--- /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 */
+}