0.6.1 Improved display code

[digitaldcpower] / uart.c

diff --git a/uart.c b/uart.c
new file mode 100644 (file)
index 0000000..72cc33f
--- /dev/null
+++ b/uart.c
@@ -0,0 +1,111 @@
+// vim: set sw=8 ts=8 si et: 
+/********************************************
+* UART interface without interrupt
+* Author: Guido Socher
+* Copyright: GPL
+**********************************************/
+#include <avr/interrupt.h>
+#include <string.h>
+#include <avr/io.h>
+#include "uart.h"
+#define F_CPU 8000000UL  // 8 MHz
+
+void uart_init(void) 
+{
+        unsigned int baud=51;   // 9600 baud at 8MHz
+#ifdef VAR_88CHIP
+        UBRR0H=(unsigned char) (baud >>8);
+        UBRR0L=(unsigned char) (baud & 0xFF);
+        // enable tx/rx and no interrupt on tx/rx 
+        UCSR0B =  (1<<RXEN0) | (1<<TXEN0);
+        // format: asynchronous, 8data, no parity, 1stop bit 
+        UCSR0C = (1<<UCSZ01)|(1<<UCSZ00);
+#else
+        UBRRH=(unsigned char) (baud >>8);
+        UBRRL=(unsigned char) (baud & 0xFF);
+        // enable tx/rx and no interrupt on tx/rx 
+        UCSRB =  (1<<RXEN) | (1<<TXEN);
+        // format: asynchronous, 8data, no parity, 1stop bit 
+        UCSRC = (1<<URSEL)|(3<<UCSZ0);
+#endif
+}
+
+// send one character to the rs232 
+void uart_sendchar(char c) 
+{
+#ifdef VAR_88CHIP
+        // wait for empty transmit buffer 
+        while (!(UCSR0A & (1<<UDRE0)));
+        UDR0=c;
+#else
+        // wait for empty transmit buffer 
+        while (!(UCSRA & (1<<UDRE)));
+        UDR=c;
+#endif
+}
+// send string to the rs232 
+void uart_sendstr(char *s) 
+{
+        while (*s){
+                uart_sendchar(*s);
+                s++;
+        }
+}
+
+void uart_sendstr_p(const prog_char *progmem_s)
+// print string from program memory on rs232 
+{
+        char c;
+        while ((c = pgm_read_byte(progmem_s++))) {
+                uart_sendchar(c);
+        }
+
+}
+
+// get a byte from rs232
+// this function does a blocking read 
+char uart_getchar(void)  
+{
+#ifdef VAR_88CHIP
+        while(!(UCSR0A & (1<<RXC0)));
+        return(UDR0);
+#else
+        while(!(UCSRA & (1<<RXC)));
+        return(UDR);
+#endif
+}
+
+// get a byte from rs232
+// this function does a non blocking read 
+// returns 1 if a character was read
+unsigned char uart_getchar_noblock(char *returnval)  
+{
+#ifdef VAR_88CHIP
+        if(UCSR0A & (1<<RXC0)){
+                *returnval=UDR0;
+                return(1);
+        }
+#else
+        if(UCSRA & (1<<RXC)){
+                *returnval=UDR;
+                return(1);
+        }
+#endif
+        return(0);
+}
+
+// read and discard any data in the receive buffer 
+void uart_flushRXbuf(void)  
+{
+        unsigned char tmp;
+#ifdef VAR_88CHIP
+        while(UCSR0A & (1<<RXC0)){
+                tmp=UDR0;
+        }
+#else
+        while(UCSRA & (1<<RXC)){
+                tmp=UDR;
+        }
+#endif
+}
+