Group Assignment 10: Measurement of Power Consumption of an Output Device

Team: Manuel Ayala-Chauvin, Sandra Nuñez-Torres
Institution: Fablab - Universidad Tecnológica Indoamérica
Year: 2025

Output Device Selected

For this assignment, we selected a servo motor model MZ996. This type of servo is commonly used in electronic projects due to its metal gears, which offer better resistance and durability during mechanical movements.

Connection Setup

The servo motor has three wires:

• VCC (red) – connected to 5V DC power supply.
• GND (black or brown) – connected to ground.
• Signal (orange or yellow) – connected to a PWM output of the development board (e.g., Arduino).

The servo is controlled using a PWM signal and operates at 5V DC.

Wokwi simulation

Program Execution

A basic program was uploaded to the development board to rotate the servo motor periodically.

				
#include 

Servo servoMotor;

void setup() {
  Serial.begin(9600);
  servoMotor.attach(9);
  servoMotor.write(0);
}

void loop() {
  for (int i = 0; i <= 180; i++) {
    servoMotor.write(i);
    delay(25);
  }

  for (int i = 179; i > 0; i--) {
    servoMotor.write(i);
    delay(25);
  }
}

Wokwi simulation

Measurement Procedure

To measure the power consumption:

• Voltage was measured in parallel with the servo motor.
• Current was measured in series.

A digital multimeter was used to capture the voltage and current values during the operation of the servo.

Observations

• Voltage behavior during operation: Voltage variation video
• Current behavior during operation: Current variation video

Since the servo was not under load (not moving any external weight), the current consumption remained low and stable.

Conclusion

The measurement of power consumption showed that:

• The voltage remained around 5V with minor fluctuations.
• The current draw was minimal, which aligns with the unloaded condition of the motor.
• Proper use of the multimeter (parallel for voltage, series for current) is essential for accurate power measurements.

In this assignment, an output device was added to a previously designed and fabricated development board using an ATTINY412 microcontroller. The chosen output devices were two servo motors, which were controlled through programming using the developed board.

Step 1: Electronic Schematic Design

Initially, an electronic schematic was created considering the devices to be connected. Each servo motor includes three pins: VCC (power), GND (ground), and a control signal that enables its movement. The initial schematic diagram is shown below:

Step 2: PCB Design

After defining the schematic, the printed circuit board (PCB) was designed. This process carefully organized connections to ensure both servo motors were powered through a single connection, facilitating the necessary control signals from the microcontroller.

Step 3: Gerber File Generation and Configuration

From the PCB design, Gerber files detailing electrical paths and required drillings were generated. These files were configured and subsequently converted into G-code format, ready for use on the Monofab SRM-20 milling machine.

Step 4: PCB Manufacturing

The PCB manufacturing was performed using the Monofab SRM-20 milling machine, ensuring precision in electrical connections and necessary drillings for electronic components.

Step 5: Soldering and Connections

With the PCB manufactured, necessary electronic components, including the ATTINY412 microcontroller and specific servo motor connections, were soldered.

Step 6: Microcontroller Programming

Once the circuit was fully assembled, the code required to control both servo motors was developed. The code was designed for coordinated and precise movement, showcasing the ATTINY412’s capability to effectively manage external devices.

Step 7: Testing and Validation

Finally, the code was loaded onto the microcontroller, and the servo motors' functionality was tested. The obtained results demonstrated correct operation, confirming the effectiveness of the design and programming.

Test Video: https://youtube.com/shorts/YDQ0HEVnBxA

Conclusion

This project successfully demonstrated integrating output devices with custom electronic boards, showcasing skills in electronic design, digital fabrication, programming, and functional validation. This methodology can be replicated by following the detailed steps above, allowing students and professionals to adapt the procedure according to their specific needs.