Move master branch from from mios git repo

2014-01-23 00:23:15 +01:00
commit 609d9e5be9
352 changed files with 53418 additions and 0 deletions
@@ -0,0 +1,63 @@
+/* 
+ * Copyright (c) 2009 Andrew Smallbone <andrew@rocketnumbernine.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <ds1305.h>
+
+#ifdef __cplusplus
+extern "C"{
+#endif
+
+unsigned char ds1305_transfer(unsigned char address, unsigned char data)
+{
+  select_ds1305();
+  send_spi(address);
+  unsigned char out = send_spi(data);
+  deselect_ds1305();
+  return out;
+}
+
+void ds1305_write_block(unsigned char address, unsigned char *data, int length)
+{
+  select_ds1305();
+  send_spi(address+DS1305_WRITE);
+  int i;
+  for (i=0; i<length; i++) {
+    send_spi(*data++);
+  }
+  deselect_ds1305();
+}
+
+void ds1305_read_block(unsigned char address, unsigned char *data, int length)
+{
+  select_ds1305();
+  send_spi(address);
+  int i;
+  for (i=0; i<length; i++) {
+    *(data+i) = send_spi(0xFF);
+  }
+  deselect_ds1305();
+}
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
@@ -0,0 +1,115 @@
+/* 
+ * Copyright (c) 2009 Andrew Smallbone <andrew@rocketnumbernine.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef _ds1305_h__
+#define _ds1305_h__
+
+#include <spi.h>
+
+#ifdef __cplusplus
+extern "C"{
+#endif
+
+// these should be defined to the operation used to select/deselect the DS1305
+void select_ds1305(void);
+void deselect_ds1305(void);
+
+#define DS1305_WRITE 0x80
+#define DS1305_TIME 0x00
+#define DS1305_ALARM0 0x07
+#define DS1305_ALARM1 0x0B
+#define DS1305_CONTROL 0x0F
+#define DS1305_STATUS 0x010
+#define DS1305_CHARGER 0x11
+#define DS1305_USERRAM 0x20
+
+#define DS1305_ALARM_SET 0x80
+
+// send the address and a byte and returns the byte returned by the DS1305
+unsigned char ds1305_transfer(unsigned char address, unsigned char data);
+// write a block of bytes - will add 0x80 to the address
+void ds1305_write_block(unsigned char address, unsigned char *data, int length);
+// read a block of bytes
+void ds1305_read_block(unsigned char address, unsigned char *data, int length);
+
+typedef struct _DS1305_DATETIME
+{
+  unsigned char seconds;
+  unsigned char minutes;
+  unsigned char hours;
+  unsigned char dayofweek;
+  unsigned char date;
+  unsigned char month;
+  unsigned char year;
+} DS1305_DATETIME;
+
+/* set/get the current time/date passed the address of a DS1305_DATETIME struct
+   To set the current time/date to "20:11:32 Sunday 29/07/2009"
+   DS1305_DATETIME current = {0x32, 0x11, 0x20, 0x01, 0x29, 0x05, 0x09};
+   set_time(&current);
+*/
+#define set_time(datetime) ds1305_write_block(DS1305_TIME, (unsigned char *)datetime, 7)
+#define get_time(datetime)  ds1305_read_block(DS1305_TIME, (unsigned char *)datetime, 7)
+
+/* set/get the time of alarm0/alarm1 passed the address of a DS1305_DATETIME struct,
+   although only the seconds/minutes/hours/dayofweek are sent/received
+*/
+#define set_alarm0(time) ds1305_write_block(DS1305_ALARM0, (unsigned char *)time, 4)
+#define get_alarm0(time)  ds1305_read_block(DS1305_ALARM0, (unsigned char *)time, 4)
+#define set_alarm1(time) ds1305_write_block(DS1305_ALARM1, (unsigned char *)time, 4)
+#define get_alarm1(time)  ds1305_read_block(DS1305_ALARM1, (unsigned char *)time, 4)
+
+// flags used in set_control/get_control
+#define DS1305_EOSC  0x80 // enable oscillator, note this is inverse of ^EOSC bit value on chip
+#define DS1305_WP 0x40    // write protect
+#define DS1305_INTCN 0x04 // enable interrupts
+#define DS1305_AIE1 0x02  // alarm0 interrupt enable
+#define DS1305_AIE0 0x01  // alarm1 interrupt enable
+
+/* get/set the control register.  To enable  the oscillator, turn on write protection 
+   and enable all interrupts the following would be used:
+   set_control(DS1305_EOSC | DS1305_WP | DS1305_INTCN | DS1305_AIE1 | DS1305_AIE0);
+*/
+#define set_control(data) ds1305_transfer(DS1305_CONTROL+DS1305_WRITE, (data) ^ DS1305_EOSC)
+#define get_control(data) (ds1305_transfer(DS1305_CONTROL, 0xFF) ^ DS1305_EOSC)
+
+// flags used in get_status
+#define DS1305_IRQF0 0x01 // interrupt 0 request flag - current time has matched alarm 0
+#define DS1305_IRQF1 0x02 // interrupt 1 request flag - current time has matched alarm 1
+#define get_status(data) ds1305_transfer(DS1305_STATUS, 0xFF)
+
+// flags used in set_charger/get_charger
+#define DS1305_CHARGER_OFF 0x5C // no charge - don't combine with other values
+#define DS1305_CHARGER_1D2K 0xA5 // 1 diode 2K resistor
+#define DS1305_CHARGER_1D4K 0xA6 // 1 diode 4K resistor
+#define DS1305_CHARGER_1D8K 0xA7 // 1 diode 8K resistor
+#define DS1305_CHARGER_2D2K 0xA1 // 2 diode 2K resistor
+#define DS1305_CHARGER_2D4K 0xA2 // 2 diode 4K resistor
+#define DS1305_CHARGER_2D8K 0xA3 // 2 diode 8K resistor
+/* get/set the charger register */
+#define set_charger(data) ds1305_transfer(DS1305_CHARGE+DS1305_WRITE, data)
+#define get_charger(data) ds1305_transfer(DS1305_CHARGE, 0xFF)
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif
@@ -0,0 +1,53 @@
+#######################################
+# Syntax Coloring Map For SPI
+#######################################
+
+#######################################
+# Datatypes (KEYWORD1)
+#######################################
+DS1305_DATETIME	KEYWORD1
+
+#######################################
+# Methods and Functions (KEYWORD2)
+#######################################
+
+select_ds1305	KEYWORD2
+deselect_ds1305	KEYWORD2
+set_time	KEYWORD2
+get_time	KEYWORD2
+set_control	KEYWORD2
+get_control	KEYWORD2
+set_charger	KEYWORD2
+get_charger	KEYWORD2
+get_alarm0	KEYWORD2
+set_alarm1	KEYWORD2
+get_alarm1	KEYWORD2
+get_status	KEYWORD2
+
+#######################################
+# Constants 	KEYWORD2
+#######################################
+DS1305_WRITE	LITERAL1
+DS1305_TIME	LITERAL1
+DS1305_ALARM0	LITERAL1
+DS1305_ALARM1	LITERAL1
+DS1305_CONTROL	LITERAL1
+DS1305_STATUS	LITERAL1
+DS1305_CHARGER	LITERAL1
+DS1305_USERRAM	LITERAL1
+DS1305_ALARM_SET	LITERAL1
+DS1305_EOSC	LITERAL1
