first commit

examples/orangepi-sensors/ds18b20.py

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+#import sys
+import wiringpi
+from wiringpi import GPIO
+
+PIN = 6
+
+def oneWireReset(pin):
+	wiringpi.pinMode(pin, GPIO.OUTPUT)
+	wiringpi.digitalWrite(pin, GPIO.HIGH)
+	wiringpi.digitalWrite(pin, GPIO.LOW)
+	wiringpi.delayMicroseconds(500)
+	wiringpi.digitalWrite(pin, GPIO.HIGH)
+	wiringpi.delayMicroseconds(60)
+	wiringpi.pinMode(pin, GPIO.INPUT)
+	if not wiringpi.digitalRead(pin):
+		ack = 1
+	else:
+		ack = 0
+	wiringpi.delayMicroseconds(500)
+	return ack
+	
+def writeBit(pin, bit):
+	wiringpi.pinMode(pin, GPIO.OUTPUT)
+	wiringpi.digitalWrite(pin, GPIO.LOW)
+	wiringpi.delayMicroseconds(2)
+	wiringpi.digitalWrite(pin, bit)
+	wiringpi.delayMicroseconds(80)
+	wiringpi.digitalWrite(pin, GPIO.HIGH)
+	wiringpi.delayMicroseconds(1)
+
+def oneWireSendComm(pin, byte):
+	i = 0
+	while i < 8:
+		sta = byte & 0x01
+		writeBit(pin, sta)
+		byte >>= 1
+		i += 1
+
+def readBit(pin):
+	wiringpi.pinMode(pin, GPIO.OUTPUT)
+	wiringpi.digitalWrite(pin, GPIO.HIGH)
+	wiringpi.digitalWrite(pin, GPIO.LOW)
+	wiringpi.delayMicroseconds(2)
+	wiringpi.digitalWrite(pin, GPIO.HIGH)
+	
+	wiringpi.pinMode(pin, GPIO.INPUT)
+	wiringpi.delayMicroseconds(2)
+
+	tmp = wiringpi.digitalRead(pin)
+	wiringpi.delayMicroseconds(40)
+	return tmp
+
+def oneWireReceive(pin):
+	i = 0
+	k = 0
+	while i < 8:
+		j = readBit(pin)
+		k = (j << 7) | (k >> 1)
+		i += 1
+	k = k & 0x00FF
+	return k
+
+def tempchange(lsb, msb):
+	if (msb >= 0xF0):
+		msb = 255 - msb
+		lsb = 256 - lsb
+		tem = -(msb*16*16 + lsb)
+	else:
+		tem = (msb*16*16 + lsb)
+	temp = tem*0.0625
+	print("Current Temp: %.2f"%(temp))
+
+def main():
+	wiringpi.wiringPiSetup()
+	if oneWireReset(PIN):
+		oneWireSendComm(PIN, 0xcc)
+		oneWireSendComm(PIN, 0x44)
+	if oneWireReset(PIN):
+		oneWireSendComm(PIN, 0xcc)
+		oneWireSendComm(PIN, 0xbe)
+		lsb = oneWireReceive(PIN)
+		msb = oneWireReceive(PIN)
+	tempchange(lsb, msb)
+
+if __name__ == '__main__':
+	main()
+
+