Maker.io main logo

Development Of The Christmas Bells

2020-12-17 | By Kitronik Maker

License: See Original Project

Courtesy of Kitronik

Hand bells playing Christmas tunes is a very traditional sound at that time of year. Of course, in the Kitronik development office, we like to add a technology twist. So, a plan was quickly hatched to make a microbit ring in the Christmas season.

A set of mini Rainbow Musical bells was ordered from Amazon and I began to produce a prototype, using the things we had to hand.

Development of The Christmas Bells:

Using technic lego a quick lever arm ringer was built. This proved that a microbit could drive a small servo sufficiently well to ring the bell.

lego_1

Initially, I experimented with 360-degree servos, where the servo arm dropped the bell by simply driving past. After a bit more experimentation I settled on 180-degree mini servos as they allowed for a more straightforward mechanism.

Mechanism_2

A laser cut equivalent bell ringer was made and tested, before making another 7, so all 8 bells could be rung. These were then arrayed on a baseplate, making a semicircle of bells with servos.

Ringer_3

Driving the Servos:

To move the servos, and hence ring the bells, there are a couple of choices. The Servo:Lite board can drive up to 3 servos, so a collaboration with 3 of these would be possible. To do this each microbit would need to know which bells it was responsible for, and then the 'master' micro:bit would broadcast the song on the radio channel, with each microbit driving the bells as they were called.

Servos_4

The other option is to use the 16 servo driver board. Here a single microbit can drive the 8 servos directly. I initially chose the 16 servo board option as it is more straightforward to create the software.

Board_5

The 16 Servo board has a set of custom blocks for the MakeCode environment. Find out how to add and use these blocks here. To ring the bell the micro:bit drives the servo to lift the arm off its stop, then reverses the servo to drop the arm quickly.

Blocks_6

The sudden impact causes the spring-loaded clapper to sound the bell. For my build, the servo needed driving from 80 degrees to 165 degrees to pick up the bell, then back to 80 degrees to drop it. For a step by step look at how the finished project was assembled, check out the resource we put out over Christmas here. Learn more about the author, learn more>>

©Kitronik Ltd – You may print this page & link to it but must not copy the page or part thereof without Kitronik's prior written consent.

制造商零件编号 DEV-14208
MICRO:BIT EVAL BRD
SparkFun Electronics
制造商零件编号 5623
SERVO:LITE BOARD FOR :MOVE MINI
Kitronik Ltd.
制造商零件编号 5612
KITRONIK 16 SERVO DRIVER BOARD F
Kitronik Ltd.
Add all DigiKey Parts to Cart
TechForum

Have questions or comments? Continue the conversation on TechForum, DigiKey's online community and technical resource.

Visit TechForum