+DS1305_WP	LITERAL1
+DS1305_INTCN	LITERAL1
+DS1305_AIE1	LITERAL1
+DS1305_AIE0	LITERAL1
+DS1305_IRQF0	LITERAL1
+DS1305_IRQF1	LITERAL1
+DS1305_CHARGER_OFF	LITERAL1
+DS1305_CHARGER_1D2K	LITERAL1
+DS1305_CHARGER_1D4K	LITERAL1
+DS1305_CHARGER_1D8K	LITERAL1
+DS1305_CHARGER_2D2K	LITERAL1
+DS1305_CHARGER_2D4K	LITERAL1
+DS1305_CHARGER_2D8K	LITERAL1
+
@@ -0,0 +1,79 @@
+#include <spi.h>
+#include <ds1305.h>
+
+#define DS1305_PIN 4
+#define LED_PIN 3
+
+// following two methods required by DS1305 library to select/deselect device
+void select_ds1305(void)
+{
+  digitalWrite(DS1305_PIN, HIGH);
+}
+
+void deselect_ds1305(void)
+{
+  digitalWrite(DS1305_PIN, LOW);
+}
+
+// flash led that's connected to pin 3
+void flash_led(void)
+{
+  pinMode(LED_PIN, OUTPUT);
+  for (int i=0; i<10; i++) {
+    digitalWrite(LED_PIN, i%2==0);
+    delay(50);
+  }
+}
+
+// called when pin INT0 goes from 1 to 0
+ISR(INT0_vect)
+{
+  // get alarm value to clear alarm interrupt flag on DS1305
+  DS1305_DATETIME alarm;
+  get_alarm0(&alarm);
+  flash_led();
+}
+
+void setup()
+{
+  // flash LED at start to indicate were about to start
+  flash_led();
+  flash_led();
+  
+  // pin used to enable DS1305
+  pinMode(DS1305_PIN, OUTPUT);
+
+  // Make sure ADC is unselected and setup spi
+  deselect_ds1305();
+  setup_spi(SPI_MODE_1, SPI_MSB, SPI_NO_INTERRUPT, SPI_MSTR_CLK16);
+  set_control(0);
+
+  // set current date/time to Thursday 06/05/09 20:32:30
+  DS1305_DATETIME current = {0x30, 0x32, 0x20, 0x05, 0x06, 0x05, 0x09};
+  set_time(&current);
+  
+  // change the value of alarm to the required time/granularity:
+  // raise alarm every day (at 20:32:00):
+  // DS1305_DATETIME alarm = {0x00, 0x32, 0x20, 0x00 | DS1305_ALARM_SET};
+  // raise alarm every minute (when seconds = 00):
+  // DS1305_DATETIME alarm = {0x00, 0x32 | DS1305_ALARM_SET,
+  //		   0x20 | DS1305_ALARM_SET, 0x05 | DS1305_ALARM_SET};
+  // raise alarm every second:
+  DS1305_DATETIME alarm = {0x55 | DS1305_ALARM_SET, 0x32 | DS1305_ALARM_SET,
+			   0x20 | DS1305_ALARM_SET, 0x05 | DS1305_ALARM_SET};
+  set_alarm0(&alarm);
+  // turn on timer and make alarm0 lower INT0 pin when alarm is triggered
+  set_control(DS1305_EOSC | DS1305_INTCN | DS1305_AIE0);
+
+  // raise interrupt when INT0 pin falls (pin PD0 at AT90usbXXX, pin PD2 on ATmegaXXX (arduino pin 2))
+  // the code in ISR(INT0_vect) above will be called
+  EICRA = (1<<ISC01) | (0<<ISC00);
+  // enable interrupts
+  EIMSK = (1<<INT0);
+  sei();
+}
+
+void loop()
+{
+  // do nothing - all action happens in interrupt
+}
@@ -0,0 +1,38 @@
+#include <spi.h>
+
+// MAX6675 connected to pin D9
+#define MAX6675_SELECT_PIN 8
+#define DESELECT_MAX6675 digitalWrite(MAX6675_SELECT_PIN, HIGH)
+#define SELECT_MAX6675 digitalWrite(MAX6675_SELECT_PIN, LOW)
+
+void setup()
+{
+  pinMode(MAX6675_SELECT_PIN, OUTPUT);
+  DESELECT_MAX6675;
+  setup_spi(SPI_MODE_1, SPI_MSB, SPI_NO_INTERRUPT, SPI_MSTR_CLK8);
+  Serial.begin(19200);
+}
+
+void loop()
+{
+  delay(500);
+
+  // select the device, wait > 100nS, read two bytes, deselect
+  SELECT_MAX6675;
+  delayMicroseconds(1);
+  unsigned char highByte = send_spi(0);
+  unsigned char lowByte = send_spi(0);
+  DESELECT_MAX6675;
+  
+  // if bit 3 is high thermocouple is unconnected
+  if (lowByte & (1<<2)) {
+    Serial.print("Not connected "); 
+    Serial.print(highByte, HEX); Serial.print(" ");
+    Serial.println(lowByte, HEX);
+  } else {
+    // temperature value is in bits 6-0 of highByte and 7-2 of lowByte
+    short value = (highByte << 5 | lowByte>>3);
+    // 1 bit is 0.25 degree 'divide' by 4 to show degrees
+    Serial.print(value/4); Serial.print("."); Serial.println(value%4 *25);
+  }
+}
@@ -0,0 +1,32 @@
+#include <spi.h>
+
+#define SELECT_ADC digitalWrite(8, LOW);
+#define DESELECT_ADC  digitalWrite(8, HIGH);
+
+unsigned short read_adc(void)
+{
+  // select ADC wait 100microseconds then read two bytes
+  SELECT_ADC;
+  unsigned char one = send_spi(0xFF);
+  unsigned char two = send_spi(0xFF);
+  DESELECT_ADC;
+  // 12 bits of ADC value is bottom 5 bits of first
+  // byte and top 7 bits of second, move into 16 bit int
+  return ((0x1F & one) << 7) | (two >> 1);
+}
+
+void setup()
+{
+  pinMode(8, OUTPUT);
+  Serial.begin(19200);
+  // make sure ADC is not selected and setup spi
+  DESELECT_ADC;
+  setup_spi(SPI_MODE_0, SPI_MSB, SPI_NO_INTERRUPT, SPI_MSTR_CLK16);
+}
+
+void loop()
+{
+  unsigned short num = read_adc();
+  Serial.println(num);
+  delay(1000);
+}
@@ -0,0 +1,91 @@
+#include <spi.h>
+#include <util/delay.h>
+
+#define BUTTON_PIN 2
+#define LED_PIN 3
+#define FLASH_LED_COMMAND 0x01
+
+#define OTHER_SELECT_PIN 7
+#define SELECT_OTHER digitalWrite(OTHER_SELECT_PIN, LOW);
+#define DESELECT_OTHER digitalWrite(OTHER_SELECT_PIN, HIGH);
+
+#define BUFSIZE 20
+volatile unsigned char incoming[BUFSIZE];
+volatile short int received=0;
+
+// flash led that's connected to pin PD7
+void flash_led(int count)
+{
+  pinMode(LED_PIN, OUTPUT);
+  for (int i=0; i<count*2; i++) {
+    digitalWrite(LED_PIN, i%2==0);
+    _delay_ms(75);
+  }
+}
+
+// send a SPI message to the other device - 3 bytes then go back into 
+// slave mode
+void send_message()
+{
+  setup_spi(SPI_MODE_1, SPI_MSB, SPI_NO_INTERRUPT, SPI_MSTR_CLK8);
+  if (SPCR & (1<<MSTR)) { // if we are still in master mode
+    SELECT_OTHER; // tell other device to flash LED twice
+    send_spi(FLASH_LED_COMMAND); send_spi(0x02); send_spi(0x00);
+    DESELECT_OTHER;
+  }
+  setup_spi(SPI_MODE_1, SPI_MSB, SPI_INTERRUPT, SPI_SLAVE);
+}
+
+
+// called when button pushed and pin INT0 goes from 1 to 0
+void button_pressed()
+{
+  send_message();
+  _delay_ms(500);  // 'debounce'
+}
+
+// parse the data received from the other device
+// currently just knows about the FLASH_LED_COMMAND
+void parse_message()
+{
+  switch(incoming[0]) {
+  case FLASH_LED_COMMAND:
+    flash_led(incoming[1]);
+    break;
+  default:
+    flash_led(20);
+  }
+}
+
+// called by the SPI system when there is data ready.
