Async uart

src/main.c

@@ -1,38 +1,57 @@
 #include <stdio.h>
 #include <string.h>
 #include <avr/io.h>
+#include <avr/interrupt.h>
 #include <avr/pgmspace.h>
 #include <util/delay.h>
 #include "hmi_msg.h"
-#include "uart.h"
+#include "../lib/andygock_avr-uart/uart.h"
+#include "uart_wrap.h"
 #include "print_helper.h"
 #include "../lib/hd44780_111/hd44780.h"
 
+#define BAUDRATE 9600
 #define BLINK_DELAY_MS 100
 
-int main (void)
+// For configuring arduino mega pin 25
+#define LED_INIT DDRA |= _BV(DDA3);
+#define LED_ON PORTA |= _BV(PORTA3)
+#define LED_OFF PORTA &= ~_BV(PORTA3)
+#define LED_DELAY _delay_ms(BLINK_DELAY_MS)
+
+static inline void init_hw (void)
 {
-    /* Init */
-    DDRA |= _BV(DDA3);
-    uart0_init();
-    uart3_init();
+    // IO init
+    /// Set arduino pin 25 as output
+    LED_INIT;
+
+    // UART init
+    uart0_init(UART_BAUD_SELECT(BAUDRATE, F_CPU));
+    uart3_init(UART_BAUD_SELECT(BAUDRATE, F_CPU));
     stdout = stdin = &uart0_io;
     stderr = &uart3_out;
+
+    // LCD init
     lcd_init();
     lcd_clrscr();
-    /* End init */
 
-    /* Print version info to stderr */
+    // Enable interupts
+    sei();
+}
+
+static inline void start_ui (void)
+{
+    // Print program and libc versions
     fprintf_P(stderr, PSTR(PROG_VERSION),
               PSTR(GIT_DESCR), PSTR(__DATE__), PSTR(__TIME__));
     fprintf_P(stderr, PSTR(LIBC_VERSION), PSTR(__AVR_LIBC_VERSION_STRING__));
-    /* End version print */
 
+    // print student name
     fprintf_P(stdout, PSTR(STUD_NAME));
-    fputc('\n', stdout); /* Add a new line to the uart printout */
+    fputc('\n', stdout); // Add a new line to the uart printout
     lcd_puts_P(PSTR(STUD_NAME));
 
-    /* ASCII table print */
+    // ASCII table print
     print_ascii_tbl(stdout);
     unsigned char ascii[128];
     for (unsigned char i = 0; i < sizeof(ascii); i++) {
@@ -40,17 +59,16 @@ int main (void)
     }
     print_for_human(stdout, ascii, sizeof(ascii));
 
-    while (1) {
-        /* set pin 3 high to turn led on */
-        PORTA |= _BV(PORTA3);
-        _delay_ms(BLINK_DELAY_MS);
-
-        /* Month search and print */
-        char letter;
     fprintf_P(stdout, PSTR(GET_MONTH_MSG));
+}
+
+static inline void search_month (void)
+{
+    char letter;
+
     fscanf(stdin, "%c", &letter);
     fprintf(stdout, "%c\n", letter);
-        lcd_goto(0x40); /* Got to the beginning of the next line */
+    lcd_goto(0x40); // Got to the beginning of the next line
     for (int i = 0; i < 6; i++) {
         if (!strncmp_P(&letter, (PGM_P)pgm_read_word(&months[i]), 1)) {
             fprintf_P(stdout, (PGM_P)pgm_read_word(&months[i]));
@@ -60,10 +78,24 @@ int main (void)
         }
     }
 
-        lcd_puts_P(PSTR("                ")); /* Clear the end of the line */
+    lcd_puts_P(PSTR("                ")); // Clear the end of the line
+    fprintf_P(stdout, PSTR(GET_MONTH_MSG));
+}
 
