CH24-D - Servo Map Angles

The 270 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.

Make sure the Orange Wire is closest to the number 13 for the Pin 13 column.

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).

If you've never used a micro:bit before you'll want to check out this guide: Bit Board V2 Setup and Use

We're going to load the following code for our Servo Map Angles program: https://makecode.microbit.org/_TWzAWxhFa...

We've written a function so we can get our 270˚ servo to function like a 180 servo.

Using the map function we can convert the angles so that calling the mapIt function with 0, 90 or 180 will move the servo to those actual positions.

How did we get the numbers 34 and 206? We started by taking 270-180 for 90, then divided in half for 45 and tried using 45 and 225 which has a 180 degree range...

When that didn't quite work we started adjusting the numbers until the angles for 90 and 180 were close to correct. It took a few tries to get right.

It may not be exact, and it may not work the same for every servo... but it's close enough for our needs.

Once the code is loaded it should start running immediately.

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.

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.

The servo will start at the 0 position, move approximately 90 degrees, and then move another 90 degrees, approximately.

These servos are never 100% accurate, but that is the nature of working with hobby servos. They are excellent for what they can do, with some limitations of course.

Follow along with our recorded Live Stream!

You can watch the full video of us walking through this project, along with explaining and exploring the code: https://youtube.com/live/T8jrPuhOp_g