+// Just store the incoming data in a buffer, when we receive a
+// terminating byte (0x00) call parse_message to process the data received
+ISR(SPI_STC_vect)
+{
+  incoming[received++] = received_from_spi(0x00);
+  if (received == BUFSIZE || incoming[received-1] == 0x00) {
+      parse_message();
+      received = 0;
+   }
+}
+
+void setup()
+{
+  // make sure other device is unselected (pin is HIGH) and setup spi
+  DESELECT_OTHER;
+  pinMode(OTHER_SELECT_PIN, OUTPUT);
+  setup_spi(SPI_MODE_1, SPI_MSB, SPI_INTERRUPT, SPI_SLAVE);
+
+  // raise interrupt when INT0 pin falls (arduino pin 2))
+  // the function button_pressed will be called
+  attachInterrupt(0, button_pressed, FALLING);
+
+  // flash LED at start to indicate were ready
+  flash_led(1);
+}
+
+
+void loop()
+{
+  // do nothing
+}
@@ -0,0 +1,62 @@
+/**
+* First stab at a test suite for spi lib.
+*/
+#include <spi.h>
+
+void reportError(int line, char *message, uint8_t expected, uint8_t actual)
+{
+  Serial.print("Test "); Serial.print(message);
+  Serial.print(" failed at line "); Serial.print(line-3);
+  Serial.print(", expected="); Serial.print(expected, BIN);
+  Serial.print(", actual="); Serial.println(actual, BIN);
+}
+
+#define assertEquals(message, expected, actual) \
+  if (expected != actual) { reportError(__LINE__, message, expected, actual); return; }
+
+
+#define test_setup_spi(message, eSPCR, eSPSR, mode, dord, interrupt, clock) \
+    setup_spi(mode, dord, interrupt, clock); \
+    assertEquals(message, eSPCR, SPCR); \
+    assertEquals(message, eSPSR, SPSR & 0x01);
+
+
+void test_registers()
+{
+  // top 4 bits of SPCR - enabled, interrupt, lsb/msb, master/slave
+  disable_spi();
+  assertEquals("0", 0x00, SPCR);
+  
+  test_setup_spi("1", 0xE0, 0x00, SPI_MODE_0, SPI_LSB, SPI_INTERRUPT, SPI_SLAVE);
+  test_setup_spi("2", 0x60, 0x00, SPI_MODE_0, SPI_LSB, SPI_NO_INTERRUPT, SPI_SLAVE);
+  test_setup_spi("3", 0x40, 0x00, SPI_MODE_0, SPI_MSB, SPI_NO_INTERRUPT, SPI_SLAVE);
+
+  // CPOL/CPHA bits - timing mode
+  test_setup_spi("4", 0x40, 0x00, SPI_MODE_0, SPI_MSB, SPI_NO_INTERRUPT, SPI_SLAVE);
+  test_setup_spi("5", 0x44, 0x00, SPI_MODE_1, SPI_MSB, SPI_NO_INTERRUPT, SPI_SLAVE);
+  test_setup_spi("6", 0x48, 0x00, SPI_MODE_2, SPI_MSB, SPI_NO_INTERRUPT, SPI_SLAVE);
+  test_setup_spi("7", 0x4C, 0x00, SPI_MODE_3, SPI_MSB, SPI_NO_INTERRUPT, SPI_SLAVE);
+
+  // clock 
+  test_setup_spi("9", 0xE0, 1, SPI_MODE_0, SPI_LSB, SPI_INTERRUPT, SPI_MSTR_CLK2);
+  test_setup_spi("10", 0xE0, 0, SPI_MODE_0, SPI_LSB, SPI_INTERRUPT, SPI_MSTR_CLK4);
+  test_setup_spi("11", 0xE1, 1, SPI_MODE_0, SPI_LSB, SPI_INTERRUPT, SPI_MSTR_CLK8);
+  test_setup_spi("12", 0xE1, 0, SPI_MODE_0, SPI_LSB, SPI_INTERRUPT, SPI_MSTR_CLK16);
+  test_setup_spi("13", 0xE2, 1, SPI_MODE_0, SPI_LSB, SPI_INTERRUPT, SPI_MSTR_CLK32);
+  test_setup_spi("14", 0xE2, 0, SPI_MODE_0, SPI_LSB, SPI_INTERRUPT, SPI_MSTR_CLK64);
+  test_setup_spi("15", 0xE3, 0, SPI_MODE_0, SPI_LSB, SPI_INTERRUPT, SPI_MSTR_CLK128);
+}
+ 
+void setup()
+{
+  Serial.begin(19200);
+}
+
+void loop()
+{
+  delay(5000);
+  Serial.println("Running tests");
+  test_registers();
+  Serial.println("Run tests");
+  while(true);
+}
@@ -0,0 +1,39 @@
+#######################################
+# Syntax Coloring Map For SPI
+#######################################
+
+#######################################
+# Datatypes (KEYWORD1)
+#######################################
+
+#######################################
+# Methods and Functions (KEYWORD2)
+#######################################
+
+setup_spi	KEYWORD2
+disable_spi	KEYWORD2
+send_spi	KEYWORD2 
+
+#######################################
+# Constants (LITERAL1)
+#######################################
+SPI_SS_PIN	LITERAL1
+SPI_SCK_PIN	LITERAL1
+SPI_MOSI_PIN	LITERAL1
+SPI_MISO_PIN	LITERAL1
+SPI_MODE_0	LITERAL1
+SPI_MODE_1	LITERAL1
+SPI_MODE_2	LITERAL1
+SPI_MODE_3	LITERAL1
+SPI_LSB	LITERAL1
+SPI_MSB	LITERAL1
+SPI_NO_INTERRUPT	LITERAL1
+SPI_INTERRUPT	LITERAL1
+SPI_SLAVE	LITERAL1
+SPI_MSTR_CLK2	LITERAL1
+SPI_MSTR_CLK4	LITERAL1
+SPI_MSTR_CLK8	LITERAL1
+SPI_MSTR_CLK16	LITERAL1
+SPI_MSTR_CLK32	LITERAL1
+SPI_MSTR_CLK64	LITERAL1
+SPI_MSTR_CLK128	LITERAL1
@@ -0,0 +1,74 @@
+/* 
+ * Copyright (c) 2009 Andrew Smallbone <andrew@rocketnumbernine.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <spi.h>
+
+#ifdef __cplusplus
