In this lesson, you'll build on your planning from previous lessons by coding the inputs, outputs, and system responses for your embedded system project. This is where your ideas start coming to life through actual programming, turning your design into a working prototype.

We'll guide you through reviewing your system plan, setting up your environment, coding input handling, controlling outputs, integrating them, debugging, and documenting your code. By the end, you'll have a functional embedded system that responds to real-world inputs.

Start by revisiting the embedded system design you created in previous lessons. This plan should outline the problem you're solving, the components involved, and how they interact.

Key Elements to Identify:

• Inputs: These could be sensors (e.g., temperature, light, buttons) providing data to your system. Decide if they're digital (on/off) or analogue (variable values).
• Outputs: These might include actuators (e.g., motors, LEDs) or displays (e.g., screens showing data).
• System Responses: How the system reacts, like turning on a light if a sensor detects motion.

Refer back to your design documents or sketches. Ensure your plan aligns with user needs and uses abstraction to simplify complex interactions (e.g., treating a sensor as a simple 'read value' function).

Before coding, ensure your development environment is ready for programming your embedded system.

Steps to Follow:

1. Install or open your Integrated Development Environment (IDE) suitable for your platform (e.g., a code editor with support for uploading to hardware).
2. Install any necessary libraries or drivers for your microcontroller and components (e.g., sensor libraries).
3. Connect your hardware if using physical devices, or set up a simulator for testing.
4. Test a simple 'hello world' program, like blinking an LED, to confirm everything works.

Now, write code to read data from your input devices. Focus on handling signals correctly, whether digital or analogue.

Approach:

• For digital inputs: Check if the input is high (on) or low (off).
• For analogue inputs: Read a value (e.g., 0-1023) and convert it if needed (e.g., to temperature).
• Test in a loop to continuously monitor the input.

initialize input pin  // e.g., for button or sensor

loop forever:
    input_value = read from input pin
    if analogue:
        converted_value = map input_value to real unit  // e.g., voltage to temperature
    print input_value  // or store it
    wait 0.5 seconds

Next, develop code to control your output devices. Use conditions or loops to make them respond based on logic.

Approach:

• Set outputs high/low for digital (e.g., turn LED on/off).
• Use loops for repeated actions (e.g., blinking).
• Add simple conditions, like if a value exceeds a threshold.

initialize output pin  // e.g., LED

loop forever:
    if condition met:  // e.g., timer or simple check
        set output pin to high
    else:
        set output pin to low
    wait 1 second