1. Programming 2: The Arduino IDE & First Sketches
EGR 328
January 31, 2019

2. Overview The Arduino development environment Uploading sketches
The swap function
Using global variables
Using local variables with values passed in
Using Functions
Using Functions with Circuits
A first look at using switches
Photoresistor
Binary data – sending and receiving

3. Recap: Arduino Programming
/* Header comments should include the file/sketch name, a short description, your (author) name and the date */ void setup() { pinMode(13, OUTPUT); } void loop() digitalWrite(13, HIGH); delay(500); digitalWrite(13, LOW);
This setup() function
is executed only once

4. Recap: Arduino Programming
/* Header comments should include the file/sketch name, a short description, your (author) name and the date */ void setup() { pinMode(13, OUTPUT); } void loop() digitalWrite(13, HIGH); delay(500); digitalWrite(13, LOW);
The loop() function
is executed over,
and over, forever

5. Constant Declaration
// blink.pde with constant declared for LEDpin const int LEDpin = 13; void setup() { pinMode(LEDpin, OUTPUT); } void loop() digitalWrite(LEDpin, HIGH); delay(500); digitalWrite(LEDpin, LOW);

6. Constant Declaration
// blink.pde with compiler directive for LEDpin #define LEDpin 13 void setup() { pinMode(LEDpin, OUTPUT); } void loop() digitalWrite(LEDpin, HIGH); delay(500); digitalWrite(LEDpin, LOW);

7. The Arduino IDE

8. Uploading Sketches …

9. The Serial Monitor

10. Using the Serial Monitor for Strings
// Strings and Serial Monitor void setup() { Serial.begin(9600); Serial.println("Hello World!"); } void loop() {

11. Using the Serial Monitor for Strings
int counter = 1; void setup(){ Serial.begin(9600); } void loop(){ Serial.println("Hello World"); Serial.print("Counter = "); Serial.println(counter); delay(1000); counter++;

12. Using the Serial Monitor for Strings
// Strings and Serial Monitor char message[ ] = "Hello World”; void setup() { Serial.begin(9600); // Initialize serial monitor rate } void loop() Serial.println(message); delay(1000);

13. // Example 2: Turn on LED while button is pressed
const int LED = 13; // Connect the LED to pin 13
const int BUTTON = 7; // Connect the power lead for the
// pushbutton to pin 7
int val = 0; // store the state of the button
void setup() {
pinMode(LED, OUTPUT); // tell Arduino LED pin is an output
pinMode(BUTTON, INPUT); // tell Arduino BUTTON is an input }
void loop(){
val = digitalRead(BUTTON); // read voltage at the button
// check whether the input is HIGH (button pressed)
if (val == HIGH) {
digitalWrite(LED, HIGH); // turn LED ON (5V at output)
else {
digitalWrite(LED, LOW); // turn LED off (0V at output)

14. Other colors for other connections
What is the purpose
of the resistor?
Other colors for other connections
Color Code Wires
Black for Ground
Red for Power

15. Ohm’s Law
Voltage
Current
Resistance

16. pinMode()
Use for every pin using, to let Arduino know how to configure the pin to use with your electronics, your circuit
Define as either INPUT or OUTPUT
Use all caps
pinMode( outPin, OUTPUT);
pinMode( inPin, INPUT);

17. Examples from “Getting Started with Arduino”
Example 01: Simple LED Blink
Example 02: Push button control of LED
Example 03a: Keep LED on after button released
Example 03b: improved from 03a
Example 03c: improved from 03a and 03b

18. Compare this sketch to the following one: What is the
int x;
int y;
void setup() {
Serial.begin(9600); }
void loop() {
x = random(10);
y = random(10);
Serial.print("The value of x and y before swapping are: ");
Serial.print(x); Serial.print(","); Serial.println(y);
swap(); delay(1000);
Serial.print("The value of x and y after swapping are: ");
Serial.print(x); Serial.print(",");
Serial.println(y);Serial.println(); delay(1000);
void swap(){
int temp;
temp = x;
x = y;
y = temp;
Compare this sketch to the
following one: What is the
difference in the declaration
and use of the variables that
are swapped?