+extern "C"{
+#endif
+
+#ifdef __ARDUINO__
+#include <wiring.h>
+#endif
+
+void setup_spi(uint8_t mode, int dord, int interrupt, uint8_t clock)
+{
+  // specify pin directions for SPI pins on port B
+  if (clock == SPI_SLAVE) { // if slave SS and SCK is input
+    DDRB &= ~(1<<SPI_MOSI_PIN); // input
+    DDRB |= (1<<SPI_MISO_PIN); // output
+    DDRB &= ~(1<<SPI_SS_PIN); // input
+    DDRB &= ~(1<<SPI_SCK_PIN);// input
+  } else {
+    DDRB |= (1<<SPI_MOSI_PIN); // output
+    DDRB &= ~(1<<SPI_MISO_PIN); // input
+    DDRB |= (1<<SPI_SCK_PIN);// output
+    DDRB |= (1<<SPI_SS_PIN);// output
+  }
+  SPCR = ((interrupt ? 1 : 0)<<SPIE) // interrupt enabled
+    | (1<<SPE) // enable SPI
+    | (dord<<DORD) // LSB or MSB
+    | (((clock != SPI_SLAVE) ? 1 : 0) <<MSTR) // Slave or Master
+    | (((mode & 0x02) == 2) << CPOL) // clock timing mode CPOL
+    | (((mode & 0x01)) << CPHA) // clock timing mode CPHA
+    | (((clock & 0x02) == 2) << SPR1) // cpu clock divisor SPR1
+    | ((clock & 0x01) << SPR0); // cpu clock divisor SPR0
+  SPSR = (((clock & 0x04) == 4) << SPI2X); // clock divisor SPI2X
+}
+
+void disable_spi()
+{
+  SPCR = 0;
+}
+
+uint8_t send_spi(uint8_t out)
+{
+  SPDR = out;
+  while (!(SPSR & (1<<SPIF)));
+  return SPDR;
+}
+
+uint8_t received_from_spi(uint8_t data)
+{
+  SPDR = data;
+  return SPDR;
+}
@@ -0,0 +1,94 @@
+/* 
+ * Copyright (c) 2009 Andrew Smallbone <andrew@rocketnumbernine.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef _spi_h__
+#define _spi_h__
+
+#include <avr/io.h>
+
+#ifdef __cplusplus
+extern "C"{
+#endif
+
+// create alias for the different SPI chip pins - code assumes all on port B
+#if (defined(__AVR_AT90USB82__) || defined(__AVR_AT90USB162__))
+ #define SPI_SS_PIN PORTB0
+ #define SPI_SCK_PIN PORTB1
+ #define SPI_MOSI_PIN PORTB2
+ #define SPI_MISO_PIN PORTB3
+#elif (defined(__AVR_ATmega48__) || defined(_AVR_ATmega88__) || defined(__AVR_ATmega168__) || defined(__AVR_ATmega328__) || defined(__AVR_ATmega328P__))
+ #define SPI_SS_PIN PORTB2
+ #define SPI_SCK_PIN PORTB5
+ #define SPI_MOSI_PIN PORTB3
+ #define SPI_MISO_PIN PORTB4
+#else
+ #error unknown processor - add to spi.h
+#endif
+
+// SPI clock modes
+#define SPI_MODE_0 0x00 /* Sample (Rising) Setup (Falling) CPOL=0, CPHA=0 */
+#define SPI_MODE_1 0x01 /* Setup (Rising) Sample (Falling) CPOL=0, CPHA=1 */
+#define SPI_MODE_2 0x02 /* Sample (Falling) Setup (Rising) CPOL=1, CPHA=0 */
+#define SPI_MODE_3 0x03 /* Setup (Falling) Sample (Rising) CPOL=1, CPHA=1 */
+
+// data direction
+#define SPI_LSB 1 /* send least significant bit (bit 0) first */
+#define SPI_MSB 0 /* send most significant bit (bit 7) first */
+
+// whether to raise interrupt when data received (SPIF bit received)
+#define SPI_NO_INTERRUPT 0
+#define SPI_INTERRUPT 1
+
+// slave or master with clock diviser
+#define SPI_SLAVE 0xF0
+#define SPI_MSTR_CLK4 0x00 /* chip clock/4 */
+#define SPI_MSTR_CLK16 0x01 /* chip clock/16 */
+#define SPI_MSTR_CLK64 0x02 /* chip clock/64 */
+#define SPI_MSTR_CLK128 0x03 /* chip clock/128 */
+#define SPI_MSTR_CLK2 0x04 /* chip clock/2 */
+#define SPI_MSTR_CLK8 0x05 /* chip clock/8 */
+#define SPI_MSTR_CLK32 0x06 /* chip clock/32 */
+
+
+
+// setup spi
+void setup_spi(uint8_t mode,   // timing mode SPI_MODE[0-4]
+	       int dord,             // data direction SPI_LSB|SPI_MSB
+	       int interrupt,        // whether to raise interrupt on recieve
+	       uint8_t clock); // clock diviser
+
+// disable spi
+void disable_spi(void);
+
+// send and receive a byte of data (master mode)
+uint8_t send_spi(uint8_t out);
+
+// receive the byte of data waiting on the SPI buffer and
+// set the next byte to transfer - for use in slave mode
+// when interrupts are enabled.
+uint8_t received_from_spi(uint8_t out);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif
+
@@ -0,0 +1,17 @@
+# -*- makefile -*-
+
+#TARGET = spi-test-adc
+#TARGET = spi-test-rtc
+TARGET = spi-test-masterslave
+
+OBJECTS = $(TARGET).o spi.o
+CFLAGS = -I../libs
+include ./Makefile.mf
+
+DEVICE     = at90usb162
+CLOCK      = 16000000
+
+examples:
+	make -k TARGET=spi-test-adc clean all
+	make -k TARGET=spi-test-rtc OBJECTS="spi-test-rtc.o spi.o ds1305.o" clean all
+	make -k TARGET=spi-test-masterslave clean all
@@ -0,0 +1,109 @@
+# Name: Makefile
+
+# 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.
