Arduino 102

Creative Technology Residency

Last Class

• Arduino hardware overview, sensors
• Blinking an LED from last class
• Basics of Arduino programming
• Discussion of variables, inbuilt Arduino functions, Serial communication
• Digital vs Analog vs PWM pins
• Conditional statements
• Component exploration: buttons, RGB control, potentiometers, joysticks

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• How did the practice exercises go?

Class Outline

• Functions
• Loops
• Addressable LEDs
• Installing and using libraries
• Servo motors
• Learning to use new components independently/building projects: automated plant watering pump
• Free flex time: explore components and code with guided support, start discussing and designing month 2 build project

Functions

• A small “chunk” of code
• Cookbook analogy
• Functions contained within curly brackets: { }
• Example of a function: RGB LED
• Local vs global variables

For Loops

Block of code that repeats instruction over a range of values

Example: fading an LED, accelerating a motor

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for (initialization; condition; increment) {

// executable code

}

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Example: fading RGB from OFF to red

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for(int r = 0; r <= 255; r ++){

writeRGB(r, 0, 0);

}

Nested For Loops

We can put for() loops inside each other

Useful for iterating over multiple varibales/counters

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for (initialization; condition; increment) {

// executable code

for (initialization; condition; increment) {

// executable code

}

}

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Example: RGB transitions

Smooth Colour Wheel Transitions

A more elegant approach to RGB transitions is the use of a colour wheel

Need to fade in on one colour while fading out on another

While Loops

A loop that executes continuously until the conditional state turns FALSE

Danger of getting stuck in an infinite loop

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LED Problems of Scale

Solution? NeoPixels!

• Addressable LEDs
• Only need 3 wires to control hundreds or even thousands of LEDs!
• “NeoPixels” is technically a brand name. “WS2812B” is the true LED name.’
• Come in densities of 30, 60, and 144 LEDs per meter

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How to Wire NeoPixels

Installing Libraries & Programming NeoPixels

• Sketch > Include Library > Manage Libraries > Search “Adafruit NeoPixel”
• Install “Adafruit NeoPixel”
• File > Examples > Adafruit NeoPixel > strandtest
• Update variables “LED_pin” and “LED_count” (line 20 and 23, respectively)
• Upload program

Soldering LED strips

• Pre tin wires and LED pads

What are libraries

Provide extended features specific to individual modules beyond what the standard Arduino environment provides.

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An example of a pre-installed library is the Servo library

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What is a servo?

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A Simpler NeoPixel Program

• Turn a single LED to one colour
• Programming languages start indexes at “0”

strip.setPixelColor(index, R, G, B);

Example code:

strip.setPixelColor(4, 255, 0, 0);

strip.setPixelColor(7, 255, 0, 255);

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index 4

index 7

Another NeoPixel Program

• Turn all LEDs to one colour
• Programming languages start indexes at “0”

strip.fill(colour, first_index, led_count);

Example code:

strip.fill(red, 3, 6);

strip.fill(green, 9, 3);

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index 0

index 3

turn 6 LEDs red, then stop

turn 3 LEDs green, then stop

index 9

Alternative NeoPixel Form Factors

• Rings
• Flexible Arrays
• Wearables
• Flexible Neon Strips
• Fairy Lights

What is a Servo?

• DC Motor
• Potentiometer
• Constrained rotation [0, 180] degrees
• Investigate Servo library, open example files

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map() function

map() function is used for rescaling a range of values

• map(value, fromLow, fromHigh, toLow, toHigh)

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Exercise:

• Measure input from a potentiometer, rescale measurement using map() function to a servo angle.
• Hint: range of potentiometer readings is 0 -> 1023

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Exercise: Create a project from the ground up

When starting a new project you may need to use a component you’ve never seen before? How do you learn how to use it?

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• Look for guides/tutorials/documentation online, ask ChatGPT
• How is it wired to the Arduino?
• What does the software look like? Does it require additional software libraries?
• Can you make a unique modification to the tutorial code?

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Building an automated plant watering system:

• What are we looking to achieve?
• What sensors, actuators, and displays are required for this?
• Break project down into subsystems and validate individually before integration

Materials

• DC Motor
• Motor Driver (product link)
• OLED Display
• Protoboard/Breadboard
• Arduino Nano
• Jumper wires
• 5V power supply
• Barrel jack adapter

Open Discussion: Planning Month 2 Project(s)

• Personal ideas/designs
• Looking online for inspiration and project build guides
• What materials are required
• Overall design process and steps
• Making an timeline

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Exercises to Practice

• Independent fabrication of water pump system
• Sunday support hours
• Research and plan project builds for next month