X-Git-Url: https://defiant.homedns.org/gitweb/?p=ros_wild_thumper.git;a=blobdiff_plain;f=avr%2Fnano%2Fuart.c;fp=avr%2Fnano%2Fuart.c;h=1a3707a781ba3dcab4d28c1df79b214207489ace;hp=0000000000000000000000000000000000000000;hb=4053424236542640b1cb23624877725d5ae8e50f;hpb=34bae39fabd9b44e1d169087e8d18d542f4f1525

diff --git a/avr/nano/uart.c b/avr/nano/uart.c
new file mode 100644
index 0000000..1a3707a
--- /dev/null
+++ b/avr/nano/uart.c
@@ -0,0 +1,97 @@
+#include <stdlib.h>
+#include "uart.h"
+#include <avr/interrupt.h>
+
+#define UART_UBRR_CALC(BAUD_,FREQ_) ((FREQ_)/((BAUD_)*16L)-1)
+
+static volatile	char read[RINGBUFFER_LEN];
+static volatile	char *in_read_ptr;
+static volatile	char *out_read_ptr;
+
+ISR(USART_RX_vect) {
+	// update read from uart
+	if (UCSR0A & (1<<RXC0)) {
+		*in_read_ptr = UDR0;
+
+		if (in_read_ptr < read + RINGBUFFER_LEN - 1) in_read_ptr++;
+		else in_read_ptr = (char *)read;
+	}
+}
+
+
+void setup_uart(unsigned int rate) {
+	UCSR0B |= (1<<TXEN0) | (1<<RXEN0); // UART TX & RX
+	UCSR0B |= (1<<RXCIE0); 		// RX Interrupt
+	UCSR0C |= (3<<UCSZ00); // Asynchron 8N1
+
+	UBRR0H = (uint8_t)(UART_UBRR_CALC(rate, F_CPU) >> 8);
+	UBRR0L = (uint8_t)UART_UBRR_CALC(rate, F_CPU);
+
+	in_read_ptr = out_read_ptr = read;
+}
+
+
+void uart_putc(char *c) {
+	while (!(UCSR0A & (1<<UDRE0)));
+	UDR0 = *c;
+}
+
+
+int uart_putchar(char c, FILE *stream)
+{
+	uart_putc(&c);
+	return 0;
+}
+
+
+void uart_puts(char *s) {
+	char *c;
+
+	for (c = s; *c != '\0'; c++)
+		uart_putc(c);
+}
+
+
+int uart_getchar(FILE *stream)
+{
+	return uart_getc();
+}
+
+
+int uart_getc() {
+	while (!(UCSR0A & (1<<RXC0)));
+	return UDR0;
+}
+
+
+void uart_setup_stdout() {
+	fdevopen(uart_putchar, uart_getchar);
+}
+
+
+void uart_stream_update(ringbuffer_t *buffer) {
+	// update write to uart
+	if (buffer->out_write_ptr != buffer->in_write_ptr) {
+		if (UCSR0A & (1<<UDRE0)) {
+			UDR0 = *buffer->out_write_ptr;
+			if (buffer->out_write_ptr < buffer->write + RINGBUFFER_LEN - 1) buffer->out_write_ptr++;
+			else buffer->out_write_ptr = buffer->write;
+		}
+	}
+
+	// update read from uart	
+	if (in_read_ptr != out_read_ptr) {
+		*buffer->in_read_ptr = *out_read_ptr;
+
+		// update newline chars
+		if (buffer->block_read == *buffer->in_read_ptr) buffer->newlines++;
+
+		if (buffer->in_read_ptr < buffer->read + RINGBUFFER_LEN - 1) buffer->in_read_ptr++;
+		else buffer->in_read_ptr = buffer->read;
+
+		// move pointer
+		if (out_read_ptr < read + RINGBUFFER_LEN - 1) out_read_ptr++;
+		else out_read_ptr = read;
+	}
+}
+