Page 10 of 16
Page 197
from machine import Pin,I2C
i2c0 = I2C(0,scl=Pin(18),sda=Pin(19),freq=100000)
buf = bytearray([0xE7])
i2c0.writeto( 0x40, buf, True)
read= i2c0.readfrom(0x40, 1, True)
print("User Register =",read)
Page 199
from machine import Pin,I2C
i2c0 = I2C(0,scl=Pin(18),sda=Pin(19),freq=100000)
buf = bytearray([0xE3])
i2c0.writeto( 0x40, buf, True)
read = i2c0.readfrom(0x40, 3, True)
msb = read[0]
lsb = read[1]
check = read[2]
print("msb lsb checksum =", msb, lsb, check)
Page 200
from machine import Pin,SoftI2C
i2c0 = SoftI2C(scl=Pin(18),sda=Pin(19),freq=100000)
buf = bytearray([0xE3])
i2c0.writeto( 0x40, buf, False)
read= i2c0.readfrom(0x40, 3, True)
msb = read[0]
lsb = read[1]
check = read[2]
print("msb lsb checksum =", msb, lsb, check)
Page 201
from machine import Pin,I2C
i2c0=I2C(0,scl=Pin(18),sda=Pin(19),freq=100000)
buf = bytearray([0xF3])
i2c0.writeto( 0x40, buf, True)
while True:
try:
read= i2c0.readfrom(0x40, 3, False)
break
except:
continue
msb = read[0]
lsb = read[1]
check = read[2]
print("msb lsb checksum =", msb, lsb, check)
Page 202
from machine import Pin,SoftI2C
from time import sleep_ms
i2c0 = SoftI2C(scl=Pin(18),sda=Pin(19),freq=100000)
buf = bytearray([0xF3])
i2c0.writeto( 0x40, buf, False)
while True:
sleep_ms(5)
try:
read = i2c0.readfrom(0x40, 3, True)
break
except:
continue
msb = read[0]
lsb = read[1]
check = read[2]
print("msb lsb checksum =", msb, lsb, check)
Page 206
from machine import Pin,I2C
def crcCheck(msb, lsb,check):
data32 = (msb << 16)|(lsb <<8)| check
divisor = 0x988000
for i in range(16):
if data32 & 1<<(23 - i):
data32 ^= divisor
divisor>>= 1
return data32
i2c0=I2C(0,scl=Pin(18),sda=Pin(19),freq=100000)
buf = bytearray([0xF3])
i2c0.writeto( 0x40, buf, False)
while True:
try:
read= i2c0.readfrom(0x40, 3, True)
break
except:
continue
msb = read[0]
lsb = read[1]
check = read[2]
print("msb lsb checksum =", msb, lsb, check)
data16= (msb << 8) | (lsb & 0xFC)
temp = (-46.85 +(175.72 * data16 /(1<<16)))
print("Temperature C ", temp)
print("Checksum=",crcCheck(msb,lsb,check))
buf = bytearray([0xF5])
i2c0.writeto( 0x40, buf, True)
read=bytearray(3)
while True:
try:
i2c0.readfrom_into(0x40,read, True)
break
except:
continue
msb = read[0]
lsb = read[1]
check = read[2]
print("msb lsb checksum =", msb, lsb, check)
data16 = (msb << 8) | (lsb & 0xFC)
hum = -6 + (125.0 * data16) / 65536
print("Humidity ", hum)
print("Checksum=",crcCheck(msb,lsb,check))
