Embedded Files
This project uses potentiometer to generate analog signal input for Arduino, and have some fun control of several LEDs when rotating the potentiometer, like levelling up/down the LEDs, seamlessly changing LEDs blinking speed. Goals:
Potentiometer what and how, use as voltage divider
Analog input in Arduino, analogRead(), use map() function to scale down the number range
Compound if-else logic practice,, and try out the switch-case flow controlling statement
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Efforts Estimation
Efforts Estimation
[ ] Simple: 30-60 minutes
[x] Moderate: 1-2 hours
[ ] Challenging: more than 2 hours
The estimation bases on average situation without unexpected troubleshooting, assuming that the student meets prerequisites. It only indicates rough time needed to complete this project, but not about technical difficulty, not covering discussion and sharing time.
Prerequisite
Prerequisite
One should have prior knowledge
Task 1: Wire Potentiometer and LEDs
Task 1: Wire Potentiometer and LEDs
Purpose: Get to know what is potentiometer and how to setup hardware connection
Basic Knowledge:
Basic Knowledge:
Right Results?
Right Results?
Exchange with your classmates to inspect correctness for each other
Task 2: Get Analog Input and Inspect Values in Serial
Task 2: Get Analog Input and Inspect Values in Serial
Purpose: Understand how to read analog input, and inspect the converted numeric values by serial printing
Recap Knowledge (Already Known):
Recap Knowledge (Already Known):
Core Knowledge (Must Know):
Core Knowledge (Must Know):
Questions:
Questions:
What are the min and max value in your test?
Have we missed pinMode(A0, INPUT)?
int pot_input;
void setup() {
Serial.begin(9600);
}
void loop() {
// Read analog input from pin A0
// resulted as integer ranged 0-1023
pot_input = analogRead(A0);
Serial.println(pot_input);
delay(300);
}
Task 3: Use Analog Input to Level Up/Down LEDs
Task 3: Use Analog Input to Level Up/Down LEDs
Purpose: Use analog input value, practice compound if-else logic
Core Knowledge (Must Know):
Core Knowledge (Must Know):
if-else
Challenges:
Challenges:
Fix the incomplete /* MISSING CODES HERE */ to make it working
This example solution is clear with the logic, but not very neat, can you figure out another solution still using if-else?
/* Please fix the MISSING CODES and debug working */
#define LED_GREEN 2
#define LED_YELLOW 3
#define LED_RED 4
int pot_input;
void setup() {
Serial.begin(9600);
pinMode(LED_GREEN, OUTPUT);
pinMode(LED_YELLOW, OUTPUT);
pinMode(LED_RED, OUTPUT);
}
void loop() {
// Read analog input from pin A0
// Resulted as integer ranged 0-1023
pot_input = analogRead(A0);
Serial.println(pot_input);
if (pot_input < 300) {
/* MISSING CODES HERE */
}
else if (pot_input >= 300 && pot_input < 600) {
/* MISSING CODES HERE */
}
else if (pot_input >= 600 && pot_input < 900) {
/* MISSING CODES HERE */
}
else if (pot_input >= 900) {
/* MISSING CODES HERE */
}
delay(300);
}
if (pot_input < 300) {
digitalWrite(LED_GREEN, LOW);
digitalWrite(LED_YELLOW, LOW);
digitalWrite(LED_RED, LOW);
}
else if (pot_input >= 300 && pot_input < 600) {
digitalWrite(LED_GREEN, HIGH);
digitalWrite(LED_YELLOW, LOW);
digitalWrite(LED_RED, LOW);
}
else if (pot_input >= 600 && pot_input < 900) {
digitalWrite(LED_GREEN, HIGH);
digitalWrite(LED_YELLOW, HIGH);
digitalWrite(LED_RED, LOW);
}
else if (pot_input >= 900) {
digitalWrite(LED_GREEN, HIGH);
digitalWrite(LED_YELLOW, HIGH);
digitalWrite(LED_RED, HIGH);
}
#define LED_GREEN 2
#define LED_YELLOW 3
#define LED_RED 4
int pot_input;
void setup() {
Serial.begin(9600);
pinMode(LED_GREEN, OUTPUT);
pinMode(LED_YELLOW, OUTPUT);
pinMode(LED_RED, OUTPUT);
}
void loop() {
// Read analog input from pin A0
// Resulted as integer ranged 0-1023
pot_input = analogRead(A0);
Serial.println(pot_input);
digitalWrite(LED_GREEN, LOW);
digitalWrite(LED_YELLOW, LOW);
digitalWrite(LED_RED, LOW);
if (pot_input >= 300) {
digitalWrite(LED_GREEN, HIGH);
}
if (pot_input >= 600) {
digitalWrite(LED_YELLOW, HIGH);
}
if (pot_input >= 900) {
digitalWrite(LED_RED, HIGH);
}
delay(300);
}
Task 4: Seamlessly Changing Blinking Speed by Scaled Analog Input
Task 4: Seamlessly Changing Blinking Speed by Scaled Analog Input
Purpose: Use map() function to scale down the number range, and try out the seamless changing blinking LED
Core Knowledge (Must Know):
Core Knowledge (Must Know):
Questions:
Questions:
What is the different experience comparing with the blinking speed changing using buttons?
