Group assignment: demonstrate and compare the toolchains and development workflows for available embedded architectures

1. Raspberry Pi Pico W Overview

For this week’s assignment, I reviewed the Raspberry Pi Pico, a cost-effective and flexible development board built around the RP2040 microcontroller. This chip includes a dual-core ARM Cortex-M0+ processor capable of running at up to 133 MHz, making it suitable for embedded and real-time applications. It provides 264 KB of SRAM and 2 MB of Flash memory, which support a range of control and processing tasks.

The board includes 26 general-purpose I/O pins, many of which support functions such as I2C, SPI, UART, PWM, and ADC, offering a wide variety of interfacing possibilities for sensors, actuators, and communication devices.

Processor and Performance

• Dual-core ARM Cortex-M0+ processor, up to 133 MHz
• Optimized for low-power, real-time processing
• Includes hardware timers and interrupt capabilities
• Supports deep sleep and dormant modes for power efficiency

Memory

• 264 KB of Static RAM (SRAM)
• 2 MB of onboard QSPI Flash storage

Input/Output Capabilities

• 26 multifunction GPIO pins (22 accessible for general use)
• 8 PWM channels for tasks such as motor or LED control
• 3 analog inputs with 12-bit ADC resolution
• Internal temperature sensor

Communication Interfaces

• I2C, SPI, and UART support for peripheral communication
• Micro-USB port for both power supply and programming
• Programmable using C/C++ or MicroPython
• SWD (Serial Wire Debug) interface available for debugging

Power and Voltage

• Operating voltage range: 1.8V to 5.5V
• Logic level: 3.3V
• Low-power modes suitable for battery-operated systems

Physical Characteristics

• Dimensions: 21 mm x 51 mm
• 40-pin Dual Inline Package (DIP) layout for breadboard compatibility

2. Components

• Arduino Board
• A4988 Stepper Motor Driver
• Stepper Motor
• Potentiometer
• External Power Supply

3. Circuit Connections

The stepper motor is connected to the A4988 driver, which is controlled by the Arduino.

• STEP (A4988) → Pin 9
• DIR (A4988) → Pin 8
• POT (Analog Input) → 28

4. Arduino Code

        
#define DIR_PIN 2
#define STEP_PIN 3
#define POT_PIN 28 

void setup() {
  pinMode(STEP_PIN, OUTPUT);
  pinMode(DIR_PIN, OUTPUT);
  digitalWrite(STEP_PIN, LOW);
}

void loop() {
  int potValue = analogRead(POT_PIN);
  int stepDelay = map(potValue, 0, 1023, 1, 10);


  digitalWrite(DIR_PIN, HIGH);
  for (int i = 0; i < 200; i++) {
    digitalWrite(STEP_PIN, HIGH);
    digitalWrite(STEP_PIN, LOW);
    delay(stepDelay);
  }

  delay(500); 


  digitalWrite(DIR_PIN, LOW);
  for (int i = 0; i < 200; i++) {
    digitalWrite(STEP_PIN, HIGH);
    digitalWrite(STEP_PIN, LOW);
    delay(stepDelay);
  }

  delay(1000); 
}