prototipare col raspberry pi
TRANSCRIPT
Perché?
Il costo?
La potenza?
I linguaggi o i vari sistemi operativi?
LA COMUNITA’ ONLINE!!!
Sensori
Motori
Principali Sistemi Operativi
Raspbian (da Debian)
Ubuntu Mate
Snappy Ubuntu Core
Arch Linux Arc
Gentoo
Debian ARM
Windows 10 IoT (Pi 2)
Principali linguaggi con libreria per la GPIO
Python (RPi.GPIO)
C (wiringPi)
Processing (processing.io.*)
Java (Pi4J)
da riga di comando o Bash usando i relativi files (/sys/class/gpio/….)
La GPIO
Nomenclatura dei pin
Accendereun LED
Accendere un LEDimport RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BOARD)
GPIO.setup(7, GPIO.OUT)
# ciclo 10 volte, on/off di 1 sec.
for i in range(10):
GPIO.output(7,True)
time.sleep(1)
GPIO.output(7,False)
time.sleep(1)
GPIO.cleanup()
Accendere un LED
Pulsanti
PulsantiPull Down
Pull Up
Pulsantiimport RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BCM) # Broadcom SOC channel
GPIO.setup(4, GPIO.IN, pull_up_down=GPIO.PUD_UP)
while True:
input_state = GPIO.input(4)
if input_state == False:
print('Pulsante premuto')
time.sleep(0.5)
I2C (inter integrated circuit)
MAX112
I2C
I2C
I2C
IC2 #!/usr/bin/python
import smbus
bus = smbus.SMBus(1) # 0 oppure 1 se RPi è 256 o 512 Mb di RAM
DEVICE_ADDRESS = 0x70 # indirizzo 7 bit
DEVICE_REG_MODE1 = 0x00
DEVICE_REG_LEDOUT0 = 0x1d
#Scrive un singolo char [long write_byte_data(int addr,char cmd,char val)]
bus.write_byte_data(DEVICE_ADDRESS, DEVICE_REG_MODE1, 0x80)
#Lettura
(msb, lsb, xsb) = bus.read_i2c_block_data(addr, REG_MSB, 3)
PWM (pulse-width modulation)
PWM (duty-cycle)
PWM
def color(R, G, B): # range colore da 0-100% RED.ChangeDutyCycle(R) GREEN.ChangeDutyCycle(G) BLUE.ChangeDutyCycle(B)
# spegne tutti i LED time.sleep(.02) RED.ChangeDutyCycle(0) GREEN.ChangeDutyCycle(0) BLUE.ChangeDutyCycle(0)
# Settaggio dei pin come outputGPIO.setup(17, GPIO.OUT)GPIO.setup(18, GPIO.OUT)GPIO.setup(27, GPIO.OUT) RED = GPIO.PWM(17, 100) # 100HzRED.start(0) # 0 = spentoGREEN = GPIO.PWM(18, 100)GREEN.start(0)BLUE = GPIO.PWM(27, 100)BLUE.start(0)
while 1: for r in range(0,2): for g in range(0,2): for b in range(0,2): # loop per il 100% di ogni colore for i in range(0,101): color((x*i),(y*i),(z*i))
SPI (serial peripheral interface)
SPI
SPI#!/usr/bin/python
import spidev
import time
spi = spidev.SpiDev()
spi.open(0, 0)
spi.max_speed_hz = 7629
# Divide un intero in un array di 2 byte per spedirlo via SPI
def write_pot(input):
msb = input >> 8
lsb = input & 0xFF
spi.xfer([msb, lsb])
# Loop infinito di apertura/chiusura della porta del MCP4151
while True:
write_pot(0x1FF)
time.sleep(0.5)
write_put(0x00)
time.sleep(0.5)
UART Universal Async. Receiver-Transmitter
UART
UARTimport serial
ser = serial.Serial("/dev/ttyAMA0")
ser.write("messaggio da spedire")
read = ser.read()
print read
ser.close()