Integrating External Sensors with SPIKE Prime: Expand Your Robot's Capabilities

Integrating External Sensors with SPIKE Prime: Expand Your Robot's Capabilities

The SPIKE Prime hub is a powerful tool for learning about robotics and programming, but its built-in sensors have limitations. Integrating external sensors allows you to overcome these limitations and create robots that can perform more complex tasks, gather more detailed data, and react to their environment in more nuanced ways. This is crucial for success in robotics competitions like FIRST LEGO League (FLL) and World Robot Olympiad (WRO), and for any project that requires precise environmental sensing.

This guide will walk you through the process of connecting and programming various external sensors with your SPIKE Prime. We'll cover the essential safety considerations, wiring instructions, and example Python code needed to get started. By the end of this article, you'll be equipped to build robots that can measure distance, detect light levels, sense temperature, and even track motion with incredible precision.

Safety First: Understanding Voltage Levels and Protection Circuits

Before connecting any external sensor to your SPIKE Prime, it's crucial to understand the voltage levels involved. The SPIKE Prime hub operates on a 3.3V logic level. This means that the digital input pins are designed to receive signals between 0V and 3.3V. Applying voltages higher than 3.3V can damage the hub. Many readily available sensors operate at 5V. Therefore, you MUST use appropriate voltage dividers or level shifters to ensure that the voltage applied to the SPIKE Prime input pins never exceeds 3.3V.

Voltage Dividers: A Simple Protection Circuit

A voltage divider is a simple circuit that uses two resistors to reduce a voltage to a lower level. It's a cost-effective way to interface 5V sensors with the 3.3V SPIKE Prime. The output voltage of a voltage divider is determined by the following formula:

V_out = V_in * (R₂ / (R₁ + R₂))

Where:

• V_out is the output voltage
• V_in is the input voltage
• R₁ is the resistance of the first resistor
• R₂ is the resistance of the second resistor

For example, to reduce a 5V signal to 3.3V, you can use a 1K resistor (R₁) and a 2K resistor (R₂). This will result in an output voltage of approximately 3.33V. Place the 2K resistor between the SPIKE Prime input pin and ground, and the 1K resistor between the 5V sensor output and the SPIKE Prime input pin. This configuration ensures that the voltage seen by the SPIKE Prime remains within safe limits.

Important: Always double-check your wiring and resistor values before connecting any sensor to your SPIKE Prime. Incorrect wiring or resistor values can damage your hub.

Interfacing with the HC-SR04 Ultrasonic Distance Sensor

The HC-SR04 ultrasonic sensor is a popular and affordable sensor for measuring distances. It works by emitting a short burst of ultrasonic sound and measuring the time it takes for the sound to return after bouncing off an object. The distance to the object can then be calculated using the speed of sound.

Wiring the HC-SR04 to SPIKE Prime

The HC-SR04 has four pins: VCC, Trig, Echo, and GND. Here's how to connect it to your SPIKE Prime:

• VCC: Connect to a 5V power supply. Do NOT connect directly to the SPIKE Prime. Use a separate 5V power source.
• GND: Connect to the ground of your 5V power supply AND the SPIKE Prime ground (any of the ground pins on the SPIKE Prime ports).
• Trig: Connect to a SPIKE Prime output port (e.g., Port A) through a 330-ohm resistor. This limits the current and protects the SPIKE Prime.
• Echo: Connect to a SPIKE Prime input port (e.g., Port B) through a voltage divider (1K and 2K resistors) to reduce the 5V signal to a safe 3.3V level. The 2K resistor goes between the SPIKE Prime input pin and ground.

Important: Using a voltage divider on the Echo pin is crucial to protect the SPIKE Prime from overvoltage. Connecting the Echo pin directly to the SPIKE Prime without a voltage divider will likely damage the hub.

