{"id":1384,"date":"2024-05-01T19:38:58","date_gmt":"2024-05-01T19:38:58","guid":{"rendered":"https:\/\/raymundopizano.com\/blog\/?p=1384"},"modified":"2024-09-15T21:05:57","modified_gmt":"2024-09-15T21:05:57","slug":"arduino-7-apagar-gradualmente-un-led","status":"publish","type":"post","link":"https:\/\/raymundopizano.com\/blog\/arduino\/arduino-7-apagar-gradualmente-un-led\/","title":{"rendered":"Arduino – 7. Apagar gradualmente un LED"},"content":{"rendered":"\n

Hemos visto hasta el momento las salidas digitales las cuales solo tiene dos valores posibles 1 HIGH<\/strong> (encendido<\/em>) y 0 LOW <\/strong>(apagado<\/em>) con la funci\u00f3n digitalWrite(PIN, HIGH \/ LOW);<\/code>., tambi\u00e9n existen los tipos de salidas anal\u00f3gicas PWM <\/strong>(Pulse Width Modulation \/ Modulaci\u00f3n por Ancho de Pulsos<\/em>) las cuales van de un rango de 0 a 255 y podemos usar la funci\u00f3n analogWrite(PIN,VALOR);<\/code> para controlar la salida.<\/p>\n\n\n\n

No todos los pines de nuestro Arduino se puede usar como salidas anal\u00f3gicas., las que son est\u00e1n marcadas con una ~ virgulilla a un lado del numero del pin.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Gracias a estas podemos controlar el voltaje que sale de un pin y son muy \u00fatiles para controlar la velocidad de un motor el\u00e9ctrico<\/strong>, el brillo de un LED<\/strong> y controlar un servomotor<\/strong>.<\/p>\n\n\n\n

<\/p>\n\n\n\n

Modelos de tarjetas Pines y Frecuencias <\/h3>\n\n\n\n
TARJETA<\/th>PWM PINS *<\/th>PWM FRECUENCIA<\/th><\/tr><\/thead>
UNO (R3 and earlier), Nano, Mini<\/td>3, 5, 6, 9, 10, 11<\/td>490 Hz (pins 5 and 6: 980 Hz)<\/td><\/tr>
UNO R4 (Minima, WiFi) *<\/td>3, 5, 6, 9, 10, 11<\/td>490 Hz<\/td><\/tr>
Mega<\/td>2 – 13, 44 – 46<\/td>490 Hz (pins 4 and 13: 980 Hz)<\/td><\/tr>
GIGA R1 **<\/td>2 – 13<\/td>500 Hz<\/td><\/tr>
Leonardo, Micro, Y\u00fan<\/td>3, 5, 6, 9, 10, 11, 13<\/td>490 Hz (pins 3 and 11: 980 Hz)<\/td><\/tr>
UNO WiFi Rev2, Nano Every<\/td>3, 5, 6, 9, 10<\/td>976 Hz<\/td><\/tr>
MKR boards *<\/td>0 – 8, 10, A3, A4<\/td>732 Hz<\/td><\/tr>
MKR1000 WiFi **<\/td>0 – 8, 10, 11, A3, A4<\/td>732 Hz<\/td><\/tr>
Zero **<\/td>3 – 13, A0, A1<\/td>732 Hz<\/td><\/tr>
Nano 33 IoT **<\/td>2, 3, 5, 6, 9 – 12, A2, A3, A5<\/td>732 Hz<\/td><\/tr>
Nano 33 BLE\/BLE Sense ****<\/td>1 – 13, A0 – A7<\/td>500 Hz<\/td><\/tr>
Due ***<\/td>2-13<\/td>1000 Hz<\/td><\/tr>
101<\/td>3, 5, 6, 9<\/td>pins 3 and 9: 490 Hz, pins 5 and 6: 980 Hz<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

<\/p>\n\n\n\n

\u00bfC\u00f3mo usar la funci\u00f3n analogWrite()?<\/h3>\n\n\n\n

Para generar se\u00f1ales PWM <\/strong>con Arduino se utiliza la funci\u00f3n analogWrite(PIN, VALOR);<\/code> donde el PIN<\/em> puede ser 3, 5, 6, 9, 10 y 11 (En nuestro Arduino Uno R3), y el VALOR <\/em>puede ir de 0 a 255, como podemos verlo en la siguiente tabla:<\/p>\n\n\n\n

