Enable callbacks and CR separator in UART library

firmware/uart.c

@@ -9,9 +9,15 @@
 #define RBUF_FORWARD(BUF_IDX, MOD_MASK) BUF_IDX = RBUF_NEXT(BUF_IDX, MOD_MASK)
 #define RBUF_EMPTY(BUFF) (BUFF.head == BUFF.tail)
 
+#define CR 0x0D
+#define LF 0x0A
+
 volatile RBUF(UART_RX_BUF_SIZE) rx_buffer;
 volatile RBUF(UART_TX_BUF_SIZE) tx_buffer;
 
+volatile uint8_t lines = 0;
+void (*uart_handler)(char* line);
+
 void uart_init(void)
 {
 	UBRRH = (uint8_t) (__UBRR>>8);
@@ -48,11 +54,45 @@ void uart_puti(int16_t value, int16_t radix)
 
 char uart_getc(void)
 {
-  if(RBUF_EMPTY(rx_buffer)) return 0;
+  if(RBUF_EMPTY(rx_buffer)) return -1;
   RBUF_FORWARD(rx_buffer.tail, UART_RX_BUF_MASK);
   return rx_buffer.data[rx_buffer.tail];
 }
 
+void uart_gets(char* buf)
+{
+  char c;
+
+  if(lines)
+  {
+    while((c = uart_getc()))
+    {
+      if(c == CR || c < 0) break;
+      *buf++ = c;
+    }
+
+    *buf = 0;
+    --lines;
+  }
+}
+
+void uart_bind_handler(void (*handler)(char* line))
+{
+  uart_handler = handler;
+}
+
+void uart_handle_event(char* buf)
+{
+  if(lines)
+  {
+    if(uart_handler)
+    {
+      uart_gets(buf);
+      (*uart_handler)(buf);
+    }
+  }
+}
+
 ISR(USART_UDRE_vect)
 {    
   if(!RBUF_EMPTY(tx_buffer)) 
@@ -67,8 +107,21 @@ ISR(USART_UDRE_vect)
 }
 
 ISR(USART_RXC_vect)
-{
-  RBUF_FORWARD(rx_buffer.head, UART_RX_BUF_MASK);
-	rx_buffer.data[rx_buffer.head] = UDR;
+{  
+  register uint8_t head = RBUF_NEXT(rx_buffer.head, UART_RX_BUF_MASK);
+  register char data = UDR;
+
+  if(head == rx_buffer.tail)
+  {
+    rx_buffer.head = rx_buffer.tail;
+  }
+  else switch(data)
+  {
+    case 0: case LF: break;
+    case CR: ++lines;
+    default: 
+      rx_buffer.head = head;
+      rx_buffer.data[head] = data;
+  }
 }