uart.h

#ifndef UART_H_
#define	UART_H_

#include <stdint.h>
#include <stdbool.h>

/*
 * Initialize UART module. Set up rx and tx buffers, set up module,
 * and enable the requisite interrupts
 */
void init_uart(void);

/*
 * Send a single byte over UART. Note that this isn't a blocking function,
 * it just pushes your byte into a to_send buffer, which will, at some point
 * in the future, pop your byte out over UART. This buffer guarantees ordering,
 * so earlier calls to this will be sent out over UART first.
 *
 * Don't call this function from an interrupt context, it's not thread safe.
 */
void uart_transmit_byte(uint8_t tx);

/*
 * A lot like transmitting a single byte, except there are multiple bytes. tx does
 * not need to be null terminated, that's why we have the len parameter
 *
 * tx: pointer to an array of bytes to send
 * len: the number of bytes that should be sent from that array
 */
void uart_transmit_buffer(uint8_t *tx, uint8_t len);

/*
 * returns true if there's a byte waiting to be read from the UART module
 */
bool uart_byte_available(void);

/*
 * pops a byte from the receive buffer and returns it. Don't call this
 * function unless uart_byte_available is returning true. Don't call this
 * function from an interrupt context.
 */
uint8_t uart_read_byte(void);

/*
 * handler for all UART1 module interrputs. That is, PIR3:U1IF, U1EIF, U1TXIF, and U1RXIF
 * this function clears the bits in PIR3 that it handles.
 */
void uart_interrupt_handler(void);

#endif	/* UART_H */