Introduction to Sensors in Robotics

What You’ll Learn 📚

• Core concepts of sensors in robotics
• Key terminology with friendly definitions
• Simple to complex examples with code
• Common questions and troubleshooting tips

Introduction to Sensors

Sensors are like the senses of a robot. Just as humans use eyes to see and ears to hear, robots use sensors to perceive their environment. Sensors gather data from the surroundings, which the robot can then use to make decisions.

Key Terminology

• Sensor: A device that detects and responds to some type of input from the physical environment.
• Actuator: A component of a machine that is responsible for moving or controlling a mechanism or system.
• Microcontroller: A compact integrated circuit designed to govern a specific operation in an embedded system.

Getting Started with a Simple Example

# Python code for a light sensor example
import RPi.GPIO as GPIO
import time

# Set up the GPIO pin
GPIO.setmode(GPIO.BCM)
LIGHT_PIN = 18
GPIO.setup(LIGHT_PIN, GPIO.IN)

try:
    while True:
        if GPIO.input(LIGHT_PIN):
            print('Light detected!')
        else:
            print('No light detected.')
        time.sleep(1)
except KeyboardInterrupt:
    GPIO.cleanup()

Progressively Complex Examples

# Python code for an ultrasonic sensor example
import RPi.GPIO as GPIO
import time

TRIG = 23
ECHO = 24

GPIO.setmode(GPIO.BCM)
GPIO.setup(TRIG, GPIO.OUT)
GPIO.setup(ECHO, GPIO.IN)

try:
    while True:
        GPIO.output(TRIG, False)
        time.sleep(2)

        GPIO.output(TRIG, True)
        time.sleep(0.00001)
        GPIO.output(TRIG, False)

        while GPIO.input(ECHO) == 0:
            pulse_start = time.time()

        while GPIO.input(ECHO) == 1:
            pulse_end = time.time()

        pulse_duration = pulse_end - pulse_start
        distance = pulse_duration * 17150
        distance = round(distance, 2)

        print('Distance:', distance, 'cm')

except KeyboardInterrupt:
    GPIO.cleanup()

Common Questions and Troubleshooting

1. Why isn’t my sensor detecting anything?

   Check your connections and ensure the sensor is properly powered.

2. What if the readings are inconsistent?

   Try adding a delay between readings or check for interference from other devices.

3. How do I know which sensor to use?

   Consider the environment and the type of data you need. Light sensors for brightness, ultrasonic for distance, etc.

💡 Remember, practice makes perfect. Don’t worry if this seems complex at first. Keep experimenting and learning!

Practice Exercises

• Try using a temperature sensor to read and display temperature data.
• Integrate multiple sensors and create a simple robot that can avoid obstacles.

For more information, check out the Arduino Guide and Raspberry Pi Documentation.