I'm working on writing drivers for the peripherals in my ATmega2560 microcontroller. One of these is a USART which has the option of being double speed or normal speed. If this was C for the PC I would use <stdbool.h> to create a boolean member of the USART struct and write my header and source file as shown below.

//usart.h
#ifndef USART_H
#define USART_H

#include <stdbool.h>

typedef enum { USART_PARITY_NONE, USART_PARITY_EVEN, USART_PARITY_ODD } usart_parity_t;
typedef enum { USART_STOP_1, USART_STOP_2 } usart_stopbits_t;
typedef enum { USART_BITS_5, USART_BITS_6, USART_BITS_7, USART_BITS_8} usart_databits_t;

typedef struct
{
	usart_parity_t parity;
	usart_stopbits_t stopbits;
	usart_databits_t databits;
	bool doublespeed;
} usart_t;

//Prototype functions below

#endif

//usart.c
#include <stdint.h>
#include <stdbool.h>
#include "usart.h"
static void set_baud(uint32_t baud, bool doublespeed)
{
	if(doublespeed)
	{
                //Setup usart for double speed
	}
	else
	{
                //Setup usart for normal speed
	}
        //do more stuff
}

However, <stdbool.h> is not provided by the C library implementation available for the ATmega2560.

Question: How do I handle this in my code? Should I use uint8_t doublespeed instead? Are there any consequences of doing this?

posted 6 months ago

CC BY-SA 4.0

6mo ago by Lundin‭

Carl‭

186 reputation 9 0 37 14