🏯 The Dojo

📋 Dojo Curriculum

Follow Sensei's curriculum in order for best results. Do NOT skip warm-up exercises!

🌡️ Temperature Sensors

📖 Lesson Overview

Temperature is the most fundamental physical quantity humans measure. From the ancient thermometers of Galileo to modern digital sensors, measuring heat has shaped human civilization. In this lesson, Sensei will introduce you to three paths of temperature sensing: analog IC sensors, digital sensors, and thermocouples.

🥷 Sensei's Recommended Sensors

⚡ Quick Code Example (Arduino — LM35)

// SensorSensei.net - LM35 Temperature Sensor
// "The first step on the temperature path..."

int sensorPin = A0;        // Connect LM35 output to A0
int sensorValue = 0;
float temperature = 0.0;

void setup() {
  Serial.begin(9600);
  Serial.println("Temperature Dojo - SensorSensei.net");
}

void loop() {
  sensorValue = analogRead(sensorPin);
  temperature = sensorValue * (5.0 / 1024.0 * 100.0);
  
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.println(" °C");
  
  delay(1000);  // Wait 1 second (patience, grasshopper!)
}
                

"The LM35 outputs 10mV per degree Celsius. Simple. Elegant. Beautiful." — SensorSensei

💧 Humidity Sensors

📖 Lesson Overview

Humidity affects everything from agriculture to electronics storage. Measuring moisture in the air requires special sensors that can detect water vapor molecules. Sensei will teach you about capacitive and resistive humidity sensing technologies.

🥷 Sensei's Recommended Sensors

⚡ Quick Code Example (Arduino — DHT11)

// SensorSensei.net - DHT11 Humidity Sensor
// "The air has moisture. We measure it."

#include 

#define DHTPIN 2     // Pin connected to DHT11 data
#define DHTTYPE DHT11  // Type of sensor

DHT dht(DHTPIN, DHTTYPE);

void setup() {
  Serial.begin(9600);
  dht.begin();
  Serial.println("Humidity Dojo - SensorSensei.net");
}

void loop() {
  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();
  
  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.print("%  Temp: ");
  Serial.print(temperature);
  Serial.println(" °C");
  
  delay(2000);  // DHT11 needs time (like all sensors, be patient!)
}
                

"Humidity sensor tip: Always wait the recommended delay between readings. Rushing gives bad data!" — SensorSensei

💡 Light Sensors

📖 Lesson Overview

Light sensing is one of the simplest and most rewarding sensor journeys. From the ancient gnomon to modern photometers, humans have always measured light. You will learn about photoresistors (LDRs), photodiodes, and digital light sensors.

🥷 Sensei's Recommended Sensors

⚡ Quick Code Example (Arduino — LDR)

// SensorSensei.net - LDR Light Sensor
// "Light becomes numbers. Magic, yes?"

int ldrPin = A0;    // LDR circuit connected to A0
int lightLevel = 0;

void setup() {
  Serial.begin(9600);
  Serial.println("Light Dojo - SensorSensei.net");
  Serial.println("Darkness is just low numbers.");
}

void loop() {
  lightLevel = analogRead(ldrPin);
  
  Serial.print("Light: ");
  Serial.print(lightLevel);
  Serial.print(" / 1024");
  
  if (lightLevel < 200) {
    Serial.print("  -> DARK!");
  } else if (lightLevel < 600) {
    Serial.print("  -> Normal");
  } else {
    Serial.print("  -> BRIGHT!");
  }
  
  Serial.println();
  delay(500);
}
                

"An LDR costs 10 cents and teaches more than most $100 sensors. Wisdom is simple." — SensorSensei

📳 Motion Sensors

📖 Lesson Overview

Motion sensors open the door to the exciting world of acceleration, rotation, and detection. From detecting if a box has been dropped to building a self-balancing robot, motion sensing is essential. You will explore accelerometers, gyroscopes, PIR sensors, and ultrasonic distance sensors.

🥷 Sensei's Recommended Sensors

💨 Gas Sensors

📖 Lesson Overview

Gas sensors give your projects the power of smell! Yes, you read that right. Your microcontroller will be able to detect smoke, CO2, propane, and volatile organic compounds. This is one of the most practical and life-saving sensor skills you can learn.

🥷 Sensei's Recommended Sensors

⚠️ SENSEI'S WARNING: Gas sensors require a WARMUP period! Readings during warmup are USELESS! ⚠️

"Never trust a gas sensor reading taken immediately after power-on. Even Sensei has been fooled by this." — SensorSensei, humbled