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温度センサー DHT11、DHT22のサンプルコード
DHT11
回路、配線図
micropython @ESP32
ドライブのDHTをインポートして使える
import dht
import machine
d = dht.DHT11(machine.Pin(4))
d.measure()
d.temperature() # 例: 23 (°C)
d.humidity() # 例: 41 (% RH)
d = dht.DHT22(machine.Pin(4))
d.measure()
d.temperature() # 例: 23.6 (°C)
d.humidity() # 例: 41.3 (% RH)
micropython @RP2
上記のdhtはRP2では使えません！！
（温度を取得しても0となります）
こちらの記事を参考にします
以下、引用
class Dht11
class Dht11:
"""DHT11 temperature/humidity sensor IF class"""
def __init__(self, pinN):
self.dht11 = Pin(pinN, Pin.OPEN_DRAIN, Pin.PULL_UP)
self.dht11.value(1)
self.buf = []
self.temperature = None
self.humidity = None
self.crc = False
self.crcC = None
self.crcR = None
self.ERROR = 0
def startSignal(self):
self.dht11.value(0)
time.sleep_ms(19)
self.dht11.value(1)
time.sleep_us(20)
def waitSIG(self, sig, timeOut):
count = 0
while self.dht11.value() == sig:
count += 1
if count > timeOut:
return False
return True
def bitRead(self):
while self.dht11.value() == 0:
pass
if self.dht11.value() == 0:
return 0
if self.dht11.value() == 0:
return 0
if self.dht11.value() == 0:
return 0
if self.dht11.value() == 0:
return 0
if self.dht11.value() == 0:
return 0
if self.dht11.value() == 0: #6
return 1
if self.dht11.value() == 0:
return 1
return 1
def b2B(self, lis):
work = 0
for i in lis:
work <<=1
work += i
return work
def convertData(self):
rhI = self.b2B(self.buf[0:7])
rhD = self.b2B(self.buf[7:15])
tmI = self.b2B(self.buf[15:23])
tmD = self.b2B(self.buf[23:31])
self.crcR = self.b2B(self.buf[31:39])
self.crcC = (rhI + rhD + tmI + tmD) & 0xFF
if self.crcR == self.crcC:
self.crc = True
else:
self.crc = False
self.temperature = (tmI & 0x7F) + (tmD / 10)
if tmI & 0x80:
self.temperature *= -1
self.humidity = rhI + (rhD / 10 )
self.buf.clear()
def read(self):
self.ERROR = 0
self.startSignal()
if not self.waitSIG(0, 100):
self.ERROR = 1
return False
if not self.waitSIG(1, 1000):
self.ERROR = 2
return False
if not self.waitSIG(0, 1000):
self.ERROR = 3
return False
for idx in range(40):
b1 = self.bitRead()
self.buf.append(b1)
self.convertData()
return True
main.py
dht11 = Dht11(17)
DHT22 micropython @RP2
こちらのライブラリを使います
DHT22.py
DHT22.py
'''
*
*
* The MIT License (MIT)
*
* Copyright (c) 2021 Daniel Perron
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
'''
