![\"ESP8266](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2019\/07\/ESP8266-PWM-Thumbnail.jpg?resize=1200%2C675&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n\nTo generate a PWM signal on the ESP8266 pins with Arduino IDE, use analogWrite(pin, value)<\/span>. The value is an integer between 0 and 255.<\/p>\n\n\n\n For ESP8266 releases before 3.0, the default range is between 0 and 1023. The PWM range may be changed by calling analogWriteRange(new_range)<\/span>.<\/p>\n\n\n\n You might also like reading other guides about PWM:<\/p>\n\n\n\n Before proceeding with this tutorial you should have the ESP8266 add-on installed in your Arduino IDE. Follow the next tutorial to Install ESP8266 in Arduino IDE<\/a>.<\/p>\n\n\n\n The ESP8266 GPIOs can be set either to output 0V or 3.3V, but they can’t output any voltages in between. However, you can output “fake” mid-level voltages using pulse\u2011width modulation (PWM), which is how you\u2019ll produce varying levels of LED brightness for this project.<\/p>\n\n\n\n If you alternate an LED’s voltage between HIGH and LOW very fast, your eyes can’t keep up with the speed at which the LED switches on and off; you’ll simply see some gradations in brightness.<\/p>\n\n\n\n That’s basically how PWM works \u2014 by producing an output that changes between HIGH and LOW at a very high frequency. <\/p>\n\n\n\n The duty cycle is the fraction of the time period at which LED is set to HIGH. The following figure illustrates how PWM works.<\/p>\n\n\n\n A duty cycle of 50 percent results in 50 percent LED brightness, a duty cycle of 0 means the LED is fully off, and a duty cycle of 100 means the LED is fully on. Changing the duty cycle is how you produce different levels of brightness.<\/p>\n\n\n\n To produce a PWM signal on a given pin you use the following function:<\/p>\n\n\n\n You can change the PWM range by calling:<\/p>\n\n\n\n By default, ESP8266 PWM frequency is 1kHz. You can change PWM frequency with:<\/p>\n\n\n\n Valid values are from 100Hz to 40000Hz.<\/p>\n\n\n\n In this section, we’ll build a simple example that dims an LED so that you see how to use PWM in your projects. You’ll need the following parts:<\/p>\n\n\n\n If you’re using an ESP-01<\/a>, you need an FTDI programmer<\/a> or a Serial Adapter<\/a> to upload code.<\/p>\n\n\n You can use the preceding links or go directly to MakerAdvisor.com\/tools<\/a> to find all the parts for your projects at the best price!<\/p> After uploading the code, wire an LED to your ESP8266 as shown in the following schematic diagram. We’re connecting the LED to GPIO 2<\/span>, but you can use any other suitable GPIOs.<\/p>\n\n\n\n If you’re using an ESP-01, you can check the board pinout here<\/a>.<\/p>\n\n\n\n Copy the code to your Arduino IDE and upload it to your ESP8266.<\/p>\n\n\n View raw code<\/a><\/p>\n\n\n\n Continue reading this section to learn how the code works, or skip to the next section.<\/p>\n\n\n\n Start by defining the pin LED is attached to. In this case, LED is attached to GPIO 2<\/span> (D4).<\/p>\n\n\n\n In the loop()<\/span>, you vary the duty cycle between 0 and 255 to increase the LED brightness.<\/p>\n\n\n\n And then, between 255 and 0 to decrease brightness.<\/p>\n\n\n\n To set the LED brightness, you need to use analogWrite()<\/span> function that accepts as arguments GPIO where you want to get the PWM signal and a value between 0 and 255 to set the duty cycle. <\/p>\n\n\n\n In your Arduino IDE, go to Tools<\/strong> > Board<\/strong> and select your ESP8266 model (If you’re using an ESP-01, select “Generic ESP8266 Module”) . <\/p>\n\n\n\n Go to Tools<\/strong> > Port<\/strong> and select the COM port the ESP8266 is connected to.<\/p>\n\n\n\n If you’re using an ESP-01, you need an FTDI programmer or Serial Adapter to upload code. Here are the connections you need to make:<\/p>\n\n\n\nESP8266 NodeMCU PWM (Pulse-Width Modulation)<\/h2>\n\n\n\n
![\"ESP8266](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2019\/07\/led-fade.png?resize=895%2C182&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n\n![\"How](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2019\/07\/PWM-how-it-works.png?resize=711%2C658&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n\nanalogWrite()<\/h2>\n\n\n\n
analogWrite(pin, value);<\/code><\/pre>\n\n\n\nanalogWriteRange(new_range);<\/code><\/pre>\n\n\n\nanalogWriteFreq(new_frequency);<\/code><\/pre>\n\n\n\nESP8266 NodeMCU Dim LED with PWM<\/h2>\n\n\n\n
![](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2017\/10\/header-200.png?w=1200&quality=100&strip=all&ssl=1\")
<\/a><\/p>\n\n\n\nSchematic<\/h2>\n\n\n\n
![\"ESP8266](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2019\/07\/ESP8266_PWM_bb.png?resize=930%2C543&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n\nESP8266 NodeMCU PWM Code<\/h2>\n\n\n\n
\/*********\n Rui Santos\n Complete project details at https:\/\/randomnerdtutorials.com \n*********\/\n\nconst int ledPin = 2; \n\nvoid setup() {\n \n}\n\nvoid loop() {\n \/\/ increase the LED brightness\n for(int dutyCycle = 0; dutyCycle < 255; dutyCycle++){ \n \/\/ changing the LED brightness with PWM\n analogWrite(ledPin, dutyCycle);\n delay(1);\n }\n\n \/\/ decrease the LED brightness\n for(int dutyCycle = 255; dutyCycle > 0; dutyCycle--){\n \/\/ changing the LED brightness with PWM\n analogWrite(ledPin, dutyCycle);\n delay(1);\n }\n}\n<\/code><\/pre>\n\tHow the code works<\/h3>\n\n\n\n
const int ledPin = 2;<\/code><\/pre>\n\n\n\nfor(int dutyCycle = 0; dutyCycle < 255; dutyCycle++){ \n \/\/ changing the LED brightness with PWM\n analogWrite(ledPin, dutyCycle);\n delay(1);\n}<\/code><\/pre>\n\n\n\nfor(int dutyCycle = 255; dutyCycle > 0; dutyCycle--){\n \/\/ changing the LED brightness with PWM\n analogWrite(ledPin, dutyCycle);\n delay(1);\n}<\/code><\/pre>\n\n\n\nUpload the Code<\/h2>\n\n\n\n
![\"ESP8266](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2019\/07\/ESP-01-FTDI-Programmer.png?resize=975%2C212&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n\n
![\"ESP8266](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2019\/07\/ESP8266-PWM-Demo.jpg?resize=750%2C421&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n\n![\"ESP8266](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2019\/07\/PWM_signal_ESP8266_oscilloscope.png?resize=655%2C481&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n\n