Pre-Lecture Prep and Pre-Quiz

No pre-quiz for this lecture!

Announcements

• Homework 4 is due today.
• The midterm exam is next Thursday. We will have a review session next Tuesday.
• Office hours and wizard sessions:
  • Delano: Wednesdays at 3pm-5pm EDT (same zoom link as lecture), or by appointment
  • Cheever: check his schedule
  • Ruether: by appointment Wednesdays 10am-12pm, Thursdays 3pm-5pm EDT (link)
  • Wizard sessions: Sunday 1-3pm EDT, Monday 7-9pm EDT (zoom link on moodle)

Learning Objectives and Outcomes

In this lecture, you will...

• Listen to a short lecture about how to receive inputs from the serial terminal
• Listen to a short lecture defining the terms blocking and non-blocking
• Work in small groups to write a series of sketches to receive inputs from the Serial terminal in either a blocking or non-blocking manner

By the end of this lecture, you should be able to...

• Explain the difference between blocking and non-blocking operations
• Use if statements and while loops to implement blocking or non-blocking versions of code

Receiving Inputs from the Serial Terminal

The serial terminal can be used to receive information as well as write it:

// include CircuitPlayground library so we can use CircuitPlayground.
#include <Adafruit_CircuitPlayground.h>

char recChar; // received character

void setup() {
  CircuitPlayground.begin();
  CircuitPlayground.clearPixels();

  Serial.begin(9600);
  while(!Serial);
  
}

void loop (){
  
	// if number of bytes available is greater than zero
	// Serial.available() returns the number of characters
	// received by the Serial terminal
	// while (Serial.available()) is shorthand for:
	// while (Serial.available() > 0)
  while (Serial.available() > 0){

    // save and print received character
		// Serial.read() times out (default is 1s)
		// therefore we usually want to read only when Serial.available() > 0
    recChar = Serial.read(); // puts the character into variable

    Serial.print(recChar);
  }
}

We use a char instead of a byte so that the serial terminal prints out the character code we want, rather than the ASCII value!