import utime
import rp2
from rp2 import PIO, asm_pio
from machine import Pin
#
# A B C D E F
# ___ ___ ...
# ____/ \___/ \___/ \
#
# A = start pulse (> 1ms )
# B = 2-40 us
# C = 80 us
# D = 80 us
#
# E and F are data clock
#
# E = 50 us
# F = 26-28 us => 0 70 us => 1
#
@asm_pio(set_init=(PIO.OUT_HIGH),autopush=True, push_thresh=8)
def DHT22_PIO():
# clock set at 500Khz Cycle is 2us
# drive output low for at least 20ms
set(y,1) # 0
pull() # 1
mov(x,osr) # 2
set(pindirs,1) # 3 set pin to output
set(pins,0) # 4 set pin low
label ('waitx')
jmp(x_dec,'waitx') # 5 decrement x reg every 32 cycles
set(pindirs,0) # 6 set pin to input
# STATE A. Wait for high at least 80us. max should be very short
set(x,31) # 7
label('loopA')
jmp(pin,'got_B') # 8
jmp(x_dec,'loopA') # 9
label('Error')
in_(y,1) # 10
jmp('Error') # 11 Infinity loop error
# STATE B. Get HIGH pulse. max should be 40us
label('got_B')
set(x,31) # 12
label('loop_B')
jmp(x_dec,'check_B') # 13
jmp('Error') # 14
label('check_B')
jmp(pin,'loop_B') # 15
# STATE C. Get LOW pulse. max should be 80us
set(x,31) # 16
label('loop_C')
jmp(pin,'got_D') # 17
jmp(x_dec,'loop_C') # 18
jmp('Error') # 19
# STATE D. Get HIGH pulse. max should be 80us
label('got_D')
set(x,31) # 20
label('loop_D')
jmp(x_dec,'check_D') # 21
jmp('Error') # 22
label('check_D')
jmp(pin,'loop_D') # 23
# STATE E. Get Low pulse delay. should be around 50us
set(x,31) # 24
label('loop_E')
jmp(pin,'got_F') # 25
jmp(x_dec,'loop_E') # 26
jmp('Error') # 27
# STATE F.
# wait 40 us
label('got_F')
nop() [20] # 28
in_(pins,1) # 29
# now wait for low pulse
set(x,31) # 30
jmp('loop_D') # 31
class PicoDHT22:
def __init__(self,dataPin, powerPin=None,dht11=False,smID=1):
self.dataPin = dataPin
self.powerPin = powerPin
self.dht11 = dht11
self.smID = smID
self.dataPin.init(Pin.IN, Pin.PULL_UP)
if self.powerPin is not None:
self.powerPin.init(Pin.OUT)
self.powerPin.value(0)
self.sm= rp2.StateMachine(self.smID)
def read_array(self):
if self.powerPin is not None:
self.powerPin.value(1)
utime.sleep_ms(800)
utime.sleep_ms(200)
#start state machine
self.sm.init(DHT22_PIO,freq=500000,
set_base=self.dataPin,
in_base=self.dataPin,
jmp_pin=self.dataPin)
if self.dht11:
self.sm.put(10000)
else:
self.sm.put(1000)
self.sm.active(1)
value = []
for i in range(5):
value.append(self.sm.get())
self.sm.active(0)
if self.powerPin is not None:
self.powerPin.value(0)
return value
def read(self):
value = self.read_array()
sumV = 0
for i in range(4):
sumV += value[i]
if (sumV & 0xff) == value[4]:
if self.dht11:
humidity=value[0] & 0x7f
temperature=value[2]
else:
humidity=((value[0]<<8) + value[1])/10.0
temperature=(((value[2] &0x7f) << 8) + value[3]) /10.0
if (value[2] & 0x80) == 0x80:
temperature = -temperature
return temperature, humidity
else:
return None, None
if __name__ == "__main__":
from machine import Pin
from PicoDHT22 import PicoDHT22
import utime
dht_data = Pin(15,Pin.IN,Pin.PULL_UP)
dht_sensor=PicoDHT22(dht_data,Pin(14,Pin.OUT),dht11=False)
while True:
T,H = dht_sensor.read()
if T is None:
print(" sensor error")
else:
print("{:3.1f}'C {:3.1f}%".format(T,H))
#DHT22 not responsive if delay to short
utime.sleep_ms(500)
C/C++ @Arduino UNO
実行前にライブラリを追加する必要があります
サンプルコード
#include <dht11.h>
dht11 DHT11;
#define DHT11PIN 8
void setup()
{
Serial.begin(9600);
}
void loop()
{
DHT11.read(DHT11PIN);
Serial.print("Temperature=");
Serial.print(DHT11.temperature);
Serial.print(" C");
Serial.print('\t');
Serial.print("Humidity=%");
Serial.println(DHT11.humidity);
delay(500);
}
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