Python Code for HC-SR04

This Python code reads the distance measured by the HC-SR04 sensor:

from spike import PrimeHub, Speaker
import hub
import time

# Define the SPIKE Prime hub and speaker
hub = PrimeHub()
speaker = Speaker()

# Define the pins for the Trig and Echo signals
trig_pin = 'A'  # Change if using a different port
echo_pin = 'B'  # Change if using a different port

def measure_distance():
    """Measures the distance using the HC-SR04 ultrasonic sensor."""
    # Send a short pulse to the Trig pin
    hub.port.A.mode(0)
    hub.port.A.pwm(0)
    time.sleep(0.00001) # 10 microseconds
    hub.port.A.pwm(100)
    time.sleep(0.00001) # 10 microseconds
    hub.port.A.pwm(0)

    # Measure the duration of the Echo pulse
    pulse_start = time.ticks_us()
    pulse_end = pulse_start
    max_duration = 25000 # Maximum duration to wait (microseconds)

    # Wait for the Echo pin to go high (with timeout)
    while hub.port.B.get() == 0:
        pulse_start = time.ticks_us()
        if pulse_start - pulse_end > max_duration:
            print("Timeout waiting for pulse start")
            return -1  # Indicate error

    # Wait for the Echo pin to go low (with timeout)
    pulse_end = pulse_start
    while hub.port.B.get() == 1:
        pulse_end = time.ticks_us()
        if pulse_end - pulse_start > max_duration:
            print("Timeout waiting for pulse end")
            return -1  # Indicate error

    # Calculate the pulse duration
    pulse_duration = pulse_end - pulse_start

    # Calculate the distance in centimeters
    # Speed of sound in air is approximately 343 meters per second (at room temperature)
    # Distance = (Time * Speed) / 2  (divided by 2 because the sound travels to the object and back)
    distance = (pulse_duration * 0.0343) / 2

    return distance

# Main loop
while True:
    distance = measure_distance()
    if distance != -1:
        print("Distance: {:.2f} cm".format(distance))
        speaker.sing(440, 0.2) # Play a short sound
    else:
        print("Error reading distance")
        speaker.sing(220, 0.2) # Play a low sound

    time.sleep(0.5)  # Wait for 0.5 seconds

Troubleshooting HC-SR04

• No reading or constant 'Error reading distance': Check the wiring, especially the connections to VCC, GND, Trig, and Echo. Ensure the voltage divider is correctly implemented on the Echo pin. Verify that the Trig pin is connected to an output port and the Echo pin to an input port.
• Inaccurate readings: Ensure that the sensor is mounted securely and that there are no obstructions in its path. The speed of sound varies with temperature, so extremely hot or cold environments can affect accuracy.
• Timeout errors: If you consistently get timeout errors, try increasing the `max_duration` variable in the code. This will give the sensor more time to return a reading, but it may also slow down the program. Check for reflections from nearby objects that might cause false triggers.

Interfacing with the MPU6050 IMU (Accelerometer/Gyroscope)

The MPU6050 is a popular Inertial Measurement Unit (IMU) that combines a 3-axis accelerometer and a 3-axis gyroscope in a single chip. It communicates using the I2C protocol, which allows multiple devices to share the same two wires.

Wiring the MPU6050 to SPIKE Prime

The MPU6050 has several pins, but we only need four for basic operation:

• VCC: Connect to a 3.3V power supply. You can use the 3.3V output from the SPIKE Prime expansion port.
• GND: Connect to the ground of the SPIKE Prime (any ground pin on the ports).
• SCL: Connect to the SCL pin of a SPIKE Prime port (e.g., Port C).
• SDA: Connect to the SDA pin of the same SPIKE Prime port (e.g., Port C).

Important: The MPU6050 often has a built-in voltage regulator that allows it to operate from a 5V supply, but it's best to use 3.3V to avoid potential issues. Make sure the logic levels are compatible. Some MPU6050 modules have pull-up resistors on the SCL and SDA lines. If not, you might need to add external pull-up resistors (4.7K ohms) between SCL and 3.3V, and SDA and 3.3V.

Python Code for MPU6050

This Python code reads the accelerometer and gyroscope data from the MPU6050:

from spike import PrimeHub
import hub
import time

# Define the SPIKE Prime hub
hub = PrimeHub()

# MPU6050 I2C address
MPU6050_ADDR = 0x68

# Register addresses
PWR_MGMT_1   = 0x6B
ACCEL_XOUT_H = 0x3B
GYRO_XOUT_H  = 0x43

def read_i2c_block(register, length):
    """Reads a block of data from the I2C device."""
    return hub.port.C.i2c_read(MPU6050_ADDR, register, length) # Using Port C

def read_raw_data(register):
    """Reads raw data from the MPU6050."""
    high = read_i2c_block(register, 1)[0]
    low = read_i2c_block(register+1, 1)[0]
    value = (high << 8) + low
    if (value >= 0x8000):
        return -((65535 - value) + 1)
    else:
        return value

def get_acceleration():
    """Gets the acceleration data from the MPU6050."""
    accel_x = read_raw_data(ACCEL_XOUT_H)
    accel_y = read_raw_data(ACCEL_XOUT_H+2)
    accel_z = read_raw_data(ACCEL_XOUT_H+4)

