AVR Pin Debugging Utility

This utility provides functions to print pin states and debug AVR microcontrollers in a Linux terminal via UART. It allows developers to inspect register values and individual pin statuses easily.

Functions

1. print_binary(const char* register_name, uint8_t value)

Prints the binary representation of an 8-bit AVR register or pin value to the terminal.

• Parameters:
  • register_name: A string (e.g., "PINB") to label the output for clarity.
  • value: The 8-bit value (e.g., PINB) to be displayed in binary format.
• Output: Prints the register name followed by its binary value (e.g., PINB: 10110011).
• Example:

  print_binary("PINB", PINB);

  Output in terminal:

  PINB: 10110011
  

2. printf(const char* format, ...)

Standard C-style formatted output function, redirected to UART for terminal display.

• Parameters:
  • format: A format string (e.g., "PD2 status: %d\n") specifying the output format.
  • ...: Additional arguments (e.g., pin_value) to be formatted.
• Output: Prints formatted text to the terminal via UART.
• Example:

  printf("PD2 status: %d\n", pin_value);

  Output in terminal:

  PD2 status: 1
  

Setup Instructions

To use this utility, initialize UART and redirect the standard output to the UART interface:

1. Include the UART utility: Include the uart.c file, which contains the UART initialization and output functions.

   #include "uart.c"

2. Initialize UART: Call uart_init() to configure the UART module with the appropriate baud rate and settings.

   uart_init();

3. Redirect stdout to UART: Set the standard output stream (stdout) to the UART output stream (uart_output) to send all printf outputs to the terminal.

   stdout = &uart_output;

Example Code

#include <avr/io.h>
#include "uart.c"

int main(void) {
    // Initialize UART
    uart_init();
    stdout = &uart_output;

    // Example usage
    print_binary("PINB", PINB); // Print PINB register in binary
    printf("PD2 status: %d\n", (PIND & (1 << PD2)) >> PD2); // Print PD2 pin status

    while (1) {
        // Your application code
    }
    return 0;
}

Notes

• Ensure uart.c is in your project directory and configured for your AVR microcontroller (e.g., correct baud rate, clock frequency).
• The pin_value used in printf should be derived from the appropriate register (e.g., PIND & (1 << PD2) for PD2).
• This utility assumes a Linux terminal with a serial monitor (e.g., minicom, screen) configured to receive UART output.
• Verify your AVR’s clock frequency and UART settings match the uart.c implementation to avoid communication issues.