# Exploring Embedded Systems: Programming PSoC with C

## Introduction

Embedded systems play a crucial role in modern electronics, from consumer gadgets to industrial applications. As a Computer Engineering Technology student, I had the opportunity to work with PSoC (Programmable System on Chip) and write a C program to generate and display random characters on an LCD. This blog details my journey through coding, debugging, and testing an embedded system project.

## Understanding the Project

The goal of this project was to use the **PSoC microcontroller** to generate random delays and display characters on an **LCD screen**. The **Pseudo-Random Sequence (PRS) module** was used for generating random numbers, which were then used to create dynamic time intervals for character display.

## Writing the C Code

The program was written in **C** and uploaded to the PSoC microcontroller. Below is a breakdown of the code:

1. **Defining Constants and Variables**
    
    * A message (e.g., "Wednesday") was stored as a character array.
        
    * Two unsigned integer variables (`uint8_t` and `uint16_t`) were defined for random delay calculations.
        
2. **Initializing Components**
    
    * The LCD display and clock were initialized at the start.
        
    * The PRS module was activated to generate random numbers.
        
3. **Main Loop Execution**
    
    * The program continuously generates random delays between **200ms and 600ms**.
        
    * Characters from the message are displayed one by one at these intervals.
        
    * A **500ms delay** is added after the full message is displayed before restarting the loop.
        

## Code Snippet

```c
#include "project.h"
#include <stdio.h>

int main(void)
{
const char Message[] = "THIRSDAY";
uint8 i;
uint16 randomDelay;

LCD_Start();
CLK1_Start();
RandSys_Start();

for (;;)
{
    LCD_ClearDisplay();
    CyDelay(500);

    for (i = 0; i < strlen(Message); i++)
    {
        randomDelay = (RandSys_Read() % 401) + 200;

        LCD_Position(0, i);
        LCD_PutChar(Message[i]);

        CyDelay(randomDelay);
    }
    CyDelay(500);
}

}
```

## Testing and Debugging

Once the code was written, it was uploaded to the **PSoC microcontroller**. Here’s how I tested it:

1. Ensured the LCD properly initialized and displayed text.
    
2. Verified the **random delays** by monitoring how letters appeared on the screen.
    
3. Debugged minor issues related to **timing mismatches** and **display flickering** by adjusting delay values.
    
4. Confirmed that the infinite loop ran **without crashes or memory overflow**.
    

## Key Learnings

* **Importance of PRS**: Using a **Pseudo-Random Sequence Generator** helps create realistic timing variations.
    
* **Efficient Memory Usage**: Embedded systems have limited resources, so optimizing variable types (`uint8_t` and `uint16_t`) is critical.
    
* **Debugging on Embedded Devices**: Unlike traditional programming, debugging in an embedded system requires hardware monitoring and careful observation of output behavior.
    

## Media

%[https://youtu.be/HdMAQ6fbbOg] 

### Animation

%[https://youtu.be/uc2KZqzjCBA] 

## Conclusion

This project enhanced my understanding of **real-time embedded programming** and **hardware-software integration**. By working with **C programming, PSoC microcontrollers, and LCD displays**, I gained hands-on experience with practical applications of embedded systems.