Build an Experimental Magnetic Loop Antenna with Arduino and Stepper Motor

Building an Experimental Magnetic Loop Antenna with a Stepper Motor and an Arduino

If you're interested in outdoor activities like camping, amateur radio, or even just looking for a more reliable way to communicate, building a magnetic loop antenna with a stepper motor and an Arduino can be a great way to stay connected. This project is relatively straightforward and can be completed with basic supplies and tools. By the end of it, you'll have a device capable of aiding in communication over a wide range of frequencies.

Parts Needed

• 1 x Arduino Uno board
• 1 x Stepper motor
• 2 x 220Ω Resistors
• 1 x 9V Battery Clip
• 1 x 10nF Capacitor
• 2 x 15cm Copper Wire
• 1 x Prototyping board
• 1 x Magnetic Loop Antenna

Instructions

1. First, connect the 9V battery clip to your protoboard. Then, solder one of the copper wires from the battery clip to the positive (+) side of the stepper motor. Solder the other copper wire from the battery clip to the negative (-) side of the motor. This will act as the power source for the stepper motor.

2. Next, connect the two 220Ω resistors to the + and - sides of the motor. Connect the ends of the resistors to the digital pins 0 and 1 on the Arduino board.

3. Connect the 10nF capacitor to the Uno board’s AREF pin. This will act as a reference voltage for the stepper motor.

4. Finally, attach the antenna to the central axis of the stepper motor. Make sure the antenna is securely fastened to the motor.

Once you've completed the above steps, your magnetic loop antenna with a stepper motor and an Arduino is ready to use. Now, you'll be able to capture a range of signals from all sorts of sources, allowing you to stay connected no matter where you are.

Here's an example source code for building an experimental magnetic loop antenna with a stepper motor and an Arduino. This code uses the AccelStepper library to control the stepper motor and the Arduino's analog input pins to read data from the magnetic loop antenna's sensor.

#include <AccelStepper.h>

#define DIR_PIN 2
#define STEP_PIN 3

#define SENSOR_PIN A0

// Change these values to match your antenna's sensor calibration
#define SENSOR_MIN 0
#define SENSOR_MAX 1023

AccelStepper stepper(AccelStepper::DRIVER, STEP_PIN, DIR_PIN);

void setup() {
  Serial.begin(9600);
  stepper.setMaxSpeed(2000);
  stepper.setAcceleration(1000);
}

void loop() {
  int sensorValue = analogRead(SENSOR_PIN);
  int mappedValue = map(sensorValue, SENSOR_MIN, SENSOR_MAX, 0, 359);
  Serial.println(mappedValue);
  
  stepper.moveTo(mappedValue);
  stepper.runToPosition();
  delay(1000);
}

In this code, the AccelStepper library is used to control the stepper motor connected to pins 2 and 3 of the Arduino board. The SENSOR_PIN is connected to the magnetic loop antenna's sensor and reads analog data, which is then mapped to a value between 0 and 359 degrees. This value is used to set the target position of the stepper motor using stepper.moveTo(), and then the motor is moved to that position using stepper.runToPosition(). Finally, a delay of 1 second is added to allow the motor to settle before reading the sensor data again.

Note that the SENSOR_MIN and SENSOR_MAX values in the code should be adjusted to match your specific magnetic loop antenna's sensor calibration. Additionally, you may need to adjust the stepper.setMaxSpeed() and stepper.setAcceleration() values to match your stepper motor's specifications.

Conclusion

Building a magnetic loop antenna with a stepper motor and an Arduino is a relatively easy project that can be completed with basic tools and supplies. You'll be able to receive signals from a wide range of sources, allowing you to stay connected no matter where you are. If you're ready to experiment with building an antenna and staying connected, give this project a try!