    # Scale the raw data.  The scale factor depends on the configured range.
    # Assuming +/- 2g range (sensitivity of 16384 LSB/g)
    accel_x_scaled = accel_x / 16384.0
    accel_y_scaled = accel_y / 16384.0
    accel_z_scaled = accel_z / 16384.0

    return accel_x_scaled, accel_y_scaled, accel_z_scaled

def get_gyro_data():
    """Gets the gyroscope data from the MPU6050."""
    gyro_x = read_raw_data(GYRO_XOUT_H)
    gyro_y = read_raw_data(GYRO_XOUT_H+2)
    gyro_z = read_raw_data(GYRO_XOUT_H+4)

    # Scale the raw data. The scale factor depends on the configured range.
    # Assuming +/- 250 degrees/sec range (sensitivity of 131 LSB/deg/s)
    gyro_x_scaled = gyro_x / 131.0
    gyro_y_scaled = gyro_y / 131.0
    gyro_z_scaled = gyro_z / 131.0

    return gyro_x_scaled, gyro_y_scaled, gyro_z_scaled

# Wake up the MPU6050
hub.port.C.i2c_write(MPU6050_ADDR, PWR_MGMT_1, bytearray([0])) # Using Port C

# Main loop
while True:
    try:
        accel_x, accel_y, accel_z = get_acceleration()
        gyro_x, gyro_y, gyro_z = get_gyro_data()

        print("Acceleration: X={:.2f}g, Y={:.2f}g, Z={:.2f}g".format(accel_x, accel_y, accel_z))
        print("Gyro: X={:.2f} deg/s, Y={:.2f} deg/s, Z={:.2f} deg/s".format(gyro_x, gyro_y, gyro_z))
        time.sleep(0.1)
    except Exception as e:
        print("I2C Error:", e)
        time.sleep(1)

Troubleshooting MPU6050

• I2C Errors: Double-check the wiring of SDA and SCL. Ensure that the MPU6050 is powered with 3.3V and that the ground is connected. If you're still getting errors, try adding external pull-up resistors (4.7K ohms) to the SDA and SCL lines. Verify that the I2C address (0x68) is correct for your MPU6050 module. Some modules have a different address (0x69) depending on the state of the AD0 pin.
• Inconsistent or No Data: Ensure that the MPU6050 is properly initialized by writing 0 to the PWR_MGMT_1 register. Check the data sheet for your specific MPU6050 module to determine the correct scaling factors for the accelerometer and gyroscope data.
• Drifting: Gyroscopes are prone to drifting over time. You can implement a calibration routine to compensate for this drift by averaging the gyroscope readings over a period of time when the sensor is stationary and subtracting this average from subsequent readings.

Interfacing with Photoresistors (Light Dependent Resistors/LDR)

A photoresistor, also known as a Light Dependent Resistor (LDR), is a resistor whose resistance decreases as the intensity of light increases. They are simple and inexpensive sensors that can be used to detect changes in light levels.

Wiring the Photoresistor to SPIKE Prime

To use a photoresistor with the SPIKE Prime, you'll need to create a voltage divider circuit. Here's how to connect it:

• Connect one end of the photoresistor to a 3.3V power supply from the SPIKE Prime expansion port.
• Connect the other end of the photoresistor to one end of a 10K resistor.
• Connect the other end of the 10K resistor to the ground of the SPIKE Prime (any ground pin on the ports).
• Connect the point where the photoresistor and the 10K resistor meet to a SPIKE Prime input port (e.g., Port D).

The voltage at the input port will vary depending on the light level. When the light level is high, the resistance of the photoresistor will be low, and the voltage at the input port will be close to 0V. When the light level is low, the resistance of the photoresistor will be high, and the voltage at the input port will be close to 3.3V.

