Java with Raspberry Pi

Stephen Chin (@steveonjava)Java Community ManagerJavaOne Conference Chair

Java ScaleRaspberry Pi Coffee

Fuglen Coffee

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The Coffeeshop Roast Works

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About Life Coffee

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Bridge Coffee and Ice Cream

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Bridge Coffee and Ice Cream

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Latte at Bridge

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Peace Coffee Roasters

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Aeropress at Peace

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Little Nap Coffee Stand

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Espresso from Little Nap

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AeroPress

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Porlex Grinder

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Finding a USB Scalepublic static UsbScaleTest findScale() throws UsbException {

UsbServices services = UsbHostManager.getUsbServices();

UsbHub rootHub = services.getRootUsbHub();

// Dymo M10 Scale:

UsbDevice device = findDevice(rootHub, (short) 0x0922, (short) 0x8003);

// Dymo M25 Scale:

if (device == null) {

device = findDevice(rootHub, (short) 0x0922, (short) 0x8004);

}

return new UsbScaleTest(device);

}

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Printing out Weightpublic void dataEventOccurred(UsbPipeDataEvent upde) {

boolean empty = data[1] == 2;

boolean overweight = data[1] == 6;

boolean negative = data[1] == 5;

boolean grams = data[2] == 2;

int scalingFactor = data[3];

int weight = (data[4] & 0xFF) + (data[5] << 8);

System.out.println(String.format("Weight = %,.1f%s",

scaleWeight(weight, scalingFactor),

grams ? "g" : "oz"));

}

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Driving Test

https://www.flickr.com/photos/davidyuweb/1352312273

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Up-Up-Down-Down-Left-Right-Left-Right B, A, Start

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Meet Mr. Grabby

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https://www.flickr.com/photos/pasukaru76/8278458818/https://www.flickr.com/photos/fallentomato/5656700432/

+ =

Meet Mr. Grabby

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Mr. Grabby's Back

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Controller

Grabber

Controller

• Raspberry Pi

• Cooking Hacks Shield

• MakeBlocks ME Base Shield

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Mr. Grabby's Belly

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Line Follower

Batteries

DC Motors

How Line Followers Work

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• Infrared LED

– Bounced light off the ground

• Infrared Luminosity Sensor

– Detects reflected light

Getting GPIO

gpio = GpioFactory.getInstance();

lineFollowA = gpio.provisionDigitalInputPin(RaspiPin.GPIO_13, "LineFollowA");

lineFollowB = gpio.provisionDigitalInputPin(RaspiPin.GPIO_14, "LineFollowA");

startGPIO();

boolean leftSensor = lineFollowA.getState().isHigh();

boolean rightSensor = lineFollowB.getState().isHigh();

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Line Following Algorithm

if (leftSensor && rightSensor) { //we are lost

doDrive(lineLocation);

} else if (!leftSensor && !rightSensor) { //on the line

lineLocation = Drive.forward; doDrive(Drive.forward);

} else if (!leftSensor && rightSensor) { //off the right

lineLocation = Drive.left; doDrive(Drive.forward);

} else if (leftSensor && !rightSensor) { //off the left

lineLocation = Drive.right; doDrive(Drive.forward);

}

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Make your own Mr. Grabby

• MakeBlock Advanced Robotics Kit

• MakeBlock ME Base Shield

• Cooking Hacks Shield

• USB Battery (1A)

• Code here:

https://github.com/steveonjava/LineFollower

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Ultimaker 2

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Java Constructive Geometry (JCSG / JFXScad)

• Create geometries from pure Java code

• Visualize with a JavaFX user interface

• Generate STL files for 3D printing

• Project sites:

https://github.com/miho/JCSG

https://github.com/miho/JFXScad

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JJUG Exclusive Pepper Workshop

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Stephen Chintweet: @steveonjavablog: http://steveonjava.com

nighthacking.com

Real Geeks

Live Hacking

NightHacking Tour

Safe Harbor Statement

The preceding is intended to outline our general product direction. It is intended for information purposes only, and may not be incorporated into any contract. It is not a commitment to deliver any material, code, or functionality, and should not be relied upon in making purchasing decisions. The development, release, and timing of any features or functionality described for Oracle’s products remains at the sole discretion of Oracle.

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