+# FUSES ........ Parameters for avrdude to flash the fuses appropriately.
+
+DEVICE     = at90usb162
+CLOCK      = 16000000
+PROGRAMMER = -c stk500v2 -P avrdoper
+#OBJECTS    = $(TARGET).o
+FUSES      = -U hfuse:w:0xd9:m -U lfuse:w:0x24:m
+# ATMega8 fuse bits (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)
+
+# Example for 12 MHz external crystal:
+# Fuse high byte:
+# 0xc9 = 1 1 0 0   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:
+# 0x9f = 1 0 0 1   1 1 1 1
+#        ^ ^ \ /   \--+--/
+#        | |  |       +------- CKSEL 3..0 (external >8M crystal)
+#        | |  +--------------- SUT 1..0 (crystal osc, BOD enabled)
+#        | +------------------ BODEN (if 0, brown-out detector is enabled)
+#        +-------------------- BODLEVEL (if 0: 4V, if 1: 2.7V)
+
+
+# Tune the lines below only if you know what you are doing:
+
+AVRDUDE = avrdude $(PROGRAMMER) -p $(DEVICE)
+COMPILE = avr-gcc $(CFLAGS) -Wall -std=gnu99 -funsigned-char -funsigned-bitfields -ffunction-sections -fpack-struct -fshort-enums -I. -Os -DF_CPU=$(CLOCK) -mmcu=$(DEVICE)
+
+# symbolic targets:
+all:	$(TARGET).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
+	$(AVRDUDE) -U flash:w:$(TARGET).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 $(TARGET).hex
+
+clean:
+	rm -f $(TARGET).hex $(TARGET).elf $(OBJECTS)
+
+# file targets:
+$(TARGET).elf: $(OBJECTS)
+	$(COMPILE) -o $(TARGET).elf $(OBJECTS)
+
+$(TARGET).hex: $(TARGET).elf
+	rm -f $(TARGET).hex
+	avr-objcopy -j .text -j .data -O ihex $(TARGET).elf $(TARGET).hex
+# 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:	$(TARGET).elf
+	avr-objdump -d $(TARGET).elf
+
+cpp:
+	$(COMPILE) -E $(TARGET).c
@@ -0,0 +1,63 @@
+/* 
+ * Copyright (c) 2009 Andrew Smallbone <andrew@rocketnumbernine.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <ds1305.h>
+
+#ifdef __cplusplus
+extern "C"{
+#endif
+
+unsigned char ds1305_transfer(unsigned char address, unsigned char data)
+{
+  select_ds1305();
+  send_spi(address);
+  unsigned char out = send_spi(data);
+  deselect_ds1305();
+  return out;
+}
+
+void ds1305_write_block(unsigned char address, unsigned char *data, int length)
+{
+  select_ds1305();
+  send_spi(address+DS1305_WRITE);
+  int i;
+  for (i=0; i<length; i++) {
+    send_spi(*data++);
+  }
+  deselect_ds1305();
+}
+
+void ds1305_read_block(unsigned char address, unsigned char *data, int length)
+{
+  select_ds1305();
+  send_spi(address);
+  int i;
+  for (i=0; i<length; i++) {
+    *(data+i) = send_spi(0xFF);
+  }
+  deselect_ds1305();
+}
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
@@ -0,0 +1,115 @@
+/* 
+ * Copyright (c) 2009 Andrew Smallbone <andrew@rocketnumbernine.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef _ds1305_h__
+#define _ds1305_h__
+
+#include <spi.h>
+
+#ifdef __cplusplus
+extern "C"{
+#endif
+
+// these should be defined to the operation used to select/deselect the DS1305
+void select_ds1305(void);
+void deselect_ds1305(void);
+
+#define DS1305_WRITE 0x80
+#define DS1305_TIME 0x00
+#define DS1305_ALARM0 0x07
+#define DS1305_ALARM1 0x0B
+#define DS1305_CONTROL 0x0F
+#define DS1305_STATUS 0x010
+#define DS1305_CHARGER 0x11
+#define DS1305_USERRAM 0x20
+
+#define DS1305_ALARM_SET 0x80
+
+// send the address and a byte and returns the byte returned by the DS1305
+unsigned char ds1305_transfer(unsigned char address, unsigned char data);
+// write a block of bytes - will add 0x80 to the address
+void ds1305_write_block(unsigned char address, unsigned char *data, int length);
+// read a block of bytes
+void ds1305_read_block(unsigned char address, unsigned char *data, int length);
+
+typedef struct _DS1305_DATETIME
+{
+  unsigned char seconds;
+  unsigned char minutes;
+  unsigned char hours;
+  unsigned char dayofweek;
+  unsigned char date;
+  unsigned char month;
+  unsigned char year;
+} DS1305_DATETIME;
+
+/* set/get the current time/date passed the address of a DS1305_DATETIME struct
+   To set the current time/date to "20:11:32 Sunday 29/07/2009"
+   DS1305_DATETIME current = {0x32, 0x11, 0x20, 0x01, 0x29, 0x05, 0x09};
+   set_time(&current);
+*/
+#define set_time(datetime) ds1305_write_block(DS1305_TIME, (unsigned char *)datetime, 7)
+#define get_time(datetime)  ds1305_read_block(DS1305_TIME, (unsigned char *)datetime, 7)
+
+/* set/get the time of alarm0/alarm1 passed the address of a DS1305_DATETIME struct,
+   although only the seconds/minutes/hours/dayofweek are sent/received
+*/
+#define set_alarm0(time) ds1305_write_block(DS1305_ALARM0, (unsigned char *)time, 4)
+#define get_alarm0(time)  ds1305_read_block(DS1305_ALARM0, (unsigned char *)time, 4)
+#define set_alarm1(time) ds1305_write_block(DS1305_ALARM1, (unsigned char *)time, 4)
+#define get_alarm1(time)  ds1305_read_block(DS1305_ALARM1, (unsigned char *)time, 4)
+
+// flags used in set_control/get_control
+#define DS1305_EOSC  0x80 // enable oscillator, note this is inverse of ^EOSC bit value on chip
+#define DS1305_WP 0x40    // write protect
+#define DS1305_INTCN 0x04 // enable interrupts
+#define DS1305_AIE1 0x02  // alarm0 interrupt enable
+#define DS1305_AIE0 0x01  // alarm1 interrupt enable
+
+/* get/set the control register.  To enable  the oscillator, turn on write protection 
+   and enable all interrupts the following would be used:
+   set_control(DS1305_EOSC | DS1305_WP | DS1305_INTCN | DS1305_AIE1 | DS1305_AIE0);
+*/
+#define set_control(data) ds1305_transfer(DS1305_CONTROL+DS1305_WRITE, (data) ^ DS1305_EOSC)
+#define get_control(data) (ds1305_transfer(DS1305_CONTROL, 0xFF) ^ DS1305_EOSC)
+
+// flags used in get_status
+#define DS1305_IRQF0 0x01 // interrupt 0 request flag - current time has matched alarm 0
+#define DS1305_IRQF1 0x02 // interrupt 1 request flag - current time has matched alarm 1
+#define get_status(data) ds1305_transfer(DS1305_STATUS, 0xFF)
+
+// flags used in set_charger/get_charger
+#define DS1305_CHARGER_OFF 0x5C // no charge - don't combine with other values
+#define DS1305_CHARGER_1D2K 0xA5 // 1 diode 2K resistor
+#define DS1305_CHARGER_1D4K 0xA6 // 1 diode 4K resistor
+#define DS1305_CHARGER_1D8K 0xA7 // 1 diode 8K resistor
+#define DS1305_CHARGER_2D2K 0xA1 // 2 diode 2K resistor
+#define DS1305_CHARGER_2D4K 0xA2 // 2 diode 4K resistor
+#define DS1305_CHARGER_2D8K 0xA3 // 2 diode 8K resistor
+/* get/set the charger register */
+#define set_charger(data) ds1305_transfer(DS1305_CHARGE+DS1305_WRITE, data)
+#define get_charger(data) ds1305_transfer(DS1305_CHARGE, 0xFF)
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif
@@ -0,0 +1,111 @@
+This directory contains a simple AVR spi helper library that should
+run on most AVR microcontrollers which support SPI.