Python Code for Photoresistor

This Python code reads the analog value from the photoresistor:

from spike import PrimeHub
import hub
import time

# Define the SPIKE Prime hub
hub = PrimeHub()

# Define the pin for the photoresistor
photoresistor_pin = 'D'  # Change if using a different port

def read_light_level():
    """Reads the light level from the photoresistor."""
    # The SPIKE Prime reads analog values from 0 to 1023
    # The higher the value, the lower the light level
    light_level = hub.port.D.get()
    return light_level

# Main loop
while True:
    light_level = read_light_level()
    print("Light Level:", light_level)
    time.sleep(0.1)

Troubleshooting Photoresistor

• No reading or constant value: Check the wiring of the photoresistor and the 10K resistor. Ensure that the photoresistor is connected to 3.3V and the 10K resistor is connected to ground. Verify that the point where the photoresistor and the 10K resistor meet is connected to a SPIKE Prime input port.
• Values not changing with light: Make sure the photoresistor is exposed to light and that there are no obstructions blocking the light. Try adjusting the value of the 10K resistor. A lower value resistor will make the sensor more sensitive to changes in light levels, while a higher value resistor will make it less sensitive.
• Erratic readings: Photoresistors can be sensitive to noise. Try adding a capacitor (e.g., 0.1uF) between the input pin and ground to filter out noise.

Interfacing with the

The DS18B20 is a digital temperature sensor that communicates using the OneWire protocol. It provides accurate temperature readings and is relatively easy to interface with microcontrollers.

Wiring the DS18B20 to SPIKE Prime

The DS18B20 has three pins:

• VCC: Connect to a 3.3V power supply from the SPIKE Prime expansion port.
• GND: Connect to the ground of the SPIKE Prime (any ground pin on the ports).
• DQ: Connect to a SPIKE Prime input/output port (e.g., Port E) through a 4.7K pull-up resistor. Connect the other end of the 4.7K resistor to the 3.3V supply.

Important: The 4.7K pull-up resistor is essential for the OneWire communication to work correctly. Without it, the SPIKE Prime will not be able to communicate with the DS18B20.

Python Code for DS18B20

This Python code reads the temperature from the DS18B20 sensor. Note that this implementation requires bit-banging the OneWire protocol, which is timing sensitive and may not be perfectly reliable on the SPIKE Prime. An Arduino bridge (described later) is a more robust solution for this sensor.

from spike import PrimeHub
import hub
import time

# Define the SPIKE Prime hub
hub = PrimeHub()

# Define the pin for the DS18B20
ds18b20_pin = 'E'  # Change if using a different port

# OneWire commands
OW_RESET      = 0
OW_READROM    = 0x33
OW_MATCHROM   = 0x55
OW_SKIPROM    = 0xCC
OW_CONVERT    = 0x44
OW_READSCRATCH= 0xBE

def ow_reset():
    """Performs a OneWire reset."""
    hub.port.E.mode(0) # Set to output
    hub.port.E.digital(0)
    time.sleep_us(480)
    hub.port.E.digital(1)
    hub.port.E.mode(1) # Set to input with pull-up
    time.sleep_us(60)
    presence = not hub.port.E.get() # Check for presence pulse
    time.sleep_us(420)
    return presence

def ow_write_bit(bit):
    """Writes a bit to the OneWire bus."""
    hub.port.E.mode(0) # Set to output
    hub.port.E.digital(0)
    if bit:
        time.sleep_us(10)
        hub.port.E.digital(1)
    else:
        time.sleep_us(60)
        hub.port.E.digital(1)
    hub.port.E.mode(1) # Set to input with pull-up
    time.sleep_us(10)

def ow_read_bit():
    """Reads a bit from the OneWire bus."""
    hub.port.E.mode(0) # Set to output
    hub.port.E.digital(0)
    time.sleep_us(2)
    hub.port.E.digital(1)
    hub.port.E.mode(1) # Set to input with pull-up
    time.sleep_us(15)
    bit = hub.port.E.get()
    time.sleep_us(45)
    return bit

def ow_write_byte(byte):
    """Writes a byte to the OneWire bus."""
    for i in range(8):
        ow_write_bit(byte & 1)
        byte >>= 1

def ow_read_byte():
    """Reads a byte from the OneWire bus."""
    byte = 0
    for i in range(8):
        bit = ow_read_bit()
        if bit:
            byte |= (1 << i)
    return byte

def read_temperature():
    """Reads the temperature from the DS18B20 sensor."""
    if not ow_reset():
        print("DS18B20 not found")
        return None

    ow_write_byte(OW_SKIPROM) # Skip ROM
    ow_write_byte(OW_CONVERT) # Convert temperature
    time.sleep(0.75) # Wait for conversion

    if not ow_reset():
        print("DS18B20 not found")
        return None

    ow_write_byte(OW_SKIPROM) # Skip ROM
    ow_write_byte(OW_READSCRATCH) # Read scratchpad

