signal in the Blink GPIO number option.
• Set the blinking period in the Blink period in ms option.

Build and Flash

Run idf.py -p PORT flash monitor to build, flash and monitor the project.

(To exit the serial monitor, type Ctrl-].)

See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.

Example Output

As you run the example, you will see the LED blinking, according to the previously defined period. For the addressable LED, you can also change the LED color by setting the pStrip_a->set_pixel(pStrip_a, 0, 16, 16, 16); (LED Strip, Pixel Number, Red, Green, Blue) with values from 0 to 255 in the blink.c file.

I (315) example: Example configured to blink addressable LED!
I (325) example: Turning the LED OFF!
I (1325) example: Turning the LED ON!
I (2325) example: Turning the LED OFF!
I (3325) example: Turning the LED ON!
I (4325) example: Turning the LED OFF!
I (5325) example: Turning the LED ON!
I (6325) example: Turning the LED OFF!
I (7325) example: Turning the LED ON!
I (8325) example: Turning the LED OFF!

Note: The color order could be different according to the LED model.

The pixel number indicates the pixel position in the LED strip. For a single LED, use 0.

Troubleshooting

• If the LED isn't blinking, check the GPIO or the LED type selection in the Example Configuration menu.

For any technical queries, please open an issue on GitHub. We will get back to you soon.