X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=common%2Fserial.c;fp=common%2Fserial.c;h=2bf6901836064ece4517047dcb8d94f70838d99f;hb=9c37d18b9c70fdb70dfec453398c4649e9e57586;hp=0000000000000000000000000000000000000000;hpb=49b6b6ad84ec47b4f9eb9ef131975cc5b72372a2;p=model-railway-devices.git

diff --git a/common/serial.c b/common/serial.c
new file mode 100644
index 0000000..2bf6901
--- /dev/null
+++ b/common/serial.c
@@ -0,0 +1,22 @@
+#include <avr/io.h>
+#include "serial.h"
+
+#define BIT(n) (1<<(n))
+
+void serial_init(uint16_t baud)
+{
+	DDRD = (DDRD&~0x03) | 0x02;
+	PORTD &= ~0x03;
+
+	baud = (F_CPU/16+baud/2)/baud-1;
+	UBRR0H = baud>>8;
+	UBRR0L = baud;
+	UCSR0C = BIT(UCSZ00) | BIT(UCSZ01);  // 8N1
+	UCSR0B = BIT(RXEN0) | BIT(TXEN0) | BIT(RXCIE0);
+}
+
+void serial_write(uint8_t c)
+{
+	while(!(UCSR0A&(1<<UDRE0))) ;
+	UDR0 = c;
+}