-        /* set pin 3 low to turn led off */
-        PORTA &= ~_BV(PORTA3);
-        _delay_ms(BLINK_DELAY_MS);
+int main (void)
+{
+    init_hw();
+    start_ui();
+
+    while (1) {
+        LED_ON;
+        LED_DELAY;
+
+        if (uart0_available()) {
+            search_month();
+        }
+
+        LED_OFF;
+        LED_DELAY;
     }
 }

src/uart.c

@@ -1,72 +0,0 @@
-#include <avr/io.h>
-#include <stdio.h>
-
-#ifndef F_CPU
-#define F_CPU 16000000UL
-#endif
-
-#ifndef BAUD
-#define BAUD 9600
-#endif
-#include <util/setbaud.h>
-
-/* http://www.cs.mun.ca/~rod/Winter2007/4723/notes/serial/serial.html */
-
-void uart0_init(void)
-{
-    UBRR0H = UBRRH_VALUE;
-    UBRR0L = UBRRL_VALUE;
-#if USE_2X
-    UCSR0A |= _BV(U2X0);
-#else
-    UCSR0A &= ~(_BV(U2X0));
-#endif
-    UCSR0C = _BV(UCSZ01) | _BV(UCSZ00); /* 8-bit data */
-    UCSR0B = _BV(RXEN0) | _BV(TXEN0);   /* Enable RX and TX */
-}
-
-void uart3_init(void)
-{
-    UBRR3H = UBRRH_VALUE;
-    UBRR3L = UBRRL_VALUE;
-#if USE_2X
-    UCSR3A |= _BV(U2X3);
-#else
-    UCSR3A &= ~(_BV(U2X3));
-#endif
-    UCSR3C = _BV(UCSZ31) | _BV(UCSZ30); /* 8-bit data */
-    UCSR3B = _BV(TXEN3);   /* Enable TX */
-}
-
-int uart0_putchar(char c, FILE *stream)
-{
-    (void) stream;
-
-    if (c == '\n') {
-        uart0_putchar('\r', stream);
-    }
-
-    loop_until_bit_is_set(UCSR0A, UDRE0);
-    UDR0 = c;
-    return 0;
-}
-
-int uart3_putchar(char c, FILE *stream)
-{
-    (void) stream;
-
-    if (c == '\n') {
-        uart3_putchar('\r', stream);
-    }
-
-    loop_until_bit_is_set(UCSR3A, UDRE3);
-    UDR3 = c;
-    return 0;
-}
-
-int uart0_getchar(FILE *stream)
-{
-    (void) stream;
-    loop_until_bit_is_set(UCSR0A, RXC0);
-    return UDR0;
-}

src/uart.h

@@ -1,17 +0,0 @@
-#ifndef _UART_H_
-#define _UART_H_
-
-int uart0_putchar(char c, FILE *stream);
-int uart0_getchar(FILE *stream);
-
-int uart3_putchar(char c, FILE *stream);
-
-void uart0_init(void);
-void uart3_init(void);
-
-/* http://www.ermicro.com/blog/?p=325 */
-
-FILE uart0_io = FDEV_SETUP_STREAM(uart0_putchar, uart0_getchar, _FDEV_SETUP_RW);
-FILE uart3_out = FDEV_SETUP_STREAM(uart3_putchar, NULL, _FDEV_SETUP_WRITE);
-
-#endif /* _UART_H_ */

src/uart_wrap.c

@@ -0,0 +1,33 @@
+#include <avr/io.h>
+#include <stdio.h>
+#include "../lib/andygock_avr-uart/uart.h"
+
+int uart0_putc_wrap(char c, FILE *stream)
+{
+    (void) stream;
+
+    if (c == '\n') {
+        uart0_putc_wrap('\r', stream);
+    }
+
+    uart0_putc(c);
+    return 0;
+}
+
+int uart0_getc_wrap(FILE *stream)
+{
+    (void) stream;
+    return (char)uart0_getc();
+}
+
+int uart3_putc_wrap(char c, FILE *stream)
+{
+    (void) stream;
+
+    if (c == '\n') {
+        uart3_putc_wrap('\r', stream);
+    }
+
+    uart3_putc(c);
+    return 0;
+}

src/uart_wrap.h

@@ -0,0 +1,15 @@
+#ifndef _UART_H_
+#define _UART_H_
+
+int uart0_putc_wrap(char c, FILE *stream);
+int uart0_getc_wrap(FILE *stream);
+
+int uart3_putc_wrap(char c, FILE *stream);
+
+
+/* http://www.ermicro.com/blog/?p=325 */
+
+FILE uart0_io = FDEV_SETUP_STREAM(uart0_putc_wrap, uart0_getc_wrap, _FDEV_SETUP_RW);
+FILE uart3_out = FDEV_SETUP_STREAM(uart3_putc_wrap, NULL, _FDEV_SETUP_WRITE);
+
+#endif /* _UART_H_ */