As we all know, microcontrollers play a crucial role in embedded systems by controlling various tasks in devices ranging from household appliances to industrial machinery. One popular family of microcontrollers is the PIC (Peripheral Interface Controller) microcontroller series developed by Microchip Technology. In our previous blogs on PIC microcontrollers, we have covered the process to >getting started with PIC microcontrollers & debugging an embedded app, and another blog will help you learn the >Fundamentals of Programming a PIC Microcontroller. This time we are going to move on and explore the process of writing and reading data from a PIC microcontroller. This blog will provide complete step-by-step instructions and code examples to Write and Read Data from a PIC Microcontroller.

Prerequisites

Before we start the process, here are a few things that we may require during the process:

1. PIC Microcontroller: You can select a PIC microcontroller that suits your project's requirements. For this tutorial, we are using PIC16F877A microcontroller. 

2. Integrated Development Environment (IDE): You'll need an IDE to write, compile, and program the microcontroller. Microchip's MPLAB X IDE is a popular choice.

3. Compiler: A C compiler is essential to write and compile your code. MPLAB XC8 is commonly used for PIC microcontrollers.

4. Hardware: Prepare the necessary hardware components such as the PIC microcontroller, power supply, crystal oscillator (if needed), and any other components specific to your project.

5. Programming Cable/Debugger: A programming cable or debugger interface is required to program the microcontroller.

Writing Data to PIC Microcontroller

Step 1: Set Up the Project

• Launch the MPLAB X IDE and create a new project. After that, Select the target PIC microcontroller and set up the oscillator settings.

• Configure any necessary libraries or headers for your project.

Step 2: Initialize I/O Ports

Use the appropriate functions to configure the I/O pins you intend to use as input or output. For example:

Step 3: Write Data

To write data to an output pin, use the corresponding port register. For example:

Step 4: Compile and Program

• Write your complete code.

• Compile the code using the selected compiler.

• Connect the programming cable/debugger to the microcontroller.

• Program the microcontroller with the compiled code.

Reading Data from PIC Microcontroller

Step 1: Set Up the Project

Create a new project in MPLAB X IDE or open the existing project from the writing example.

Make sure the necessary libraries and headers are included.

Step 2: Initialize I/O Ports

Configure the I/O pins, designating the desired pins as inputs and outputs.

Step 3: Read Data

To read data from an input pin, use the corresponding port register. For example:

Step 4: Compile and Program

• Complete the code for reading data.

• Compile the code with the chosen compiler.

• Connect the debugger/programming cable to the microcontroller.

• The compiled code should be used to program the microcontroller. Example: Simple LED Control

Consider a simple example in which you write code to control an LED connected to RB0 based on the status of an input switch connected to RC2.

Conclusion

Writing and reading data from a PIC microcontroller is fundamental to building embedded systems. By following the steps outlined in this guide, you can effectively control peripherals based on input conditions. Remember to refer to your microcontroller's datasheet for specific register details and further enhance your projects with advanced features and functionalities.