19. void swap(int &value1, int &value2); void setup() {
Serial.begin(9600); }
void loop() {
int x = random(10);
int y = random(10);
Serial.print("The value of x and y before swapping are: ");
Serial.print(x); Serial.print(","); Serial.println(y);
swap(x,y); delay (1000);
Serial.print("The value of x and y after swapping are: ");
Serial.print(x); Serial.print(","); Serial.println(y); Serial.println(); delay (1000);
void swap(int &value1, int &value2) {
int temp;
temp = value1;
value1 = value2;
value2 = temp;

20. Write a Program for this Function
int sensorPercent(int pin) { int percent; val = analogRead(pin); percent = map(val,0,1023,0,100); return percent; }

21. Note the use of the function, parameter passed and the return value.
void loop() { int count = blink3(250); Serial.print("The number of times ____________ "); Serial.println(count); } int blink3(int period) { int result = 0; int switchVal = HIGH; while(switchVal == HIGH){ digitalWrite(13,HIGH); delay(period); digitalWrite(13,LOW); result++; switchVal = digitalRead(inputPin); return result;
Note the use of the
function, parameter
passed and the
return value.

22. Arduino Libraries: Ex 1 Serial Communication Very Useful for Debugging
Serial.begin(9600)
Serial.print()
Serial.println()
Serial.available()

23. Photoresistor Circuit
Use a photoresistor, in a circuit and a sketch
For a sensor circuit…
That prints the sensor data value and...
The voltage level induced at the sensor input pin

24. Photoresistor Circuit
5 V
10 kΩ
photoresistor
analog input pin

25. Photoresistor Sketch
int sensorVal; const int sensorPin = 4; float voltage; const float input2volts = 5.0/1023.0; // 5V, 10 bits void setup() { Serial.begin(9600); } void loop() { sensorVal = analogRead( sensorPin ); voltage = float(sensorVal)*input2volts; Serial.print("SensorVal, Voltage = "); Serial.print(sensorVal); Serial.print(" "); Serial.println(voltage); delay(500);

26. Serial.write() function
Description from arduino.cc
Writes binary data to the serial port.
The data is sent as a byte or series of bytes
To send the characters representing the digits of a number use the .print() function instead.
Syntax
Serial.write(val)
Serial.write(str)
Serial.write(buf, len)
Parameters
val: a value to send as a single byte
str: a string to send as a series of bytes
buf: an array to send as a series of bytes
len: the length of the buffer
Returns
the number of bytes written, though reading that number is optional

27. Serial.print()
Prints data to the serial port as human-readable ASCII text (description from arduino.cc)
Numbers are printed using an ASCII character for each digit.
Bytes are sent as a single character.
Characters and strings are sent as is.
Serial.print(78) sends "78"
Serial.print("Hello world.") sends "Hello world."
Serial.print(78, BIN) sends " "
To send a single byte, use Serial.write()
This information is from

28. Integer Math – Beware!
// sketch to practice with the serial monitor; & math void setup() { Serial.begin(9600); // Setup communication int degC = 20; int degF; degF = degC * 9 / ; // integer math Serial.println(degF); // Print to monitor } void loop() {}

29. Floating Point Math
// sketch to practice with the serial monitor; & math void setup() { Serial.begin(9600); // Setup communication float degC = 20; float degF; degF = degC * 9.0 / ; // floating point math Serial.println(degF); // Print to monitor } void loop() {}

30. Your Programs Begin writing pseudocode for your first sensor programs
Comment everything clearly and concisely
What tasks, aka functions, will you use
What variables do you need in each
What is the input/output for each
Write the main() [loop() ] function

31. -- On Moodle --

32. (Good reference for C)
-- On Moodle –

33. -- On Moodle --