Argumento analogWrite()<\/strong><\/th>Ciclo de trabajo<\/strong><\/th>Voltaje promedio<\/strong><\/th><\/tr><\/thead>
0<\/td>0%<\/td>0 V<\/td><\/tr>
63<\/td>25%<\/td>1,25 V<\/td><\/tr>
76<\/td>30%<\/td>1,5 V<\/td><\/tr>
127<\/td>50%<\/td>2,5 V<\/td><\/tr>
178<\/td>70%<\/td>3,5 V<\/td><\/tr>
191<\/td>75%<\/td>3,75 V<\/td><\/tr>
229<\/td>90%<\/td>4,5 V<\/td><\/tr>
255<\/td>100%<\/td>5 V<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

<\/p>\n\n\n\n

Apagado gradual de un LED<\/h2>\n\n\n\n

Requerimos<\/h3>\n\n\n\n
    \n
  • Tarjeta UNO R3<\/li>\n\n\n\n
  • Protoboard<\/li>\n\n\n\n
  • Led 5mm rojo<\/li>\n\n\n\n
  • Resistencia de 330\u03a9 Ohms<\/li>\n\n\n\n
  • Dos cables macho para protoboard o dupont<\/li>\n<\/ul>\n\n\n\n

    Conectamos un cable del Pin GND de la Tarjeta UNO R3 al c\u00e1todo (cable negro) y el Pin 11 a la resistencia, y la resistencia al \u00e1nodo del LED.<\/p>\n\n\n\n

    \"\"<\/figure>\n\n\n\n
    <\/circle><\/circle><\/circle><\/g><\/svg><\/span><\/path><\/path><\/svg><\/span>
    \/\/ Declaramos pinLed constante de tipo byte<\/span><\/span>\n\/\/ Y le asignamos el pin 11 que es una salida de tipo ~ PWM <\/span><\/span>\nconst<\/span> byte pinLed <\/span>=<\/span> <\/span>11<\/span>;<\/span><\/span>\n<\/span>\nvoid<\/span> <\/span>setup<\/span>()<\/span><\/span>\n{<\/span><\/span>\n  \/\/ Inicializamos el pin digital 11 de salida<\/span><\/span>\n  <\/span>pinMode<\/span>(pinLed, OUTPUT);<\/span><\/span>\n}<\/span><\/span>\n<\/span>\nvoid<\/span> <\/span>loop<\/span>()<\/span><\/span>\n{<\/span><\/span>\n  <\/span><\/span>\n  \/\/ analogWrite nos permite controlar el voltage<\/span><\/span>\n  \/\/ de 0 apagado a 100% los 5V<\/span><\/span>\n  <\/span><\/span>\n  \/\/ le damos un 60% de brillo al LED durante 200 milisegundos<\/span><\/span>\n  <\/span>analogWrite<\/span>(pinLed,<\/span>60<\/span>);<\/span><\/span>\n  <\/span>delay<\/span>(<\/span>200<\/span>);<\/span><\/span>\n  <\/span>analogWrite<\/span>(pinLed,<\/span>50<\/span>);<\/span><\/span>\n  <\/span>delay<\/span>(<\/span>200<\/span>);<\/span><\/span>\n  <\/span>analogWrite<\/span>(pinLed,<\/span>40<\/span>);<\/span><\/span>\n  <\/span>delay<\/span>(<\/span>200<\/span>);<\/span><\/span>\n  <\/span>analogWrite<\/span>(pinLed,<\/span>30<\/span>);<\/span><\/span>\n  <\/span>delay<\/span>(<\/span>200<\/span>);<\/span><\/span>\n  <\/span>analogWrite<\/span>(pinLed,<\/span>20<\/span>);<\/span><\/span>\n  <\/span>delay<\/span>(<\/span>200<\/span>);<\/span><\/span>\n  <\/span>analogWrite<\/span>(pinLed,<\/span>10<\/span>);<\/span><\/span>\n  <\/span>delay<\/span>(<\/span>200<\/span>);<\/span><\/span>\n  \/\/ hasta llegar a 0 con pausas de tiempo<\/span><\/span>\n  <\/span>analogWrite<\/span>(pinLed,<\/span>0<\/span>);<\/span><\/span>\n  <\/span>delay<\/span>(<\/span>1000<\/span>);<\/span><\/span>\n  \/\/ y se reinicia el ciclo loop<\/span><\/span>\n}<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
    Presiona el bot\u00f3n de Iniciar simulaci\u00f3n<\/code>, ve como enciende y apaga el LED, luego clic a <\/ C\u00f3digo<\/code>.<\/p>\n\n\n\n