# HG changeset patch
# User John Tsiombikas <nuclear@member.fsf.org>
# Date 1488923445 -7200
# Node ID c47d05df066750ca61f7c59af6795baa43c8b747

initial commit

diff -r 000000000000 -r c47d05df0667 .hgignore
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/.hgignore	Tue Mar 07 23:50:45 2017 +0200
@@ -0,0 +1,6 @@
+\.o$
+\.swp$
+\.eep$
+\.hex$
+\.map$
+^test_ftdi$
diff -r 000000000000 -r c47d05df0667 Makefile
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Makefile	Tue Mar 07 23:50:45 2017 +0200
@@ -0,0 +1,38 @@
+src = $(wildcard *.c)
+obj = $(src:.c=.o)
+bin = test_ftdi
+hex = $(bin).hex
+eep = $(bin).eep
+
+mcu_gcc = atmega644p
+mcu_dude = m644p
+
+CC = avr-gcc
+OBJCOPY = avr-objcopy
+
+CFLAGS = -Os -pedantic -Wall -mmcu=$(mcu_gcc) -DXTAL=14745600
+LDFLAGS = -Wl,-Map,$(bin).map -mmcu=$(mcu_gcc) -lprintf_min
+
+.PHONY: all
+all: $(hex) $(eep)
+
+$(bin): $(obj)
+	$(CC) -o $@ $(obj) $(LDFLAGS)
+
+$(hex): $(bin)
+	$(OBJCOPY) -j .text -j .data -O ihex -R .eeprom $< $@
+
+$(eep): $(bin)
+	$(OBJCOPY) -j .eeprom --change-section-lma .eeprom=0 -O ihex $< $@
+
+.PHONY: fuses
+fuses:
+	avrdude -c usbtiny -p $(mcu_dude) -U lfuse:w:0xf7:m -U hfuse:w:0x99:m -U efuse:w:0xff:m
+
+.PHONY: program
+program: $(hex)
+	avrdude -c usbtiny -p $(mcu_dude) -e -U flash:w:$(hex)
+
+.PHONY: clean
+clean:
+	rm -f $(bin) $(obj) $(hex) $(eep) $(bin).map
diff -r 000000000000 -r c47d05df0667 serial.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/serial.c	Tue Mar 07 23:50:45 2017 +0200
@@ -0,0 +1,106 @@
+#ifdef XTAL
+#define F_CLK	XTAL
+#define F_CPU	XTAL
+#else
+#warning "compiled for 1mhz internal rc osc. serial comms won't work"
+#define F_CLK	1000000
+#define F_CPU	1000000
+#endif
+
+#include <stdio.h>
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <util/delay.h>
+#include <avr/power.h>
+
+static int uart_send_char(char c, FILE *fp);
+static int uart_get_char(FILE *fp);
+
+#define BUF_SZ	64
+#define BUF_IDX_MASK	0x3f
+#define NEXT_IDX(x)	(((x) + 1) & BUF_IDX_MASK)
+static char outbuf[BUF_SZ];
+static volatile unsigned char out_rd, out_wr;
+static char inbuf[BUF_SZ];
+static volatile unsigned char in_rd, in_wr;
+
+static FILE std_stream = FDEV_SETUP_STREAM(uart_send_char, uart_get_char, _FDEV_SETUP_RW);
+
+
+
+void init_serial(long baud)
+{
+	unsigned int ubrr_val = F_CLK / 16 / baud - 1;
+
+	power_usart0_enable();
+
+	/* set baud generator timer reset value */
+	UBRR0H = (unsigned char)(ubrr_val >> 8);
+	UBRR0L = (unsigned char)ubrr_val;
+
+	/* enable rx/tx and recv interrupt */
+	UCSR0B = (1 << RXEN0) | (1 << TXEN0) | (1 << RXCIE0);
+	/* set frame format: 8n1 */
+	UCSR0C = 3 << UCSZ00;
+
+	stdin = stdout = stderr = &std_stream;
+}
+
+int have_input(void)
+{
+	return in_wr != in_rd;
+}
+
+static int uart_send_char(char c, FILE *fp)
+{
+	int next;
+
+	if(c == '\n') {
+		uart_send_char('\r', fp);
+	}
+
+	next = NEXT_IDX(out_wr);
+	while(next == out_rd);
+
+	outbuf[out_wr] = c;
+	out_wr = next;
+
+	/* enable the Tx data register empty interrupt */
+	UCSR0B |= 1 << UDRIE0;
+	return 0;
+}
+
+static int uart_get_char(FILE *fp)
+{
+	char c;
+
+	while(in_rd == in_wr);
+
+	c = inbuf[in_rd];
+	in_rd = NEXT_IDX(in_rd);
+	return c;
+}
+
+ISR(USART0_RX_vect)
+{
+	char c = UDR0;
+
+	if(c == '\r') {
+		c = '\n';
+	}
+
+	inbuf[in_wr] = c;
+	in_wr = NEXT_IDX(in_wr);
+}
+
+/* USART Tx data register empty (can send more data) */
+ISR(USART0_UDRE_vect)
+{
+	if(out_rd != out_wr) {
+		UDR0 = outbuf[out_rd];
+		out_rd = NEXT_IDX(out_rd);
+	} else {
+		/* no more data to send for now, disable the interrupt */
+		UCSR0B &= ~(1 << UDRIE0);
+	}
+}
diff -r 000000000000 -r c47d05df0667 serial.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/serial.h	Tue Mar 07 23:50:45 2017 +0200
@@ -0,0 +1,7 @@
+#ifndef SERIAL_H_
+#define SERIAL_H_
+
+void init_serial(long baud);
+int have_input(void);
+
+#endif	/* SERIAL_H_ */
diff -r 000000000000 -r c47d05df0667 test.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test.c	Tue Mar 07 23:50:45 2017 +0200
@@ -0,0 +1,45 @@
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include "serial.h"
+
+void procmd(const char *cmd);
+
+#define MAX_INPUT_SIZE	128
+static char input[MAX_INPUT_SIZE];
+static unsigned char inp_cidx;
+
+int main(void)
+{
+	init_serial(38400);
+	sei();
+
+	printf("welcome!\n");
+
+	for(;;) {
+		while(have_input()) {
+			int c = getchar();
+			putchar(c);
+
+			if(c == '\r' || c == '\n') {
+				input[inp_cidx] = 0;
+				procmd(input);
+				inp_cidx = 0;
+			} else if(inp_cidx < sizeof input - 1) {
+				input[inp_cidx++] = c;
+			}
+		}
+	}
+	return 0;
+}
+
+void procmd(const char *cmd)
+{
+	if(strcmp(cmd, "info") == 0) {
+		printf("test firmware v0\n");
+	} else {
+		printf("unknown command: %s\n", cmd);
+	}
+}