Page 11 of 16
Page 212
import dht
from machine import Pin
from time import sleep
dht = dht.DHT22(Pin(23))
while True:
dht.measure()
temp = dht.temperature()
print(temp,"C")
hum = dht.humidity()
print(hum,"%")
sleep(1)
Page 213
from machine import Pin
from utime import sleep_ms
DHT = Pin(23,mode=Pin.OUT,value=1)
sleep_ms(1)
DHT.off()
sleep_ms(1)
DHT.init(mode=Pin.IN)
Page 217
from machine import Pin,time_pulse_us
from utime import sleep_ms
class DHT22():
def __init__(self,gpio):
self.pin = Pin(gpio, mode=Pin.IN)
self.checksum = 0
self.temperature = 0
self.humidity=0
sleep_ms(1)
@micropython.native
def getReading(self):
data = 0
checksum = 0
DHT=self.pin
DHT.init(mode=Pin.OUT,value=0)
sleep_ms(1)
DHT.init(mode=Pin.IN)
t = time_pulse_us(DHT, 0, 1000)
t = time_pulse_us(DHT, 1, 1000)
for i in range(32):
t = time_pulse_us(DHT, 1, 1000)
data = data << 1
data = data | (t > 50)
for i in range(8):
t = time_pulse_us(DHT, 1, 1000)
checksum = checksum << 1
checksum = checksum |(t > 50)
byte1 = (data >> 24 & 0xFF)
byte2 = (data >> 16 & 0xFF)
byte3 = (data >> 8 & 0xFF)
byte4 = (data & 0xFF)
self.checksum =(checksum ==(byte1+byte2+byte3+byte4)&0xFF)
self.humidity = ((byte1 <<8)| byte2) / 10.0
neg = byte3 & 0x80
byte3 = byte3 & 0x7F
self.temperature = (byte3 << 8 | byte4) / 10.0
if neg > 0:
self.temperature = -self.temperature
dht = DHT22(23)
dht.getReading()
print("Checksum",dht.checksum)
print("Humidity= ", dht.humidity)
print("Temperature=", dht.temperature)
Page 223
from machine import Pin
import onewire,ds18x20
ow = onewire.OneWire(Pin(23))
presence=ow.reset()
if presence:
print("Device present")
else:
print("No device")
ds = ds18x20.DS18X20(ow)
roms = ds.scan()
t = ds.read_temp(roms[0])
print(t)
Page 230
from machine import Pin
import onewire
class DS18B20:
def __init__(self,pin):
self.ow = onewire.OneWire(Pin(pin))
def __convert(self):
self.ow.write([0xCC,0x44])
for i in range(500):
sleep_ms(10)
if self.ow.readbit() == 1:
j = i
break
return j
def getTemp(self):
if not self.ow.reset:
return -1000
if self.__convert()==500:
return -3000
self.ow.reset()
self.ow.write([0xCC,0xBE])
data = bytearray(9)
self.ow.readinto(data)
if self.ow.crc8(data)!=0:
return -2000
t1 = data[0]
t2 = data[1]
temp1 = (t2 << 8 | t1)
if t2 & 0x80:
temp1=temp1 | 0xFFFF0000
return temp1/16
dS18B20=DS18B20(23)
print(dS18B20.getTemp())
