4C: Temperature

Make sure that your CoDrone Mini is paired before starting the lesson! If you forgot how to do this, make sure to review how to pair to Blockly here.

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. This is why most devices have a temperature sensor to make sure the components are not overheating.

For CoDrone Mini, the temperature sensor is mainly for calibrating the gyroscope sensor, which you will learn about in a future lesson. 

The CoDrone library has a method, get_drone_temp(), that returns the current drone temperature. By default, you will get the temperature in Celsius, but you can select Fahrenheit from a dropdown menu. 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’s not flying. Remember that this function returns the temperature of the drone, not the air around it!

Print the temperature in both Celsius and Fahrenheit.

Then, practice saving the temperature in both units using variables.

Now, print the temperature multiple times in a loop using either Celsius or Fahrenheit. How long do you think it will take to increase the temperature by one degree?

Tip: Include a sleep() block after each reading to make it easier to read the output.

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.

The drone will not warm up as much sitting on the ground as it does while flying. Write code to takeoff, hover, then land. Take the temperature before and after your flight to compare the values. Before you run your code, guess how many degrees the drone’s temperature will increase! Then, try hovering for more time by changing the seconds parameter.

Even though you can select the units of temperature, you can double-check by doing the temperature conversion yourself! Here are the formulas for converting Celsius to Fahrenheit and vice versa:

°C = (°F-32) x 5/9

°F = (°C x 9/5) + 32

First, read the temperature in Celsius and save it to a variable. Then, use the second equation to convert it into Fahrenheit. Save the answer in a new variable. Then, print out both values and check your answer with a calculator or with a converter online.

Now, do the opposite! Read the temperature in Fahrenheit and write the code to convert it to Celsius. Make sure to double-check by printing both values and doing the conversion yourself with a calculator.

In this activity, write a code that flies your drone up until the temperature gets too hot. When it does, make a flashing light pattern and land!

Start with a blinking green LED. Then, save the starting temperature in a variable. Then, create a max temp variable and set it to 3 degrees above the starting temperature. Throttle up with a blinking blue light while the temperature stays below the max temperature. When the drone temperature goes over the maximum temperature that you set, create a light pattern to signal a warning and land the drone immediately! Experiment with the threshold number or the temperature units.