added some stuff

DS1621/DS1621.ino

@@ -0,0 +1,43 @@
+#include <Wire.h>
+
+#define DEV_ID 0x90 >> 1                        // shift required by wire.h
+
+
+void setup()
+{
+    Serial.begin(9600);
+
+    Wire.begin();
+    Wire.beginTransmission(DEV_ID);             // connect to DS1621 (#0)
+    Wire.write(0xAC);                            // Access Config
+    Wire.write(0x02);                            // set for continuous conversion
+    Wire.beginTransmission(DEV_ID);             // restart
+    Wire.write(0xEE);                            // start conversions
+    Wire.endTransmission();
+}
+
+
+void loop()
+{
+    int8_t firstByte;
+    int8_t secondByte;
+    float temp = 0;
+
+    delay(1000);                                // give time for measurement
+
+    Wire.beginTransmission(DEV_ID);
+    Wire.write(0xAA);                            // read temperature command
+    Wire.endTransmission();
+    Wire.requestFrom(DEV_ID, 2);    // request two bytes from DS1621 (0.5 deg. resolution)
+
+    firstByte = Wire.read();           // get first byte
+    secondByte = Wire.read();    // get second byte
+
+    temp = firstByte;
+
+    if (secondByte)             // if there is a 0.5 deg difference
+        temp += 0.5;
+
+    Serial.println(temp);
+
+}

PF575_I2C_8LED_BLINK/PF575_I2C_8LED_BLINK.ino

@@ -0,0 +1,75 @@
+#include <Wire.h>
+
+/** 
+ *  Arduino PF575/PCF8575 I2C I/O port exapander LED blink example
+ *  
+ *  Setup:
+ *  
+ *  1. Connect A0, A1 and A2 to GND to set the address to 0x20.
+ *  2. Connect SDL and SCL to the Arduino's I2C bus.
+ *  3. Connect a LED to the P0 port of the I2C exapander.
+ *     In my setup I am using a PNP Transistor connected to 5V unsing 
+ *     an resistor, the LED and the Arduino to make sure the LED gets
+ *     a current from Vcc and not from the I2C exapander port.
+ *  
+ *  This code is trying to explain how it works as simple as possible.
+ *  More detailed examples are found on the web. Search for pcf8575 and
+ *  you will find what you want.
+*/
+
+// Set I2C address
+int address = 0x20;
+
+void setup(){ 
+  Wire.begin();
+  pf575_write(word(B11111111,B11111111));
+  delay(200);
+  pf575_write(word(B00000000,B11111111));
+  delay(200);
+  pf575_write(word(B11111111,B11111111));
+  delay(200);
+  pf575_write(word(B00000000,B11111111));
+  delay(200);
+  pf575_write(word(B11111111,B11111111));
+  delay(1000);
+} 
+
+void loop(){
+  int dTime = 150;
+  pf575_write(word(B11111110,B11111111));
+  delay(dTime);
+  pf575_write(word(B11111101,B11111111));
+  delay(dTime);
+  pf575_write(word(B11111011,B11111111));
+  delay(dTime);
+  pf575_write(word(B11110111,B11111111));
+  delay(dTime);
+  pf575_write(word(B11101111,B11111111));
+  delay(dTime);
+  pf575_write(word(B11011111,B11111111));
+  delay(dTime);
+  pf575_write(word(B10111111,B11111111));
+  delay(dTime);
+  pf575_write(word(B01111111,B11111111));
+  delay(dTime);
+  pf575_write(word(B10111111,B11111111));
+  delay(dTime);
+  pf575_write(word(B11011111,B11111111));
+  delay(dTime);
+  pf575_write(word(B11101111,B11111111));
+  delay(dTime);
+  pf575_write(word(B11110111,B11111111));
+  delay(dTime);
+  pf575_write(word(B11111011,B11111111));
+  delay(dTime);
+  pf575_write(word(B11111101,B11111111));
+  delay(dTime);
+} 
+
+// Function for writing two Bytes to the I2C expander device
+void pf575_write(uint16_t data) {
+  Wire.beginTransmission(address);
+  Wire.write(highByte(data));
+  Wire.write(lowByte(data));
+  Wire.endTransmission();
+}