Added a serial0_flush_rxbuf() function

avr_usart.c

@@ -7,6 +7,7 @@
 #include <avr/io.h>
 #include <avr/interrupt.h>
 #include <avr/sleep.h>
+#include <stdint.h>
 #include <util/delay.h>
 #include "avr_usart.h"
 
@@ -30,14 +31,17 @@ int main() {
     
     uint8_t buf_len = 12;
     //unsigned char data[12] = "snd 12chars\0";
-    unsigned char data[1] = "A";
+    //unsigned char data[1] = "A";
-    
+    unsigned char data = '0'; 
 
     while(1) {
-        serial0_write(data, buf_len);
+        //serial0_write(data, buf_len);
-        _delay_ms(1000);
+        tx_usart0(data);
-        serial0_read(data, buf_len);
+        //serial0_read(data, buf_len);
-        led_blink();     
+        //data = rx_usart0();
+        serial0_flush_rxbuf();
+        serial0_read(data, 1);
+        //led_blink();     
     }
     
     return 0;
@@ -66,8 +70,6 @@ void init_usart0(void) {
     UBRR0H |= (uint8_t) (0x33>>8);
     UBRR0L |= (uint8_t) 0x33;
 
-
-
     //Enable recv and Transmit pins, overrides other uses.
     //IN the usart control and status register 0B
     UCSR0B = (1<<RXEN0) | (1<<TXEN0);
@@ -103,12 +105,18 @@ void tx_usart0(unsigned char data) {
  */
 unsigned char rx_usart0(void) {
     //first wait for the data to be received.
-    while(!(UCSR0A & (1<<RXC0))) {
+    while( !(UCSR0A & (1<<RXC0)) ) {
         ;//Equiv of continue
     }
 
     //now return the data
-    return (unsigned char) UDR0;
+    return UDR0;
+}
+
+
+void serial0_flush_rxbuf(void) {
+    uint8_t none;
+    while( UCSR0A & (1<<RXC0)) none = UDR0;
 }
 
 
@@ -139,13 +147,46 @@ void serial0_write(unsigned char* buffer, uint8_t write_length) {
  */
 void serial0_read(unsigned char* buffer, uint8_t buf_length) {
     //clear buffer out?
-    buffer = 0;
+    //buffer = 0;
     for(uint8_t i = 0; i < buf_length; i++) {
         buffer[i] = rx_usart0();
     }
 }
 
 
+/*
+ * Inupt: A serialbuffer and length
+ * Output: None
+ * Description: Reads the serial data into a buffer of x length, 
+ * it does error checking from the register first.
+ */
+void serial0_read_with_err_checking(unsigned char* buffer, uint8_t buf_length) {
+     //first wait for the data to be received.
+    while( !(UCSR0A & (1<<RXC0)) ) {
+        ;//Equiv of continue
+    }
+    
+    //check for errors in the register.
+    //Check for frame error.
+    if(UCSR0A & (1<<FE0)) {
+        led_blink();
+    }
+    //check for data over-run
+    else if(UCSR0A & (1<<DOR0)) {
+        led_blink();
+        led_blink();
+    }
+    //check for parity error
+    else if(UCSR0A & (1<<UPE0)) {
+        led_blink();
+        led_blink();
+        led_blink();
+    }
+
+    //now return the data
+    buffer[0] = UDR0;   
+}
+
 
 /*
  * Inupt: BUAD RATE as uint8_t

avr_usart.h

@@ -6,6 +6,7 @@
  */
 
 #include <inttypes.h>
+#include <stdint.h>
 
 //#############################
 //PIN DEFINES AND CONSTS
@@ -48,9 +49,10 @@ unsigned char rx_usart0(void);
 
 void serial0_write(unsigned char* buffer, uint8_t write_length);
 void serial0_read(unsigned char* buffer, uint8_t buf_length);
+void serial0_read_with_err_checking(unsigned char* buffer, uint8_t buf_length);
 void serial0_set_baud(uint8_t baud);
 void seiral0_enable_timeouts(uint8_t ms);
-
+void serial0_flush_rxbuf(void);