+
+The code is further described at:
+http://www.rocketnumbernine.com/2009/04/26/using-spi-on-an-avr-1/ (basics & ADC)
+http://www.rocketnumbernine.com/2009/05/12/using-spi-on-an-avr-2/ (RTC)
+
+Any comments/questions to <andrew@rocketnumbernine.com>
+
+Make sure viewing this text in a fixed width font for the tables and diagrams
+
+
+----------------------------------
+Arduino
+----------------------------------
+The Arduino Directory contains all code required to run on the Arduino.
+Simply copy the Arduino/SPI and Arduino/DS1305 directories to the 
+"hardware/libraries" directory of your Arduino IDE installation and
+restart the Arduino IDE. Once restarted there should be
+"Sketch->Import Library->SPI" and "Sketch->Import Library->DS1305" menu
+entries which can be used to include the spi header files into your project.
+"File->Sketchbook->Examples->Library SPI" contains 3 example projects
+
+
+----------------------------------
+AVR GCC
+----------------------------------
+To use, just copy spi.h and spi.c (and ds1305.c and ds1305.h if using
+the DS1305 Real Time Clock chip) to your own project and compile.
+
+Makefile.mf - 'standard' generated make file from AVR GCC
+Makefile - Makefile "make examples" will make example programs below:
+
+spi-test-adc.c        MC3201 Analogue to Digital convertor example
+spi-test-rtc.c        DS1305 - Real-Time-Clock/Alarm example
+spi-test-masterslave.c        Master/Slave communication example
+
+
+----------------------------------
+PINS
+----------------------------------
+Following are the AVR pins used in the circuits below
+
+      ATmegaXXX  Arduino AT90usbXXX
+MISO    PB4        12       PB3
+MOSI    PB3        11       PB2
+SCK     PB5        13       PB1
+SS      PB2        10       PB0
+
+INT0    PD2         2       PD0   
+
+
+----------------------------------
+MC3201 12-bit ADC Circuit
+----------------------------------
+See http://ww1.microchip.com/downloads/en/DeviceDoc/21290D.pdf for full details.
+
+             +-----------------+
+             |     MC3201      |
+        +5V [| Vref        Vdd |] +5V
+             |                 |
+Analogue In [| IN+         CLK |] AVR SCK
+             |                 |
+     Ground [| IN-        Dout |] AVR MOSI
+             |                 |
+     Ground [| Vss         ^CS |] AVR CE
+             +-----------------+
+
+
+For testing purposes "Analogue In" can be connected to the middle wire
+of a potentiometer with one outer wire being connected to +5 and the
+other to Ground.  A 1uF Capacitor should be placed between the analogue
+input and ground, and +5V and ground as close to the chip as possible,
+but in a pinch the circuit will likely work without.
+
+
+MOSI/SLCK/CE to the relevant pin on the AVR (MISO is not used) - see above.
+
+----------------------------------
+DS1305 Real Time Clock Circuit
+----------------------------------
+See http://datasheets.maxim-ic.com/en/ds/DS1305.pdf for full details.
+
+Without a battery the following connections can be used:
+
+                +-----------------+
+                |      DS1305     |
+       Ground  [| Vcc2       Vcc1 |] +5V
+                |                 |
+       Ground  [| Vbat        ^PF |] Not Connected
+                |                 |
+       Crystal [| X1        Vccif |] +5V
+                |                 |
+       Crystal [| X2          SDO |] AVR MISO
+                |                 |
+ Not Connected [| N.C.        SDI |] AVR MOSI
+                |                 |
+      AVR INT0 [| INT0       SLCK |] AVR SLCK
+                |                 |
+ Not Connected [| INT1        CE  |] AVR CE
+                |                 |
+        Ground [| GND     SERMODE |] +5V
+                +-----------------+
+
+
+MISO/MOSI/SLCK/CE/INT0 to the relevant pin on the AVR - see above.
+
+
+
+
+
@@ -0,0 +1,61 @@
+/* 
+ * Copyright (c) 2009 Andrew Smallbone <andrew@rocketnumbernine.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <avr/io.h>
+#include <util/delay.h>
+#include <spi.h>
+
+#define SELECT_ADC PORTB &= ~(1<<PB4)
+#define DESELECT_ADC PORTB |= (1<<PB4)
+
+unsigned short read_adc(void)
+{
+  // select ADC wait 100 microseconds then read two bytes
+  SELECT_ADC;
+  _delay_us(100);
+  unsigned char one = send_spi(0xFF);
+  _delay_us(100);
+  unsigned char two = send_spi(0xFF);
+  DESELECT_ADC;
+  // 12 bits of ADC value is bottom 5 bits of first
+  // byte and top 7 bits of second, move into 16 bit int
+  return ((0x1F & one) << 7) | (two >> 1);
+}
+
+int main(void)
+{
+  DDRB |= (1<<PB4); // chip select for ADC
+  // use port D for leds
+  DDRD = 0xFF;
+  PORTD = 0x00;
+
+  // make sure ADC is unselected and setup spi
+  SELECT_ADC;
+  setup_spi(SPI_MODE_0, SPI_MSB, SPI_NO_INTERRUPT, SPI_MSTR_CLK16);
+
+  while (1) {
+    unsigned int num = read_adc();
+    PORTD = (1<< (num >> 9)); // use the top 3 bytes to turn on LED
+    _delay_ms(1);
+  }  
+}
+
@@ -0,0 +1,88 @@
+#include <avr/interrupt.h>
+#include <util/delay.h>
+#include <spi.h>
+
+#define FLASH_LED_COMMAND 0x01
+#define OTHER_SELECT_PIN PB6
+#define SELECT_OTHER PORTB &= ~(1<<OTHER_SELECT_PIN)
+#define DESELECT_OTHER PORTB |= (1<<OTHER_SELECT_PIN)
+
+#define BUFSIZE 20
+volatile unsigned char incoming[BUFSIZE];
+volatile short int received=0;
+
+
+// flash led that's connected to pin PD7
+void flash_led(int count)
+{
+  DDRD |= (1<<PD7);
+  for (int i=0; i<count*2; i++) {
+    PORTD ^= (1<<PD7);
+    _delay_ms(75);
+  }
+}
+
+// send a SPI message to the other device - 3 bytes then go back into 
+// slave mode
+void send_message()
+{
+  setup_spi(SPI_MODE_1, SPI_MSB, SPI_NO_INTERRUPT, SPI_MSTR_CLK8);
+  if (SPCR & (1<<MSTR)) { // if we are still in master mode
+    SELECT_OTHER; // tell other device to flash LED twice
+    send_spi(FLASH_LED_COMMAND); send_spi(0x02); send_spi(0x00);
+    DESELECT_OTHER;
+  }
+  setup_spi(SPI_MODE_1, SPI_MSB, SPI_INTERRUPT, SPI_SLAVE);
+}
+
+// called when the button pushed and pin INT0 goes from 1 to 0
+ISR(INT0_vect)
+{
+  send_message();
+  _delay_ms(500); // 'debounce'
+}
+
+// parse the data received from the other device
+// currently just knows about the FLASH_LED_COMMAND
+void parse_message()
+{
+  switch(incoming[0]) {
+  case FLASH_LED_COMMAND:
+    flash_led(incoming[1]);
+    break;
+  default:
+    flash_led(20);
+  }
+}
+
+// called by the SPI system when there is data ready.
