Project Description

This example shows how to control the intensity of LEDs using the standard ESP-IDF LEDC driver (a LED Controller using PWM):

• Frequency
• Duty resolution
• Duty cycle

Espressif Reference Documentation: https://esp-idf.readthedocs.io/en/latest/api-reference/peripherals/ledc.html

What are the HW SW requirements of the ESP32 MJD Starter Kit?

Hardware

• A decent ESP development board. I suggest to buy a popular development board with good technical documentation and a significant user base. Examples: Adafruit HUZZAH32, Espressif ESP32-DevKitC, Pycom WiPy, Wemos D32.
• The peripherals that are used in the project. @tip The README of each component contains a section "Shop Products". @example A Bosch BME280 meteo sensor breakout board.

Software: ESP-IDF v3.2

• A working installation of the Espressif ESP-IDF V3.2 development framework** (detailed instructions @ http://esp-idf.readthedocs.io/en/latest/get-started/index.html).

mkdir ~/esp
cd    ~/esp
git clone -b v3.3 --recursive https://github.com/espressif/esp-idf.git esp-idf-v3.2

• A C language editor or the Eclipse IDE CDT (instructions also @ http://esp-idf.readthedocs.io/en/latest/get-started/index.html).

FAQ

• LEDC: the available duty resolution steps = (2 ^ bit_num bit_num of the duty resolution) - 1
• LEDC: the maximal frequency is 80000000 / (2 ^ bit_num of the duty resolution)
• https://physics.stackexchange.com/questions/19040/limit-of-human-eye-flicker-perception

Hardware Setup

• This setup uses a yellow LED with a Forward voltage of 2.0-2.2V. The resistor value of 100 Ohm is specific for the LED's forward voltage. If you use a LED with a higher Forward Voltage then you might have to lower the resistor value else the LED will not turn on.
• Wire ESP32's GPIO_NUM_14 -> (+) 5mm yellow LED (-) -> Resistor 100 Ohm -> GND

Running the example

• Run make flash monitor to build and upload the example to your board and connect to its serial terminal.

Reference: the ESP32 MJD Starter Kit SDK

Do you also want to create innovative IoT projects that use the ESP32 chip, or ESP32-based modules, of the popular company Espressif? Well, I did and still do. And I hope you do too.

The objective of this well documented Starter Kit is to accelerate the development of your IoT projects for ESP32 hardware using the ESP-IDF framework from Espressif and get inspired what kind of apps you can build for ESP32 using various hardware modules.

Go to https://github.com/pantaluna/esp32-mjd-starter-kit