Embedded Programming¶

Microcontroller Datasheet¶

For this assignment

I used an Arduino Uno R3, which is based on the ATmega328P microcontroller.

I reviewed the ATmega328P datasheet and learned some important specifications:

Architecture: 8-bit AVR RISC-based microcontroller.
Operating Voltage: 5V (standard for the Uno board).
Clock Speed: 16 MHz (crystal oscillator on the Uno).
Memory: 32 KB Flash (for your code), 2 KB SRAM (for variables), and 1 KB EEPROM.
Pinout Features: Note which pins support PWM (Pulse Width Modulation) and which ones are for ADC (Analog to Digital Conversion).
Digital I/O pins: 14
Analog input pins: 6
Communication protocols: SPI I2C

The ATmega328P is suitable for simple embedded systems because it is easy to program and supports many input and output devices.

Project Description¶

For this assignment, I connected a micro servo motor to the Arduino Uno R3 and controlled it using a simple Arduino program.

The servo motor rotates to different positions according to the programmed instructions.

This demonstrates how a microcontroller can interact with an output device.

Programmed a Board to Interact and Communicate¶

I used:

Arduino Uno R3

Micro servo motor (SG90)

Jumper wires

USB cable

Computer with Arduino IDE

Wiring Connections¶

I connected the micro servo motor to the Arduino Uno R3 as follows:

Servo GND → Arduino GND
Servo VCC → Arduino 5V
Servo Signal → Digital Pin 9 (~9)

Then, I connected the Arduino Uno R3 to my computer using a USB cable and uploaded the program using Arduino IDE.

This setup allowed the Arduino to communicate with the servo motor and control its movement.

Programming Process¶

I used the example Sweep program from the Arduino Servo library.

First, I included the Servo library, which allows Arduino to control servo motors.

Then, I created a servo object called servo_9 and attached it to digital pin 9.

In the setup function, the servo was initialized and configured to operate within a pulse range of 500 to 2500 microseconds.

Inside the loop function, the servo rotates from 0 degrees to 180 degrees one degree at a time. After reaching 180 degrees, it rotates back to 0 degrees.

A delay of 15 milliseconds is added between each movement to give the servo enough time to reach the next position.

The process repeats continuously, creating a smooth back-and-forth sweeping motion.

Code¶

#include <Servo.h>

int pos = 0;

Servo servo_9;

void setup()
{
  servo_9.attach(9, 500, 2500);
}

void loop()
{
  for (pos = 0; pos <= 180; pos += 1) {
    servo_9.write(pos);
    delay(15); 
  }
  for (pos = 180; pos >= 0; pos -= 1) {
    servo_9.write(pos);
    delay(15); 
  }

#include <Servo.h> imports the Servo library.
int pos = 0; creates a variable to store the servo angle.
Servo servo_9; creates a servo object.
servo_9.attach(9, 500, 2500); attaches the servo to digital pin 9.
servo_9.write(pos); moves the servo to the selected angle.
delay(15); gives the servo time to move.
The first loop rotates the servo from 0° to 180°.
The second loop rotates the servo from 180° back to 0°.