Programming in Arduino

1. Programming in Arduino Pre Pres. Notes Casperelectronics Photos from workshop? Materials:Arduino Board

2. Arduino.cc has the IDE programming software for free download

3. Arduino Sketch Arduino files are called “sketches”. Arduino sketches must be compiled in the IDE before being downloaded to the Arduino board.

4. Program Structure • Two required functions in an Arduino sketch, setup() and loop(). • setup() The function is called when your program starts. Use it to initialize your variables, pin modes, start using libraries, etc. The setup function will only run once, after each powerup or reset of the Arduino board. • Loop() After creating a setup() function, which initializes and sets the initial values, the loop() function does precisely what its name suggests, and loops consecutively, allowing your program to change and respond. Use it to actively control the Arduino board.

5. What does “void” mean • The void keyword is used only in function declarations. It indicates that the function is expected to return no information to the function from which it was called.

6. Libraries • Extend the capabilities of Arduino IDE • Offer simpiler ways of controlling hardware they are written for. • Advanced. will talk about later.

7. Variables • Let you store a value. • Must declare variables and tell computer what kind of value to expect. Int- number between -32,768 to 32,767 Byte- 0 -255 char- type character and more……

8. Int variable int- an integer is a whole number (1,2,3,25) • are your primary datatype for number storage, and store a 2 byte value (take 2 bytes of memory). This yields a range of -32,768 to 32,767 example: int ledpin = 13; // sets the variable named ledpin to 13

9. Char variable char- A data type that takes up 1 byte of memory that stores a character value. Both of these are equivalent and refer to the letter A: char myChar = 'A'; char myChar = 65; in ASCII

11. Byte variable • Byte- an integer between 0 and 255 (byte uses less memory, only 1 byte) • Made up of 8 bits. Example in binary: 00000001, 00000011

12. Binary Numbering (how computers count) If computers only know 1 and 0 how do they form complex operations? • 128 64 32 16 8 4 2 1 • 00000001 = 1 • 00000010 = 2 • 00000011= 3 • 00000100 = 4

13. Programming- Functions • Segmenting code into functions allows a programmer to create modular pieces of code that perform a defined task and then return to the area of code from which the function was "called". • Existing Functions- commands Arduino automatically understands • Custom Functions -The typical case for creating a function is when one needs to perform the same action multiple times in a program.

14. Example Functions:pinMode(), digitalWrite(), and delay() • The pinMode() function configures a pin as either an input or an output. pinMode(ledPin, OUTPUT); // sets the digital pin as output • The digitalWrite() function outputs a value HIGH or LOW on a pin. For example, the line: digitalWrite(ledPin, HIGH); //sets pin high • The delay() causes the Arduino to wait for the specified number of milliseconds before continuing on to the next line. There are 1000 milliseconds in a second, so the line: delay(1000); // creates a delay of one second.

15. Pseudocode: Blink an Led English: I want an led to blink, on for a second and off for a second forever. Pseudocode: Turn led on wait Turn led off Loop again

16. Pseudocode Translation void loop() // run over and over again { digitalWrite(ledPin, HIGH); // sets the LED on delay(1000); // waits for a second digitalWrite(ledPin, LOW); // sets the LED off delay(1000); // waits for a second }

17. Blink an Led(w/o comments) int ledPin = 13; void setup() { pinMode(ledPin, OUTPUT); } void loop() { digitalWrite(ledPin, HIGH); delay(1000); digitalWrite(ledPin, LOW); delay(1000); }

18. Blink an Led int ledPin = 13; // LED connected to digital pin 13 void setup() // run once, when the sketch starts { pinMode(ledPin, OUTPUT); // sets the digital pin as output } void loop() // run over and over again { digitalWrite(ledPin, HIGH); // sets the LED on delay(1000); // waits for a second digitalWrite(ledPin, LOW); // sets the LED off delay(1000); // waits for a second }

19. Demo Programming board

20. HW : Bring in a video or webpage link that is related to Physical Computing that you think is interesting and be prepared to talk about it in class.