Mr. Turtle: A remotely controlled floating platform, equipped with sonar, lidar and temperature sensor.
Fig. 1: Waterproof temperature sensor (DS18B20). The long waterproof wire is led through a grouted whole in the box, where it is connected to the Raspberry Pi.
To measure water temperature we bought a waterproof temperature sensor produced py Sparkfun Electronics (Fig. 1). When Mr. Turtle floats on the water it drifts behind the platform and registers the surface water temperature.
To set up the temperature sensor on the Raspberry Pi we followed instructions on Raspberry Pi Tutorials. Additionally to the RasPi, wires and a breadboard/printed circuit board we need a 4.7 kΩ resistor.
With this Python 2 script the surface temperature is measured:
import RPi.GPIO as GPIO GPIO.setmode(GPIO.BOARD) GPIO.setup(12, GPIO.IN) def temp_messen(): # read 1-Wire Slave list file = open('/sys/bus/w1/devices/w1_bus_master1/w1_master_slaves') w1_slaves = file.readlines() file.close() # get current temperature for every 1-Wire Slave for line in w1_slaves: # extract 1-wire Slave w1_slave = line.split("\n") # read file 1-wire Slave file = open('/sys/bus/w1/devices/' + str(w1_slave) + '/w1_slave') filecontent = file.read() file.close() # read temperature values and convert them stringvalue = filecontent.split("\n").split(" ") temperature = float(stringvalue[2:]) / 1000 # print tamperature values print(str(w1_slave) + ': %6.2f C' % temperature) return(temperature) temp_messen()