UCLA BMES Build Team

Workshop 2 - Coding and ESP32

Activities:

Activity 1 - LED Time

Turn the LED on after 5 seconds using a conditional statement. (Note: Don’t use delay().)

Activity 2 - LED Flashing

Have the yellow LED turned on, then every 5 seconds turn off the yellow LED and have the red LED flash 10 times. (Note: Use delay())

Activity 3 - Storing Potentiometer Values

Store the past 5 values read from the potentiometer in an array, and print the array after every reading. To prevent output clutter, only read new values every 5 seconds (use delay())
The potentiometer is a voltage divider, and turning the knob changes the resistances R1 and R2. This allows you to change the output voltage, which is the middle pin. * The potentiometer has 3 pins: Power, Ground, and Signal.
- * Connect the power/Vcc pin to 3v3, the ground pin to ground, and the signal pin to an analog pin. Analog pins are labelled “ADC” in this diagram. * Use the analogRead instead of digitalRead to capture the voltage differences
- The array should be of ints, and should store the most recent value at index 0 at all times and the least recent value at index 4.
- Challenge activity: Also print the maximum and minimum value of the array every time a value is added.

Activity 4 - LED Button

LED lights up when the button is pressed and turns off when the button is not pressed
Use the code to achieve this rather than the circuit
- Wire the button and LED separately to the Arduino
- The button and LED should not be in the same circuit (separate power and ground)

Activity 5 - LED Switch

Have the LED turn on if off when the button is clicked and turn off if on when the button is clicked (toggle on/off)
Refer to Module 2 slides for the button circuit schematic

Activity 6 - LED Three Presses

Have an LED toggle on/off after three clicks of a button

Activity 7 - LED Blinking

Have two LEDs blink at different rates
Have one LED blink at a randomly created rate, and the other blink half as fast
Note that in order for the LEDs to blink independently of each other, you must use millis()

Activity 8 - Three LEDs

You have one button and three separate LEDs
When you hold the button, the first LED turns on
- If you are still holding the button after one second, the second LED also turns on
- If you are still holding the button after two seconds, the third LED also turns on
- If at any point you release the button, only the LEDs that have been turned on stay on
The next time you press the button, all the LEDs will turn off. Further button presses will continue the pattern.
- Hint: Don’t use delays [delay() will stall your code for the specified time]. Instead, think of a way to track time elapsed from the first button press using millis().

Activity 9 - Morse Code (Optional Challenge)

Write a program that lets you to input a word or sentence into the serial monitor and translate it to Morse code. Have an LED flash the Morse code.

Hint: Read in inputted string and cycle through it using loops
Optional: Print out Morse code in Serial Monitor and produce Morse code sound using piezo buzzer

Morse code array:

  String morse[26] = {".-", "-...", "-.-.", "-..", ".", "..-.", "--.", "....", "..",     // A-I
                      ".---", "-.-", ".-..", "--", "-.", "---", ".--.", "--.-", ".-.",   // J-R 
                      "...", "-", "..-", "...-", ".--", "-..-", "-.--", "--.."};         // S-Z

Serial read functions:

  if (Serial.available() > 0) // send data only when you receive data
  Serial.read() // reads incoming serial data
  Serial.readString() // reads characters from the serial buffer into a String

Solutions:

UCLA BMES Build Team