pxt-calliope/docs/projects/milk-carton-robot/code.md
2019-09-11 10:54:24 -07:00

1.5 KiB

Code

@description code to make the Milk Carton Robot alive

~avatar avatar

Add code to make the Milk Carton Robot move.

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Duration: ~15 minutes

Step 1: wire up the servo

Follow the instructions in servo 101 manual to connect the servo to the @boardname@.

https://youtu.be/m-HS8OyS0pw

Step 2: code light sensor

Code the lightsensor on the @boardname@ to control the servo.

basic.forever(() => {
    led.plotBarGraph(
        input.lightLevel(),
        0
    )
    pins.servoWritePin(AnalogPin.P0, input.lightLevel())
})

https://youtu.be/Ah4fEbJtklU

It works but your servo might be trying to move too much. Let's calibrate it.

Step 3: calibrate the servo

Download the servo calibration program to determine the opening and closing angles of the servo for your robot.

https://youtu.be/lZxWC82HDn0

We are going to map the light level range, [0, 255] to the angle range, [closed, opened] using pins.map.

let angle = 0
let closed = 0
let opened = 0
basic.forever(() => {
    led.plotBarGraph(
        input.lightLevel(),
        0
    )
    angle = pins.map(
        input.lightLevel(),
        0,
        255,
        opened,
        closed
    )
    pins.servoWritePin(AnalogPin.P0, angle)
})
// TODO: use the angle found at calibration!
opened = 95
// TODO: use the angle found at calibration!
closed = 175

~button /projects/milk-carton-robot/connect

NEXT: Connect

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