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Python - SHT11.py
# Reference: https://github.com/2black0/micropython-sht11
from machine import Pin
import utime
class SHT11:
class AckException(Exception):
pass
class CRCException(Exception):
pass
MEASURE_T = 0b00000011
MEASURE_RH = 0b00000101
SOFT_RESET = 0b00011110
READ_STATUS_REGISTER = 0b000000111
WRITE_STATUS_REGISTER = 0b000000110
CLOCK_TIME_US = 10
CRC_TABLE = [
0, 49, 98, 83, 196, 245, 166, 151, 185, 136, 219, 234, 125, 76, 31, 46,
67, 114, 33, 16, 135, 182, 229, 212, 250, 203, 152, 169, 62, 15, 92, 109,
134, 183, 228, 213, 66, 115, 32, 17, 63, 14, 93, 108, 251, 202, 153, 168,
197, 244, 167, 150, 1, 48, 99, 82, 124, 77, 30, 47, 184, 137, 218, 235,
61, 12, 95, 110, 249, 200, 155, 170, 132, 181, 230, 215, 64, 113, 34, 19,
126, 79, 28, 45, 186, 139, 216, 233, 199, 246, 165, 148, 3, 50, 97, 80,
187, 138, 217, 232, 127, 78, 29, 44, 2, 51, 96, 81, 198, 247, 164, 149,
248, 201, 154, 171, 60, 13, 94, 111, 65, 112, 35, 18, 133, 180, 231, 214,
122, 75, 24, 41, 190, 143, 220, 237, 195, 242, 161, 144, 7, 54, 101, 84,
57, 8, 91, 106, 253, 204, 159, 174, 128, 177, 226, 211, 68, 117, 38, 23,
252, 205, 158, 175, 56, 9, 90, 107, 69, 116, 39, 22, 129, 176, 227, 210,
191, 142, 221, 236, 123, 74, 25, 40, 6, 55, 100, 85, 194, 243, 160, 145,
71, 118, 37, 20, 131, 178, 225, 208, 254, 207, 156, 173, 58, 11, 88, 105,
4, 53, 102, 87, 192, 241, 162, 147, 189, 140, 223, 238, 121, 72, 27, 42,
193, 240, 163, 146, 5, 52, 103, 86, 120, 73, 26, 43, 188, 141, 222, 239,
130, 179, 224, 209, 70, 119, 36, 21, 59, 10, 89, 104, 255, 206, 157, 172
]
def __init__(self, sck, data):
self.sck = Pin(sck)
self.data = Pin(data)
self.sck.init(Pin.OUT, Pin.PULL_UP)
self.data.init(Pin.OPEN_DRAIN, pull=None)
def temperature(self):
self.sck.init(Pin.OUT, Pin.PULL_UP)
self.data.init(Pin.OPEN_DRAIN, pull=None)
readout = self.__send_command(self.MEASURE_T)
return (readout - 3965) / 100.0
def humidity(self, temperature=25):
self.sck.init(Pin.OUT, Pin.PULL_UP)
self.data.init(Pin.OPEN_DRAIN, pull=None)
readout = self.__send_command(self.MEASURE_RH)
humidity = -2.0468 + 0.0367*readout - 1.5955e-6*readout**2
if temperature != 25:
humidity += (temperature - 25) * (0.01 + 8e-5 * readout)
return min(humidity, 100)
def read_register(self):
command = self.READ_STATUS_REGISTER
self.__command_start()
self.__write_byte(command)
self.__ack_bit(0)
# data should be low when ready to read
if self.data() == True:
raise self.AckException
readout = self.__read_byte()
crc = self.__read_byte()
computed_crc = self.__crc(command, readout, None)
if crc != computed_crc:
print('crc: {}, computed: {}'.format(crc, computed_crc))
raise self.CRCException
return readout
def __send_command(self, command):
self.__command_start()
self.__write_byte(command)
self.__ack_bit()
utime.sleep_ms(330)
# data should be low when ready to read
if self.data() == True:
raise self.AckException
msb = self.__read_byte()
lsb = self.__read_byte()
readout = (msb << 8) + lsb
crc = self.__read_byte()
computed_crc = self.__crc(command, msb, lsb)
if crc != computed_crc:
print('crc: {}, computed: {}'.format(crc, computed_crc))
raise self.CRCException
return readout
def __crc(self, command, msb, lsb):
crc = self.CRC_TABLE[command]
crc ^= msb
crc = self.CRC_TABLE[crc]
if lsb is not None:
crc ^= lsb
crc = self.CRC_TABLE[crc]
reversed_crc = 0
for pos in range(8):
bit = crc & 1<<pos != 0
if bit == 1:
reversed_crc |= 1<<7-pos
return reversed_crc
def __read_byte(self):
byte = 0
for pos in range(8, 0, -1):
bit = self.__read()
byte |= bit << pos-1
# print('{} {} {}'.format(pos-1, bit, byte))
self.data(False)
self.__ack_bit(0)
self.data(True)
return byte
def __read(self):
self.sck(False)
self.__noop()
self.sck(True)
self.__noop()
data = self.data()
self.sck(False)
self.__noop()
return data
def __write_byte(self, byte):
for pos in range(8, 0, -1):
bit = byte & 1<<pos-1 != 0
self.__write(bit)
def __write(self, value):
self.sck(False)
self.data(value)
self.__noop()
self.sck(True)
self.__noop()
self.sck(False)
self.__noop()
def __ack_bit(self, value=True):
self.sck(False)
self.__noop()
self.sck(True)
self.__noop()
self.sck(False)
self.__noop()
if self.data() != value:
raise self.AckException
def __command_start(self):
self.data(True)
self.sck(True)
self.__noop()
self.data(False)
self.__noop()
self.sck(False)
self.__noop()
self.sck(True)
self.__noop()
self.data(True)
self.__noop()
self.sck(False)
self.__noop()
def __noop(self):
utime.sleep_us(self.CLOCK_TIME_US)
Python - ePy-Lite_SHT11.py
"""
example code to read SHT1x using MicroPython
Reference: https://github.com/2black0/micropython-sht11
ePy-Lite SHT1x
-----------------
3V3 VCC
GND GND
P18_SDA0 SDA
P17_SCL0 SCL
"""
from machine import Pin
from machine import Switch #Get button KEY library
import utime
from sht11 import SHT11
# Start Function
if __name__ == '__main__':
KeyA = Switch('keya')
#pin sck and data used, change with yours
sht = SHT11(sck=Pin.board.P17, data=Pin.board.P16)
while True:
#read temperature and humidity
tempOut = sht.temperature()
humOut = sht.humidity()
#print temperature and humidity
print('Temperature:{:.2f}*C, Humidity:{:.2f}%'.format(tempOut,humOut))
if KeyA.value() == True: #Press A Key
break
utime.sleep_ms(1000)
執行結果
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