    # Read 9 bytes from scratchpad
    scratchpad = []
    for i in range(9):
        scratchpad.append(ow_read_byte())

    # Extract temperature data
    temp_lsb = scratchpad[0]
    temp_msb = scratchpad[1]

    # Calculate temperature in Celsius
    temperature = ((temp_msb << 8) | temp_lsb) * 0.0625

    return temperature

# Main loop
while True:
    temperature = read_temperature()
    if temperature is not None:
        print("Temperature: {:.2f} °C".format(temperature))
    time.sleep(1)

Troubleshooting DS18B20

• DS18B20 not found: Check the wiring of the DS18B20, especially the connections to 3.3V, ground, and the DQ pin. Ensure that the 4.7K pull-up resistor is connected between the DQ pin and 3.3V. Verify that the DQ pin is connected to a SPIKE Prime input/output port.
• Incorrect temperature readings: The OneWire protocol is timing-sensitive. Ensure that the timing delays in the code are accurate. If you're still getting incorrect readings, try increasing the delay after the `OW_CONVERT` command. Consider using an Arduino bridge for more reliable communication (see below).
• No temperature change: The DS18B20 may be faulty. Try using a different DS18B20 sensor.

Using an Arduino Nano as a Sensor Bridge

Directly interfacing with some sensors, like the DS18B20 or sensors requiring complex communication protocols, can be challenging with the SPIKE Prime due to timing constraints and limited libraries. A robust solution is to use an as a sensor bridge. The Arduino can handle the low-level sensor communication, and then transmit the processed data to the SPIKE Prime via serial communication.

Wiring the Arduino Nano to SPIKE Prime

• Arduino VCC: Connect to a 5V power supply (separate from the SPIKE Prime).
• Arduino GND: Connect to the ground of the 5V power supply AND the SPIKE Prime ground (any ground pin on the ports).
• Arduino TX (digital pin 1): Connect to a SPIKE Prime input port (e.g., Port F). Use a voltage divider (1K and 2K resistors) to reduce the 5V signal to a safe 3.3V level for the SPIKE Prime.
• Arduino RX (digital pin 0): Connect to a SPIKE Prime output port (e.g., Port A). Use a 330-ohm resistor in series to limit current.

Arduino Code (C++)

This Arduino code reads the temperature from a DS18B20 sensor connected to digital pin 2 and sends the temperature to the SPIKE Prime via serial communication.

#include 
#include 

// Data wire is plugged into digital pin 2 on the Arduino
#define ONE_WIRE_BUS 2

// Setup a oneWire instance to communicate with any OneWire devices (not just Maxim/Dallas temperature ICs)
 ;

// Pass our oneWire reference to Dallas Temperature.
; // Start serial communication at 115200 baud
  sensors.begin();      // Start up the library
}

void loop() {
  // Call sensors.requestTemperatures() to issue a global temperature
  // request to all devices on the bus
  sensors.requestTemperatures(); // Send the command to get temperatures
  float temperatureC = sensors.getTempCByIndex(0);

  // Check if reading was successful
  if (temperatureC == DEVICE_DISCONNECTED_C) {
    Serial.println("Error: Could not read temperature data");
  } else {
    Serial.print("Temperature: ");
    Serial.print(temperatureC);
    Serial.println(" C");
    Serial.print("T");  // Add a marker character
    Serial.println(temperatureC); // Send the temperature
  }

  delay(1000); // Wait 1 second before next reading
}

This Python code receives the temperature data from the Arduino via serial communication.

from spike import PrimeHub
import hub
import time

# Define the SPIKE Prime hub
hub = PrimeHub()

# Define the port for serial communication
serial_port = 'F'  # Change if using a different port

def read_temperature_from_arduino():
    """Reads the temperature from the Arduino via serial communication."""
    try:
        # Read serial data until a 'T' is found
        while True:
            data = hub.port.F.read(1)
            if data is None:
                return None # No data
            if len(data) > 0 and chr(data[0]) == 'T':
                break # Marker found

        temperature_str = ""
        while True:
            data = hub.port.F.read(1)
            if data is None:
                return None # No data
            if len(data) == 0:
                continue
            char = chr(data[0])
            if char == '\n' or char == '\r':
                break # End of line
            temperature_str += char

        try:
            temperature = float(temperature_str)
            return temperature
        except ValueError:
            print("Invalid temperature data:", temperature_str)
            return None

    except Exception as e:
        print("Serial communication error:", e)
        return None

