Introduction
Connect a 360˚ Servo to a Bit Board and control it with a Potentiometer and code.
We'll explore code to control the movement of a continuous rotation (360 degree) servo motor using a potentiometer.
Video Overview
Featured Document
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The 360 Degree Servo Motor has a 3-wire connector on the end that can plug directly into the pins on the back of the Bit Board.
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Make sure the Orange Wire is closest to the number 13 for the Pin 13 column.
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Then the Brown Wire should be closest to the micro:bit (in the - row) and the Red Wire will be in the middle (the +5v row).
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We'll need to connect one side of the Potentiometer to Ground (GND) and the other side to 3.3v
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We will then connect the center of the Potentiometer to Pin 0. (Note that Pin 0 is an analog pin, which we'll need for the Potentiometer.)
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The other analog pins are 1, 2, 3, 4, and 10. See this chart for a pinout diagram: https://makecode.microbit.org/device/pin...
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You'll notice the Ground on the Bit Board is color coded White.
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The 3.3v hole on the Bit Board is labeled and is actually two holes right next to each other on the Bit Board. (There is a small line showing the connection between them.)
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If you've never used a micro:bit before you'll want to check out this guide: Bit Board V2 Setup and Use
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We're going to load the following code for our 360 Servo Potentiometer Start Stop program: https://makecode.microbit.org/_Eq5MLJ0yY...
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We'll run an analog read pin on Pin 0 and assign that to a variable named potVal.
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We'll check if the potVal is 595 or lower or if potVal is greater than 595. We will set some values (and use different math) depending which if/else is true.
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We then spin the motor for the amount of time set in runTime, then stop the motor for the amount of time in stopTime.
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Once the code is loaded it should start running immediately.
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You can power the micro:bit via the USB cable you used to load the code, but now that we are using servos we recommend using a battery pack plugged into the Bit Board.
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The Blue Pins on the Bit Board provide extra power (5 volts instead of 3 volts) by boosting the voltage coming from the battery pack. This helps improve servo performance, especially with multiple servos.
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Turn the Potentiometer knob and watch how the motor reacts.
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Try to compare the motor action to the code and see if it makes sense!
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Follow along with our recorded Live Stream!
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You can watch the full video of us walking through this project, along with explaining and exploring the code: https://youtube.com/live/1H9jjAUFHAI
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