Published April 29, 2019 © CC BY-NC-SA

Birds

A STEM interactive animated project for BBC micro:bit part of the Art-a-Tronic interactive art project.

IntermediateFull instructions provided10 hours1,987

Things used in this project

Hardware components

BBC micro:bit board

kitroniAll-in-one robotic control board for BBC micro:bit

SG90 Micro-servo motor

Software apps and online services

Microsoft MakeCode

Hand tools and fabrication machines

Laser cutter (generic)

Story

Birds is built with a simple electronic to create a nice scenery effect. To build the project I have followed two separate workflows: the building of the birds’ cage and the animatronics of the birds themselves, including electronics with micro:bit.

The inside of the cage - not visible - includes the moving parts laser-cut while the cage emulates a traditional chicken cage with a cardboard base (a black painted recycled box); the base of the cage is the container of the electronics and the moving engines.

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The support structure of the cage is built with 2×3 cm wooden splines joined on the top side by two M2 threaded bars to give robustness to the entire structure. Around the cage, I have fixed a chicken grid that gives good visibility to the interior with a touch of realism.

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The electronic assembly (no soldering is required) is based on the BBC micro:bit board and the All-in-one motor and servo controller by Kitronik (kitronik.co.uk), a board that can manage up to eight servos and four DC motors. For this project, I have used all the servo controllers available.

The laser cut parts can be done manually without difficulty with a couple of cutters, a scissor, and plywood saw but the precision of the laser makes the difference.

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The moving components are of two types; the birds, moved by five micro servos and the twitters, moved by continuous servos – very similar to a geared DC motor. The birds' motion is simple, through a 2 mm thick wire transmission. Using a software delay and a different starting position every one of the five subjects moves in a quite different way.

The creation of the twitters has been inspired by Rob Ives, a genial maker from the U.K. that creates ingenious paper mechanisms. I was searching by a lot of time a way to reproduce that choo-choo sound used in wall mount clocks very popular during the '60s and ‘70s decades. Finally, I met his site showcasing just what I was searching, easy to build from a single sheet of paper. First I made one of his models and it worked, then I studied the way to hack the design (released under a free Creative Commons license) adapting it to my needs. I made a set of three different tweeters moved by the continuous servos with a rotating cam mechanism.

The complete Birds cage is one of the interactive machines shown at the Art-a-Tronic exhibition in Gent, from April, 5 until May 31.

Code

Birds.js

let increment = 0
let maxBird: number[] = []
let trigAcceleration = 0
let birdDirection: number[] = []
let stepBirdAngle: number[] = []
let birdPosition: number[] = []
let BirdMoveDelay = 0
function moveBirds() {
    Kitronik_Robotics_Board.servoWrite(Kitronik_Robotics_Board.Servos.Servo4, birdPosition[0])
    Kitronik_Robotics_Board.servoWrite(Kitronik_Robotics_Board.Servos.Servo5, birdPosition[1])
    Kitronik_Robotics_Board.servoWrite(Kitronik_Robotics_Board.Servos.Servo6, birdPosition[2])
    Kitronik_Robotics_Board.servoWrite(Kitronik_Robotics_Board.Servos.Servo7, birdPosition[3])
    Kitronik_Robotics_Board.servoWrite(Kitronik_Robotics_Board.Servos.Servo8, birdPosition[4])
    for (let index = 0; index <= 4; index++) {
        increment = stepBirdAngle[index] * birdDirection[index]
        birdPosition[index] = birdPosition[index] + increment
        if (birdPosition[index] < 0) {
            birdDirection[index] = -1 * birdDirection[index]
            birdPosition[index] = 0
        }
        if (birdPosition[index] > maxBird[index]) {
            birdDirection[index] = -1 * birdDirection[index]
            birdPosition[index] = maxBird[index]
        }
        basic.pause(BirdMoveDelay)
    }
}
function startTwitters2() {
    Kitronik_Robotics_Board.servoWrite(Kitronik_Robotics_Board.Servos.Servo1, 20)
    Kitronik_Robotics_Board.servoWrite(Kitronik_Robotics_Board.Servos.Servo2, 170)
    Kitronik_Robotics_Board.servoWrite(Kitronik_Robotics_Board.Servos.Servo3, 160)
}
Kitronik_Robotics_Board.allOff()
BirdMoveDelay = 5
stepBirdAngle = [1, 3, 2, 2, 5]
birdDirection = [-1, -1, -1, -1, -1]
birdPosition = [45, 70, 80, 60, 90]
maxBird = [80, 70, 90, 60, 90]
trigAcceleration = 1018
basic.forever(function () {
    led.enable(true)
    basic.showIcon(IconNames.Duck)
    if (input.acceleration(Dimension.Strength) <= trigAcceleration) {
        startTwitters2()
        for (let i = 0; i < 500; i++) {
            moveBirds()
        }
        Kitronik_Robotics_Board.allOff()
    }
    led.enable(false)
})

Credits

Enrico Miglino

4 projects • 20 followers

Software and hardware developer, designer and photographer, maker and (maybe) inventor. I work on Windows, iOS, Android, Linux, MCUs

Birds

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Custom parts and enclosures

SVG Files

Code

Birds.js

Credits

Enrico Miglino

Comments

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Birds

Birds

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Custom parts and enclosures

SVG Files

Code

Birds.js

Credits

Enrico Miglino

Comments

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