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Software

Overview

Welcome to the Software Onboarding for the 2025-2026 school year!

Goals

  • Learning
    • How do we write software in SCR?
    • How does a microcontroller control hardware?
  • practical
    • Writing Arduino/ C++ code
    • Managing software dependencies
    • Reading software documentation

Downloads

Arduino:

Go here and download the version of the arduino IDE for your operating system (Windows, OSX, linux).

Pico board support:

We'll be using the Raspberry Pi Pico 2 for onboarding. To develop on the pico, you need to add an additional board manager URL to the Arduino IDE.

Go here and scroll to the installation section. Follow the short directions there.

In the boards manager tab, search for these two libraries and install them

Compilation

Select the Pico 2:

Use the Arduino IDE to select the Pico 2 as the compilation target.

Connect the Pico 2 to your computer using a micro-usb cable. You should see this drop down turn bold.

Verifying Source Code:

Copy this skeleton code into an arduino sketch file.

#define LED1_PIN 13
#define LED2_PIN 14
#define LED3_PIN 15

#define IR1_PIN 0
#define IR2_PIN 1
#define IR3_PIN 2
#define IR4_PIN 3
#define IR5_PIN 4

#define MOTOR2_IN3 18
#define MOTOR2_IN4 19

#define MOTOR1_IN1 20
#define MOTOR1_IN2 21

#define SERVO_PIN 22

Servo payloadServo;

void driveForward() {
  // right motor
  digitalWrite(MOTOR1_IN1, HIGH); 
  digitalWrite(MOTOR1_IN2, LOW);

  // left motor
  digitalWrite(MOTOR2_IN3, HIGH);
  digitalWrite(MOTOR2_IN4, LOW);
}

void dumpPayload(Servo servo) {
  servo.write(180);
}

void setup() {
  // IR Pin Setup
  pinMode(IR1_PIN, INPUT);
  pinMode(IR2_PIN, INPUT);
  pinMode(IR3_PIN, INPUT);
  pinMode(IR4_PIN, INPUT);
  pinMode(IR5_PIN, INPUT);
  
  // LED Setup
  pinMode(LED1_PIN, OUTPUT);
  pinMode(LED2_PIN, OUTPUT);
  pinMode(LED3_PIN, OUTPUT);
  pinMode(LED_BUILTIN, OUTPUT);

  // Motor setup
  pinMode(MOTOR1_IN1, OUTPUT);
  pinMode(MOTOR1_IN2, OUTPUT);

  pinMode(MOTOR2_IN3, OUTPUT);
  pinMode(MOTOR2_IN4, OUTPUT);

  // Servo setup
  pinMode(SERVO_PIN, 22);
  payloadServo.attach(SERVO_PIN);
}

void loop() {
  // put your main code here, to run repeatedly:
  driveForward();
  delay(500);
  dumpPayload();
  delay(500);
}

This file contains #defines for the Pico 2's inputs and outputs as well as a function to drive both motors forward.

Edit the setup() function and add the line

digitalWrite(LED1_PIN, HIGH);

Click the check mark at the top left of the IDE to check for compilation errors. If your program compiles correctly you should see this output.

Flashing Pico 2:

Click the arrow at the top left of the IDE to flash the Pico 2. If flashing doesn't work, you may need to unplug the Pico 2 and hold the BOOTSEL button while reconnecting the micro-usb cable.

If your flash is successful, you should see this output, and LED1 should be turned on.

Useful Documentation

Motor Driver:

You shouldn't need more than this truth table, but if you'd like to read the full documentation you can do that here.

Arduino:

Arduino API, Servos, Search

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