#define LED_GREEN 2
#define LED_YELLOW 3
#define LED_RED 4
int pot_input;
int scaled_value;
void setup() {
Serial.begin(9600);
pinMode(LED_GREEN, OUTPUT);
pinMode(LED_YELLOW, OUTPUT);
pinMode(LED_RED, OUTPUT);
}
void loop() {
// Read analog input from pin A0
// Resulted as integer ranged 0-1023
pot_input = analogRead(A0);
// Scale down the range 0-1023 to 50-1000, which will be used as ms
scaled_value = map(pot_input, 0, 1023, 50, 1000);
Serial.print(pot_input);
Serial.print(",");
Serial.println(scaled_value);
digitalWrite(LED_GREEN, LOW);
digitalWrite(LED_YELLOW, LOW);
digitalWrite(LED_RED, LOW);
delay(scaled_value);
digitalWrite(LED_GREEN, HIGH);
digitalWrite(LED_YELLOW, HIGH);
digitalWrite(LED_RED, HIGH);
delay(scaled_value);
}
Task 5: Extended Learning and Exploring
Task 5: Extended Learning and Exploring
Purpose: Creative task for your ideas, as an optional challenge task
Option 1: More LEDs
Option 1: More LEDs
Add more LEDs, and find a better way to solve the need to level up/down the LEDs when rotating the potentiometer
Option 3: Try Scaled Analog Input and Switch-case to Solve Task 3
Option 3: Try Scaled Analog Input and Switch-case to Solve Task 3
Use map() function to scale down the number range, and try out the switch-case flow controlling statement for the same result as Task 3. This requires further knowledge, not necessary to understand every detail, but good as practice and inspiration
#define LED_GREEN 2
#define LED_YELLOW 3
#define LED_RED 4
int pot_input;
int scaled_value;
void setup() {
Serial.begin(9600);
pinMode(LED_GREEN, OUTPUT);
pinMode(LED_YELLOW, OUTPUT);
pinMode(LED_RED, OUTPUT);
}
void loop() {
// Read analog input from pin A0
// Resulted as integer ranged 0-1023
pot_input = analogRead(A0);
// Scale down the range 0-1023 to 0-3
scaled_value = map(pot_input, 0, 1023, 0, 3);
Serial.print(pot_input);
Serial.print(",");
Serial.println(scaled_value);
switch(scaled_value) {
case 0:
digitalWrite(LED_GREEN, LOW);
digitalWrite(LED_YELLOW, LOW);
digitalWrite(LED_RED, LOW);
break;
case 1:
digitalWrite(LED_GREEN, HIGH);
digitalWrite(LED_YELLOW, LOW);
digitalWrite(LED_RED, LOW);
break;
case 2:
digitalWrite(LED_GREEN, HIGH);
digitalWrite(LED_YELLOW, HIGH);
digitalWrite(LED_RED, LOW);
break;
case 3:
digitalWrite(LED_GREEN, HIGH);
digitalWrite(LED_YELLOW, HIGH);
digitalWrite(LED_RED, HIGH);
}
delay(300);
}
Knowledge test, reflection and discussion
Knowledge test, reflection and discussion
Purpose: Enhance basic knowledge understanding, reflect and summarize what we have learnt
Step 1: Knowledge Check
Step 1: Knowledge Check
What is potentiometer, what is the main purpose of using it in this project?
How do we get analog input? What are the values we get there in the program?
Tips: Review knowledge from here if needed
Step 2: Review and discuss
Step 2: Review and discuss
Follow the tutor to take 5-10 minutes to review the questions and answers, correct some possible misunderstood issues or faults
Reflect for findings and questions!
Reflect for findings and questions!
Take 1-2 minutes to explore anything on the tools and the making flow, with curiosity, no matter how much prior knowledge you have, you should make
At least 1 interesting finding
At least 1 curious question
Referred/Used By
Referred/Used By
Used by LP2519: Analog Input, 25w19
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