Timer Based Digital Stopwatch

Project Overview

This project implements a digital stopwatch using the PIC12F1572 microcontroller. The stopwatch uses Timer1 to count milliseconds and displays the elapsed time over UART in the format MM:SS:MS. The project is evaluated using software simulation in MPLAB X IDE.

Objective

• Implement a digital stopwatch using Timer1.
• Display elapsed time over UART in the format MM:SS:MS.
• Use software simulation in MPLAB X IDE to evaluate functionality.

Skills Tested

• ✅ Timer configuration (1ms resolution)
• ✅ UART data formatting (Sending real-time updates)
• ✅ Interrupt handling
• ✅ Software simulation debugging

Task Details

1. Use Timer1 to count milliseconds.
2. Convert time to Minutes:Seconds:Milliseconds (MM:SS:MS) format.
3. Send the formatted time over UART every second.
4. Use a software breakpoint in MPLAB X to verify correct time updates.

Table of Contents

• Prerequisites
• Building the Project
• Apparatus
• Uploading to the Microcontroller
• Usage
• Troubleshooting

Prerequisites

• MPLAB X IDE
• XC8 Compiler
• PIC16F877A Microcontroller
• Proteus (optional)

Building the Project

1. Open the project in MPLAB X IDE.
2. Ensure the XC8 compiler is selected.
3. Build the project to generate the .hex or .cof file.
4. Alternatively, you can build the project using Visual Studio Code with the MPLAB extension. Set the project output file path, name, and extension using Ctrl+Shift+P and selecting "Edit Project Properties".

Apparatus

The circuit simulation can be found here.

Necessary components that can't be changed:

1. PIC12(L)F1572/3 microcontroller: To run the program.
2. UART module (configured to 8bit receive with 9600 Baud rate): To receive and interpret output.

Optional components depending on your circuit:

1. Button: For start/stop.
2. 1 Resistors.

Uploading to the Microcontroller

After building the project, upload the generated .hex or .cof file to the PIC16F877A microcontroller using a suitable programmer. The file can be found in either of the following paths:

1. In case of using MPLAB X IDE: dist\default\debug\Timer_Based_Digital_Stopwatch.X.debug.cof
2. In case of using Visual Studio Code (if the file name was set as default): out\Timer_Based_Digital_Stopwatch\default.hex

Usage

1. The code is largely customizable, however for changing USART pins please consult the datasheet

Troubleshooting

• Ensure all connections are secure and correct.
• Verify the microcontroller is programmed with the correct .hex or .cof file.
• Check the power supply to the microcontroller and other components.