1 files changed, 101 insertions, 0 deletions
diff --git a/serial.c b/serial.c
new file mode 100644
index 0000000..418a97d
--- /dev/null
+++ b/serial.c
@@ -0,0 +1,101 @@
+/*
+ * Copyright 2012 (C) Christian Franke <nobody at nowhere dot ws>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with This program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#define BAUD 38400
+
+#include <avr/interrupt.h>
+#include <avr/io.h>
+#include <util/setbaud.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "serial.h"
+
+
+static char output_buffer[512];
+static uint16_t output_offset = 0;
+static uint16_t output_end = 0;
+
+static char input_buffer[512];
+static uint16_t input_end = 0;
+
+static uint8_t verbose = 0;
+
+void serial_send(const char *buffer, uint16_t len, uint8_t urgent)
+{
+	if (!urgent && !verbose)
+		return;
+
+	cli();
+
+	if (sizeof(output_buffer) - output_end < len) {
+		memmove(output_buffer, output_buffer + output_offset, output_end -
+				output_offset);
+		output_end -= output_offset;
+		output_offset = 0;
+	}
+
+	uint16_t size = len;
+
+	if (size > sizeof(output_buffer) - output_end)
+		size = sizeof(output_buffer) - output_end;
+
+	memcpy(&output_buffer[output_end], buffer, size);
+
+	uint8_t send_needed = output_end == output_offset;
+
+	output_end += size;
+	sei();
+
+	if (send_needed) {
+		output_offset++;
+		UDR = output_buffer[output_offset - 1];
+	}
+}
+
+ISR(USART_TXC_vect)
+{
+	if (output_end == output_offset)
+		return;
+
+	UDR = output_buffer[output_offset];
+	output_offset++;
+}
+
+ISR(USART_RXC_vect)
+{
+	if (input_end == sizeof(input_buffer))
+		input_end = 0;
+
+	input_buffer[input_end++] = UDR;
+	input_end -= serial_rx_cb(input_buffer, input_end);
+}
+
+void serial_toggle_verbose(void)
+{
+	verbose = 1 - verbose;
+}
+
+void serial_init(void)
+{
+	UBRRH = UBRRH_VALUE;
+	UBRRL = UBRRL_VALUE;
+	UCSRA = 0x00;
+	UCSRB = (1 << RXCIE) | (1 << TXCIE) | (1 << RXEN) | (1 << TXEN);
+	UCSRC = (1 << URSEL) | (1 << UCSZ1) | (1 << UCSZ0);
+}