--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Makefile	Sun May 06 23:13:14 2012 +0800
@@ -0,0 +1,102 @@
+# Name: Makefile
+# Author: <insert your name here>
+# Copyright: <insert your copyright message here>
+# License: <insert your license reference here>
+
+# This is a prototype Makefile. Modify it according to your needs.
+# You should at least check the settings for
+# DEVICE ....... The AVR device you compile for
+# CLOCK ........ Target AVR clock rate in Hertz
+# OBJECTS ...... The object files created from your source files. This list is
+#                usually the same as the list of source files with suffix ".o".
+# PROGRAMMER ... Options to avrdude which define the hardware you use for
+#                uploading to the AVR and the interface where this hardware
+#                is connected. We recommend that you leave it undefined and
+#                add settings like this to your ~/.avrduderc file:
+#                   default_programmer = "stk500v2"
+#                   default_serial = "avrdoper"
+# FUSES ........ Parameters for avrdude to flash the fuses appropriately.
+
+DEVICE     = atmega8
+CLOCK      = 8000000
+PROGRAMMER = #-c stk500v2 -P avrdoper
+OBJECTS    = main.o
+FUSES      = -U hfuse:w:0xd9:m -U lfuse:w:0x24:m
+
+# ATMega8 fuse bits used above (fuse bits for other devices are different!):
+# Example for 8 MHz internal oscillator
+# Fuse high byte:
+# 0xd9 = 1 1 0 1   1 0 0 1 <-- BOOTRST (boot reset vector at 0x0000)
+#        ^ ^ ^ ^   ^ ^ ^------ BOOTSZ0
+#        | | | |   | +-------- BOOTSZ1
+#        | | | |   +---------- EESAVE (set to 0 to preserve EEPROM over chip erase)
+#        | | | +-------------- CKOPT (clock option, depends on oscillator type)
+#        | | +---------------- SPIEN (if set to 1, serial programming is disabled)
+#        | +------------------ WDTON (if set to 0, watchdog is always on)
+#        +-------------------- RSTDISBL (if set to 0, RESET pin is disabled)
+# Fuse low byte:
+# 0x24 = 0 0 1 0   0 1 0 0
+#        ^ ^ \ /   \--+--/
+#        | |  |       +------- CKSEL 3..0 (8M internal RC)
+#        | |  +--------------- SUT 1..0 (slowly rising power)
+#        | +------------------ BODEN (if 0, brown-out detector is enabled)
+#        +-------------------- BODLEVEL (if 0: 4V, if 1: 2.7V)
+#
+# For computing fuse byte values for other devices and options see
+# the fuse bit calculator at http://www.engbedded.com/fusecalc/
+
+
+# Tune the lines below only if you know what you are doing:
+
+AVRDUDE = avrdude $(PROGRAMMER) -p $(DEVICE)
+COMPILE = avr-gcc -Wall -Os -DF_CPU=$(CLOCK) -mmcu=$(DEVICE) -g
+
+# symbolic targets:
+all:	main.hex
+
+.c.o:
+	$(COMPILE) -c $< -o $@
+
+.S.o:
+	$(COMPILE) -x assembler-with-cpp -c $< -o $@
+# "-x assembler-with-cpp" should not be necessary since this is the default
+# file type for the .S (with capital S) extension. However, upper case
+# characters are not always preserved on Windows. To ensure WinAVR
+# compatibility define the file type manually.
+
+.c.s:
+	$(COMPILE) -S $< -o $@
+
+flash:	all
+	$(AVRDUDE) -U flash:w:main.hex:i
+
+fuse:
+	$(AVRDUDE) $(FUSES)
+
+# Xcode uses the Makefile targets "", "clean" and "install"
+install: flash fuse
+
+# if you use a bootloader, change the command below appropriately:
+load: all
+	bootloadHID main.hex
+
+clean:
+	rm -f main.hex main.elf $(OBJECTS)
+
+# file targets:
+main.elf: $(OBJECTS)
+	$(COMPILE) -o main.elf $(OBJECTS)
+
+main.hex: main.elf
+	rm -f main.hex
+	avr-objcopy -j .text -j .data -O ihex main.elf main.hex
+	avr-size --format=avr --mcu=$(DEVICE) main.elf
+# If you have an EEPROM section, you must also create a hex file for the
+# EEPROM and add it to the "flash" target.
+
+# Targets for code debugging and analysis:
+disasm:	main.elf
+	avr-objdump -d main.elf
+
+cpp:
+	$(COMPILE) -E main.c

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.c	Sun May 06 23:13:14 2012 +0800
@@ -0,0 +1,125 @@
+/* Name: main.c
+ * Author: <insert your name here>
+ * Copyright: <insert your copyright message here>
+ * License: <insert your license reference here>
+ */
+
+#include <avr/io.h>
+#include <stdio.h>
+#include <string.h>
+#include <util/crc16.h>
+
+// configuration params
+// - measurement interval
+// - transmit interval
+// - bluetooth params
+// - number of sensors (and range?)
+
+static int uart_putchar(char c, FILE *stream);
+static FILE mystdout = FDEV_SETUP_STREAM(uart_putchar, NULL,
+        _FDEV_SETUP_WRITE);
+
+static uint8_t n_measurements;
+static uint8_t measurements[500];
+
+static uint8_t readpos;
+static char readbuf[30];
+
+static void 
+uart_init(unsigned int baud)
+{
+    // baud rate
+    UBRRH = (unsigned char)(baud >> 8);
+    UBRRL = (unsigned char)baud;
+    UCSRB = (1<<RXEN)|(1<<TXEN);
+    //8N1
+    UCSRC = (1<<URSEL)|(3<<UCSZ0);
+}
+
+static int 
+uart_putchar(char c, FILE *stream)
+{
+    // XXX should sleep in the loop for power.
+    loop_until_bit_is_set(UCSRA, UDRE);
+    UDR = c;
+    return 0;
+}
+
+static void
+cmd_fetch()
+{
+    uint16_t crc = 0;
+    int i;
+    printf("%d measurements\n", n_measurements);
+    for (i = 0; i < n_measurements; i++)
+    {
+        printf("%3d : %d\n", i, measurements[i]);
+        crc = _crc_ccitt_updatec(crc, measurements[i]);
+    }
+        printf("CRC : %d\n", i, measurements[i]);
+}
+
+static void
+cmd_clear()
+{
+}
+
+static void
+cmd_btoff()
+{
+}
+
+static void
+read_handler()
+{
+    if (strcmp(readbuf, "fetch") == 0)
+    {
+        cmd_fetch();
+    }
+    else if (strcmp(readbuf, "clear") == 0)
+    {
+        cmd_clear();
+    }
+    else if (strcmp(readbuf, "btoff") == 0)
+    {
+        cmd_btoff();
+    }
+    else
+    {
+        printf("Bad command\n");
+    }
+}
+
+ISR(UART_RX_vect)
+{
+    char c = UDR;
+    if (c == '\n')
+    {
+        readbuf[readpos] = '\0';
+        read_handler();
+        readpos = 0;
+    }
+    else
+    {
+        readbuf[readpos] = c;
+        readpos++;
+        if (readpos >= sizeof(readbuf))
+        {
+            readpos = 0;
+        }
+    }
+}
+
+int main(void)
+{
+    uart_init(9600);
+
+    fprintf(&mystdout, "hello %d\n", 12);
+
+    // get current time
+
+    for(;;){
+        /* insert your main loop code here */
+    }
+    return 0;   /* never reached */
+}