+// Just store the incoming data in a buffer, when we receive a
+// terminating byte (0x00) call parse_message to process the data received
+ISR(SPI_STC_vect)
+{
+  incoming[received++] = received_from_spi(0x00);
+  if (received >= BUFSIZE || incoming[received-1] == 0x00) {
+    parse_message();
+    received = 0;
+  }
+}
+ 
+int main(void)
+{
+  // make sure other device is unselected (pin is HIGH) and setup spi
+  DESELECT_OTHER;
+  DDRB |= (1<<OTHER_SELECT_PIN);
+  setup_spi(SPI_MODE_1, SPI_MSB, SPI_INTERRUPT, SPI_SLAVE);
+  
+  // raise interrupt when the button is pushed and INT0 pin goes 
+  // from 1 to 0 (pin PD0 at AT90usbXXX, pin PD2 on ATmegaXXX, 
+  // arduino pin 2)). The code in ISR(INT0_vect) above will be called
+  EICRB = (1<<ISC01) | (0<<ISC00);
+  EIMSK |= (1<<INT0);
+  sei();
+
+  // flash LED at start to indicate were ready
+  flash_led(1);
+
+  while (1); // do nothing
+}
@@ -0,0 +1,99 @@
+/* 
+ * Copyright (c) 2009 Andrew Smallbone <andrew@rocketnumbernine.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <avr/sleep.h>
+#include <util/delay.h>
+
+#include <ds1305.h>
+
+// following two methods required by DS1305 library to select/deselect device
+void select_ds1305(void)
+{
+  PORTD |= (1<<PD4);
+}
+
+void deselect_ds1305(void)
+{
+  PORTD &= ~(1<<PD4);
+}
+
+// flash led that's connected to pin PD1
+void flash_led(void)
+{
+  DDRD |= (1<<PD1);
+  for (int i=0; i<10; i++) {
+    PORTD ^= (1<<PD1);
+    _delay_ms(50);
+  }
+}
+
+// called when pin INT0 goes from 1 to 0
+ISR(INT0_vect)
+{
+  // get alarm value to clear alarm interrupt flag on DS1305
+  DS1305_DATETIME alarm;
+  get_alarm0(&alarm);
+  flash_led();
+}
+
+int main(void)
+{
+  // flash LED at start to indicate were about to start
+  flash_led();
+  flash_led();
+  
+  // pin used to enable DS1305
+  DDRD = (1<<PD4);
+  
+  // Make sure ADC is unselected and setup spi
+  deselect_ds1305();
+  setup_spi(SPI_MODE_1, SPI_MSB, SPI_NO_INTERRUPT, SPI_MSTR_CLK16);
+  set_control(0);
+
+  // set current date/time to Thursday 06/05/09 20:32:30
+  DS1305_DATETIME current = {0x30, 0x32, 0x20, 0x05, 0x06, 0x05, 0x09};
+  set_time(&current);
+  
+  // change the value of alarm to the required time/granularity:
+  // raise alarm every day (at 20:32:00):
+  // DS1305_DATETIME alarm = {0x00, 0x32, 0x20, 0x00 | DS1305_ALARM_SET};
+  // raise alarm every minute (when seconds = 00):
+  // DS1305_DATETIME alarm = {0x00, 0x32 | DS1305_ALARM_SET,
+  //		   0x20 | DS1305_ALARM_SET, 0x05 | DS1305_ALARM_SET};
+  // raise alarm every second:
+  DS1305_DATETIME alarm = {0x55 | DS1305_ALARM_SET, 0x32 | DS1305_ALARM_SET,
+  			   0x20 | DS1305_ALARM_SET, 0x05 | DS1305_ALARM_SET};
+  set_alarm0(&alarm);
+  // turn on timer and make alarm0 lower INT0 pin when alarm is triggered
+  set_control(DS1305_EOSC | DS1305_INTCN | DS1305_AIE0);
+
+  // raise interrupt when INT0 pin falls (pin PD0 at AT90usbXXX, pin PD2 on ATmegaXXX (arduino pin 2))
+  // the code in ISR(INT0_vect) above will be called
+  EICRA = (1<<ISC01) | (0<<ISC00);
+  // enable interrupts
+  EIMSK = (1<<INT0);
+  sei();
+
+  while(1);
+}
@@ -0,0 +1,151 @@
+/* 
+ * Copyright (c) 2009 Andrew Smallbone <andrew@rocketnumbernine.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "spi.h"
+
+#ifdef __cplusplus
+extern "C"{
+#endif
+
+#ifdef __ARDUINO__
+#include <wiring.h>
+#endif
+
+#ifndef SPI_SOFT_DRIVER
+
+// hardware driver
+
+void setup_spi(uint8_t mode, int dord, int interrupt, uint8_t clock)
+{
+  // specify pin directions for SPI pins on port B
+  if (clock == SPI_SLAVE) { // if slave SS and SCK is input
+    DDRB &= ~(1<<SPI_MOSI_PIN); // input
+    DDRB |= (1<<SPI_MISO_PIN); // output
+    DDRB &= ~(1<<SPI_SS_PIN); // input
+    DDRB &= ~(1<<SPI_SCK_PIN);// input
+  } else {
+    DDRB |= (1<<SPI_MOSI_PIN); // output
+    DDRB &= ~(1<<SPI_MISO_PIN); // input
+    DDRB |= (1<<SPI_SCK_PIN);// output
+    DDRB |= (1<<SPI_SS_PIN);// output
+  }
+  SPCR = ((interrupt ? 1 : 0)<<SPIE) // interrupt enabled
+    | (1<<SPE) // enable SPI
+    | (dord<<DORD) // LSB or MSB
+    | (((clock != SPI_SLAVE) ? 1 : 0) <<MSTR) // Slave or Master
+    | (((mode & 0x02) == 2) << CPOL) // clock timing mode CPOL
+    | (((mode & 0x01)) << CPHA) // clock timing mode CPHA
+    | (((clock & 0x02) == 2) << SPR1) // cpu clock divisor SPR1
+    | ((clock & 0x01) << SPR0); // cpu clock divisor SPR0
