5. Stall detection

You must first complete 4. Alignment before viewing this Lesson

3.1. What is Stall Detection and Why Use It?

Stall detection is a program that stops your motor when the motor gets stuck.

If you are an FLL team, you usually have to grab your robot and get a touch penalty if your robot stalls.
When you use stall detection techniques, your robot will move on to the next program block.

For example, if a robot needs to move the arm down before it says “Good job”. However, if the motor stalls, it will never say “Good job.”

3.2. Move Degrees vs. Move Seconds

In our lesson on Move Blocks (Intermediate), we said that if you use Move Degrees, your motor may get stuck.
Move Seconds helps avoid stalls, but is not as accurate.

Are these the only choices?
How can you use Move Degrees and prevent stalls?

Note: In this lesson, you will need an arm connected to a motor!

Step 1: Move Until Stall

Step 2A: Move Degrees + Stall Detection

Step 2B: Alternate Move Degrees + Stall Detection

What is a stall?
Ans. When you motor gets stuck and the program never moves on to the next block.
Why is stall detection useful?
Ans. When the robot stalls, it gives up on that block of code and moves on to the next block of code

Back to: Module 4. Robotics Coding and Driving