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| 1 | +# Empezando con micropython en ESP8266/32 |
| 2 | + |
| 3 | +<img src="media/Esp32-pinout.jpg" width="50%"> |
| 4 | + |
| 5 | +<img src="media/Esp8266-pinout.jpg" width="50%"> |
| 6 | + |
| 7 | +# Acceso a pines |
| 8 | + |
| 9 | +## SALIDAD DIGITAL (leds, reles) |
| 10 | + |
| 11 | +```py |
| 12 | +from machine import Pin |
| 13 | + |
| 14 | +pin = Pin(0, Pin.OUT) |
| 15 | + |
| 16 | +# hay dos variantes para cambiar el estado |
| 17 | +# con on/off y con 1/0 |
| 18 | + |
| 19 | +pin.on() |
| 20 | +pin.off() |
| 21 | + |
| 22 | +pin.value(1) |
| 23 | +pin.value(0) |
| 24 | +``` |
| 25 | + |
| 26 | +## ENTRADA DIGITAL (botones) |
| 27 | + |
| 28 | +```py |
| 29 | +from machine import Pin |
| 30 | + |
| 31 | +pin = Pin(2, Pin.IN) |
| 32 | + |
| 33 | +#para imprimir y leer el valor del pin |
| 34 | +print(pin.value()) |
| 35 | +``` |
| 36 | + |
| 37 | +## Modulación por ancho de pulsos - PWM (pulse width modulation) |
| 38 | + |
| 39 | +```py |
| 40 | +from machine import Pin, PWM |
| 41 | + |
| 42 | +pwm = PWM(Pin(0)) # Creamos el pin PWM |
| 43 | +pwm.freq(1000) # establecemos la frecuencia |
| 44 | +pwm.duty(200) # establecemos el ciclo de trabajo |
| 45 | + |
| 46 | +pwm.deinit() # apagamos el pin PWM |
| 47 | +``` |
| 48 | +Para crear y configura el pin en un solo paso |
| 49 | + |
| 50 | +```py |
| 51 | +from machine import Pin, PWM |
| 52 | + |
| 53 | +pwm = PWM(Pin(0), freq=20000, duty=512) |
| 54 | +``` |
| 55 | +## Conversor Analógico Digital - ADC (analog to digital conversion) |
| 56 | + |
| 57 | +```py |
| 58 | +from machine import ADC |
| 59 | + |
| 60 | +adc = ADC(Pin(32)) |
| 61 | +adc.read() |
| 62 | +``` |
| 63 | +## I2C |
| 64 | + |
| 65 | +Hay dos formas de usar el bus I2C en los ESPXX: |
| 66 | + |
| 67 | +SPI por hardware (cuando usamos los pines definidos como SDA y SCL del ESP para esta función) |
| 68 | + |
| 69 | +```py |
| 70 | +from machine import Pin, I2C |
| 71 | + |
| 72 | +i2c = I2C(0) |
| 73 | +i2c = I2C(1, scl=Pin(5), sda=Pin(4), freq=40000) |
| 74 | +#escaneamos nuestros sensores |
| 75 | +i2c.scan() |
| 76 | +``` |
| 77 | +SPI por software(cuando usamos pines diferentes de nuestra tarjeta) |
| 78 | + |
| 79 | +```py |
| 80 | +from machine import Pin, I2C |
| 81 | + |
| 82 | +i2c = I2C(scl=Pin(5), sda=Pin(4), freq=100000) |
| 83 | +#escaneamos nuestros sensores |
| 84 | +i2c.scan() |
| 85 | +``` |
| 86 | + |
| 87 | +NEOPIXEL leds programables |
| 88 | + |
| 89 | + |
| 90 | +```py |
| 91 | +from machine import Pin |
| 92 | +from neopixel import NeoPixel |
| 93 | + |
| 94 | +#establecemos el número del pin GPIO la que estan los leds |
| 95 | +#establememos la cantidad de leds que hay |
| 96 | + |
| 97 | +pin = Pin(0, Pin.OUT) |
| 98 | +np = NeoPixel(pin, 8) |
| 99 | + |
| 100 | +#para encender un led es necesario indicar la posición de este |
| 101 | + |
| 102 | +np[0] = (255, 255, 255) |
| 103 | + |
| 104 | +#con np.write actualizamos los leds |
| 105 | +np.write() |
| 106 | +``` |
| 107 | + |
| 108 | +ejemplo con un for para encender varios leds de una tira neopixel |
| 109 | + |
| 110 | +```py |
| 111 | +num_leds=10 |
| 112 | +pin_salida=15 |
| 113 | +np = neopixel.NeoPixel(machine.Pin(pin_salida), num_leds) |
| 114 | + |
| 115 | +for led in range(num_leds): |
| 116 | + np[led]=(255,0,0) |
| 117 | +np.write() |
| 118 | + |
| 119 | +``` |
| 120 | + |
| 121 | +WiFi conexión robusta |
| 122 | + |
| 123 | +```py |
| 124 | +#CONEXION A LA RED WIFI |
| 125 | +# Informacion de la red WiFi |
| 126 | +WIFI_SSID = '' |
| 127 | +WIFI_PASSWORD = '' |
| 128 | + |
| 129 | +# apagar el punto de acceso WiFi |
| 130 | +ap_if = network.WLAN(network.AP_IF) |
| 131 | +ap_if.active(False) |
| 132 | + |
| 133 | +# conecta el dispositivo a la red WiFi |
| 134 | +wifi = network.WLAN(network.STA_IF) |
| 135 | +wifi.active(True) |
| 136 | +wifi.connect(WIFI_SSID, WIFI_PASSWORD) |
| 137 | + |
| 138 | +# esperar hasta que el dispositivo esté conectado a la red WiFi |
| 139 | +MAX_ATTEMPTS = 20 |
| 140 | +attempt_count = 0 |
| 141 | + |
| 142 | +while not wifi.isconnected() and attempt_count < MAX_ATTEMPTS: |
| 143 | + attempt_count += 1 |
| 144 | + time.sleep(1) |
| 145 | + print('conectando a la red WiFi...') |
| 146 | + |
| 147 | +if attempt_count == MAX_ATTEMPTS: |
| 148 | + print('no se pudo conectar a la red WiFi') |
| 149 | + sys.exit() |
| 150 | + |
| 151 | +print('conectado a la red WiFi') |
| 152 | +print ("Configuracion de red: ", wifi.ifconfig()) |
| 153 | +``` |
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