# Main loop
while True:
    temperature = read_temperature_from_arduino()
    if temperature is not None:
        print("Temperature from Arduino: {:.2f} °C".format(temperature))
    else:
        print("No temperature data received from Arduino")
    time.sleep(1)

Troubleshooting Arduino Bridge

• No data received: Check the wiring between the Arduino and the SPIKE Prime, especially the connections to TX and RX. Ensure that the Arduino is powered and that the serial communication is initialized correctly in both the Arduino and SPIKE Prime code. Verify that the baud rate (115200) is the same in both codes. Also make sure voltage divider is used on the Arduino TX line.
• Garbled data: This can be caused by incorrect baud rate settings or noise on the serial communication lines. Try reducing the baud rate or adding a capacitor to filter out noise.
• Inconsistent data: Ensure that the sensor is properly connected to the Arduino and that the Arduino code is correctly reading and transmitting the sensor data.

Comparison Table: External vs LEGO Sensors

Sensor Type	LEGO Sensor (SPIKE Prime)	External Sensor	Range	Accuracy	Cost	Notes
Distance	Ultrasonic Sensor	HC-SR04 Ultrasonic Sensor	~200 cm	~1 cm	~2-400 cm	~0.3 cm	Lower	Higher	External sensor offers longer range and potentially higher accuracy at a lower cost. Requires external power and level shifting.
Motion/Orientation	Integrated Gyroscope/Accelerometer		Limited by Hub	Relatively Low	Limited by Hub	Higher	Provides more detailed and accurate motion data than the hub's integrated sensors. Requires I2C communication.
Light	Color Sensor (Reflected Light Intensity)	Photoresistor (LDR)	0-100% reflected light	Relative	0-3.3V (Analog Value)	Relative	Lower	Lowest cost option for detecting changes in ambient light levels. Requires analog input.
Temperature	None (Requires Workaround)		N/A	N/A	-55°C to +125°C	±0.5°C	N/A	Provides accurate temperature readings. Requires OneWire communication or Arduino bridge.

I2C Bus Explanation with Multi-Device Wiring

I2C (Inter-Integrated Circuit) is a serial communication protocol that allows multiple devices to communicate with each other using only two wires: SDA (Serial Data) and SCL (Serial Clock). The SPIKE Prime ports (e.g. Port C) can act as I2C masters, controlling communication with multiple I2C slave devices. Each I2C device has a unique address that the master uses to select the device it wants to communicate with.

Wiring Multiple I2C Devices

To connect multiple I2C devices to the same SPIKE Prime port, simply connect the SDA pins of all the devices together and the SCL pins of all the devices together. You'll also need to connect the ground pins of all the devices together to provide a common ground reference. Remember to use the 3.3V output from the SPIKE Prime expansion port to power the I2C devices, and include pull-up resistors (4.7K ohms) on the SDA and SCL lines if they are not already present on the I2C modules.

Example: Connecting an MPU6050 and a Barometer

Let's say you want to connect an MPU6050 (address 0x68) and a (address 0x76) to Port C of the SPIKE Prime. You would connect the following:

• MPU6050 VCC and BMP280 VCC to 3.3V from SPIKE Prime
• MPU6050 GND and BMP280 GND to GND from SPIKE Prime
• MPU6050 SDA and BMP280 SDA to SDA on Port C
• MPU6050 SCL and BMP280 SCL to SCL on Port C

Your Python code would then need to address each device individually using its I2C address. For example, to read data from the MPU6050, you would use hub.port.C.i2c_read(0x68, register, length), and to read data from the BMP280, you would use hub.port.C.i2c_read(0x76, register, length).

Real FLL/WRO Competition Project Ideas

Integrating external sensors can significantly enhance your robot's performance in FLL and WRO competitions. Here are a few project ideas:

• Obstacle Avoidance: Use the HC-SR04 ultrasonic sensor to detect obstacles in the robot's path and navigate around them. This is essential for autonomous navigation tasks.


• Line Following with : Enhance line following accuracy using multiple photoresistors to more precisely determine the robot's position relative to the line.


• Inclination Detection: Use the MPU6050 IMU to detect the inclination of the robot and adjust its speed accordingly. This can be useful for climbing ramps or navigating uneven terrain