usart.h

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/**
 * @file usart.h
 * @ingroup bme280
 * @author Jason Duffy
 * @date 15th March 2022
 * @brief Driver file providing core USART communication between the target MCU
 * and your PC. This file was adapted from Elliot Williams' Github repo
 * hexagon5un (link in the see also section below).
 * NOTE: This driver does involve blocking waits, this may be improved on in a
 * later version. 
 * @bug No known bugs. 
 * @see https://github.com/hexagon5un/AVR-Programming
 */
 
 
#ifndef BAUD          // If not defined in Makefile
#define BAUD  9600    // Set a safe default baud rate
#endif
 
#ifndef USART_DOT_H
#define USART_DOT_H
 
#include <stdint.h>
 
// These are defined for convenience
#define   USART_HAS_DATA   bit_is_set(UCSR0A, RXC0)
#define   USART_READY      bit_is_set(UCSR0A, UDRE0)
 
 
/**
 * Takes the defined BAUD and F_CPU, calculates the bit-clock multiplier,
 * configures the hardware USART ready for use.
 */
void init_usart(void);
 
 
/**
 * Utility function to transmit a string.
 * @param my_string is the string constant youd like to print, and should be
 * enclosed in "" quotation marks. 
 */
void usart_print_string(const char my_string[]);
 
 
/**
 * Define a string variable, pass it to this function. The string will contain.
 * whatever you typed over serial.
 * @param my_string is a pointer to the first element in the character array
 * you'd like to store the received message in. 
 * @param max_length is the maximum number of characters expected.
 */
void usart_read_string(char my_string[], uint8_t max_length);
 
 
/**
 * Prints a byte out as its 3-digit ascii equivalent.
 * @param byte is the 8 bits of data to be sent, must be unsigned. 
 */
void usart_print_byte(uint8_t byte);
 
 
/**
 * Prints a byte out as its 1-digit ascii equivalent.
 * @param byte is the 8 bits of data to be sent, must be unsigned, with a
 * value of 0-9;
 */
void usart_print_decimal_digit(uint8_t byte);
 
 
/**
 * Prints a byte out as its 1-character ascii equivalent.
 * @param byte is the character to be sent.
 */
void usart_print_char(char byte);
 
 
/**
 * Prints a word (16-bits) out as its 5-digit ascii equivalent.
 * @param word is the 16 bits of data to be sent, must be unsigned.
 */
void usart_print_word(uint16_t word);
 
 
/**
 * Prints a byte out in 1s and 0s.
 * @param byte is the 8 bits of data to be sent, must be unsigned.
 */
void usart_print_binary_byte(uint8_t byte);
 
 
/**
 * Convert a nibble to a hex character.
 * @param nibble is the 4 bits of data to be sent, must be unsigned. 
 */
char usart_nibble_to_hex_character(uint8_t nibble);
 
 
/**
 * Prints a byte out in hexadecimal format.
 * @param byte is the 8 bits of data to be sent, must be unsigned. 
 */
void usart_print_hex_byte(uint8_t byte);
 
 
/**
 * Takes in up to three ascii digits, converts them to a byte when press enter.
 * @returns an unsigned 8 bit integer is returned - this is the data received. 
 */ 
uint8_t usart_get_number(void);
 
 
#endif // USART_DOT_H
 
/*** end of file ***/