+  SPSR = (((clock & 0x04) == 4) << SPI2X); // clock divisor SPI2X
+}
+
+void disable_spi()
+{
+  SPCR = 0;
+}
+
+uint8_t send_spi(uint8_t out)
+{
+  SPDR = out;
+  while (!(SPSR & (1<<SPIF)));
+  return SPDR;
+}
+
+uint8_t received_from_spi(uint8_t data)
+{
+  SPDR = data;
+  return SPDR;
+}
+
+#else
+
+// software driver
+void setup_spi(uint8_t mode, int dord, int interrupt, uint8_t clock)
+{
+	if(mode) if(dord) if (interrupt) if(clock) {}
+	// specify pin directions for SPI pins on port B
+	if (clock == SPI_SLAVE) { // if slave SS and SCK is input
+		SPI_DDR &= ~(1<<SPI_MOSI_PIN); // input
+		SPI_DDR |= (1<<SPI_MISO_PIN); // output
+//		SPI_DDR &= ~(1<<SPI_SS_PIN); // input
+		SPI_DDR &= ~(1<<SPI_SCK_PIN);// input
+	} else {
+		SPI_DDR |= (1<<SPI_MOSI_PIN); // output
+		SPI_DDR &= ~(1<<SPI_MISO_PIN); // input
+		SPI_DDR |= (1<<SPI_SCK_PIN);// output
+//		SPI_DDR |= (1<<SPI_SS_PIN);// output
+	}
+}
+
+void disable_spi()
+{
+}
+
+uint8_t send_spi(uint8_t tx)
+{
+    uint8_t i = 0;
+    uint8_t rx = 0;
+
+	SPI_PORT &= ~(1 << SPI_SCK_PIN);
+_delay_us(50);
+
+    //nrf24_sck_digitalWrite(LOW);
+
+    for(i=0;i<8;i++)
+    {
+	    if(tx & (1<<(7-i)))
+	    {
+			SPI_PORT |= (1 << SPI_MOSI_PIN);
+		    //nrf24_mosi_digitalWrite(HIGH);
+	    }
+	    else
+	    {
+			SPI_PORT &= ~(1 << SPI_MOSI_PIN);
+		    //nrf24_mosi_digitalWrite(LOW);
+	    }
+
+		SPI_PORT |= (1 << SPI_SCK_PIN);
+	    //nrf24_sck_digitalWrite(HIGH);
+_delay_us(50);
+
+	    rx = rx << 1;
+	    if(SPI_PIN & (1 << SPI_MISO_PIN))
+	    //if(nrf24_miso_digitalRead())
+	    {
+		    rx |= 0x01;
+	    }
+
+	    //nrf24_sck_digitalWrite(LOW);
+		SPI_PORT &= ~(1 << SPI_SCK_PIN);
+
+    }
+_delay_us(50);
+
+    return rx;
+}
+
+//uint8_t received_from_spi(uint8_t data)
+//{
+//}
+
+#endif
@@ -0,0 +1,101 @@
+/* 
+ * Copyright (c) 2009 Andrew Smallbone <andrew@rocketnumbernine.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef _spi_h__
+#define _spi_h__
+
+#include <avr/io.h>
+
+#ifdef __cplusplus
+extern "C"{
+#endif
+
+
+// create alias for the different SPI chip pins - code assumes all on port B
+#if (defined(__AVR_AT90USB82__) || defined(__AVR_AT90USB162__))
+ #define SPI_SS_PIN PORTB0
+ #define SPI_SCK_PIN PORTB1
+ #define SPI_MOSI_PIN PORTB2
+ #define SPI_MISO_PIN PORTB3
+#elif (defined(__AVR_ATmega48__) || defined(_AVR_ATmega88__) || defined(__AVR_ATmega168__) || defined(__AVR_ATmega328__) || defined(__AVR_ATmega328P__)) \
+	|| defined(__AVR_ATmega168PA__) || defined(__AVR_ATmega8A__)
+ #define SPI_PORT	PORTB
+ #define SPI_PIN	PINB
+ #define SPI_DDR	DDRB
+ #define SPI_SS_PIN PORTB2
+ #define SPI_SCK_PIN PORTB5
+ #define SPI_MOSI_PIN PORTB3
+ #define SPI_MISO_PIN PORTB4
+#else
+ #error unknown processor - add to spi.h
+#endif
+
+// SPI clock modes
+#define SPI_MODE_0 0x00 /* Sample (Rising) Setup (Falling) CPOL=0, CPHA=0 */
+#define SPI_MODE_1 0x01 /* Setup (Rising) Sample (Falling) CPOL=0, CPHA=1 */
+#define SPI_MODE_2 0x02 /* Sample (Falling) Setup (Rising) CPOL=1, CPHA=0 */
+#define SPI_MODE_3 0x03 /* Setup (Falling) Sample (Rising) CPOL=1, CPHA=1 */
+
+// data direction
+#define SPI_LSB 1 /* send least significant bit (bit 0) first */
+#define SPI_MSB 0 /* send most significant bit (bit 7) first */
+
+// whether to raise interrupt when data received (SPIF bit received)
+#define SPI_NO_INTERRUPT 0
+#define SPI_INTERRUPT 1
+
+// slave or master with clock diviser
+#define SPI_SLAVE 0xF0
+#define SPI_MSTR_CLK4 0x00 /* chip clock/4 */
+#define SPI_MSTR_CLK16 0x01 /* chip clock/16 */
+#define SPI_MSTR_CLK64 0x02 /* chip clock/64 */
+#define SPI_MSTR_CLK128 0x03 /* chip clock/128 */
+#define SPI_MSTR_CLK2 0x04 /* chip clock/2 */
+#define SPI_MSTR_CLK8 0x05 /* chip clock/8 */
+#define SPI_MSTR_CLK32 0x06 /* chip clock/32 */
+
+
+
+// setup spi
+void setup_spi(uint8_t mode,   // timing mode SPI_MODE[0-4]
+	       int dord,             // data direction SPI_LSB|SPI_MSB
+	       int interrupt,        // whether to raise interrupt on recieve
+	       uint8_t clock); // clock diviser
+
+// disable spi
+void disable_spi(void);
+
+// send and receive a byte of data (master mode)
+uint8_t send_spi(uint8_t out);
+
+// receive the byte of data waiting on the SPI buffer and
+// set the next byte to transfer - for use in slave mode
+// when interrupts are enabled.
+uint8_t received_from_spi(uint8_t out);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#include "spi.c"
+
+#endif
+