Temperature

You have heard of Fahrenheit, Celsius, or Kelvin. These units express how hot or cold something is. You might prefer when it’s warm outside but others prefer the cold. However, we are not suited for all temperatures!

There are some species of animals that can survive extreme temperatures that humans would find unbearable! Polar bears, penguins, and beluga whales are some animal species that can survive in freezing temperatures. On the other hand, desert tortoises, kangaroo rats, and camels can withstand very high temperatures. In general, species have an optimal temperature range where they can best survive.

Just like animals, electrical components also have their limits. The operating temperature is the temperature at which an electrical or mechanical component can function. In this lesson, you’ll conduct an experiment to find out how hot the drone gets while flying and find its maximum operating temperature.

The CoDrone library has a method, get_drone_temp(), that returns the current drone temperature in Celsius. You may be used to Fahrenheit, so don’t be alarmed if the output does not make sense. Later, you’ll write a function to convert the degrees in Celsius to degrees in Fahrenheit.

For the first activity, you will practice getting the drone temperature while it is not flying. Remember that this function returns the temperature of the drone, not the air around it!

Import your libraries and set up pairing to the drone. Using a while loop, call the function to get the drone temperature, and then print the value. Run the code for about 10 seconds after pairing. Use a calculator or spreadsheet to find out what the average temperature is.

timer = time.process_time()
while timer < 10:
    temp = drone.get_drone_temp()
    print(temp)
    timer = time.process_time()

Even though the drone is not flying, you probably noticed that it’s pretty warm! From the last step, you probably found that the average temperature was between 30-33 degrees Celsius. That’s about 86-91 degrees Fahrenheit! What is happening?

Remember from the battery lesson that the battery is supplying energy to turn on the drone. Not all of the energy makes it back to the battery. Some of it is converted to heat, which is what you are observing.

Think about this another way: even when you are not moving, your internal body temperature is pretty hot — about 98.6 degrees Fahrenheit. That is because your muscles, metabolism, and even digestive system are working hard and producing heat along the way.

How warm do you think the drone gets while it’s flying? In this experiment, you will determine the maximum operating temperature. In order to keep the drone from flying away from you, you are going to carefully hold the drone in your hand while you throttle upward forever. Make sure you have a fully charged battery.

After a few minutes, you will notice a point where CoDrone will start turning on and off. Why do you think this is?

import CoDrone
import time
drone = CoDrone.CoDrone()
drone = drone.pair(drone.Nearest)
drone.takeoff()
while True:
    drone.move(0, 0, 0, 100)
    temp = drone.get_drone_temp()
    print(temp)

Copy and paste all of the data from your output into a spreadsheet like Google Sheets.

Your graph should look something like this. A red line of best fit can help you predict the temperature of the drone after a number of flight seconds. The graph also shows that at a certain temperature, CoDrone has reached its maximum limit. You can also see the maximum temperature oscillating. The dips in temperature are the moments where CoDrone turned off. What kind of graph do you think it is? Linear? Exponential? Or logarithmic?