ds1620 digital thermometer question

[system]

I'm trying to make this device work: Mixed-signal and digital signal processing ICs | Analog Devices

The wiring was easy, but I don't understand how to make the sketch work. It requires a library and I never used one before and it seems I'm doing something wrong. I would appreciate your kind help!

Sketch: http://wiki.thinkhole.org/ds1620
Library required: GitHub - jpmulligan/Arduino-DS1620: Arduino DS1620 library to interface an Arduino with the Dallas Semiconductor DS1620 Digital Thermometer and Thermostat

1. I quit Arduino

2. I unzipped the library into ~/Documents/Arduino/libraries/DS1620/ (it's a Mac, see attachment)

3. I put the example sketch into ~/Documents/Arduino/ds1620_example/ds1620_example.pde

4. I open the sketch with Arduino app and when I try to verify it gives me this error.

It highlighst this part in the code:

// Call DS1620 constructor using pin variables
DS1620 d = DS1620(dq, clk, rst);

And gives this error below:

ds1620_example.pde:50:20: error: DS1620.h: No such file or directory
ds1620_example:58: error: 'DS1620' does not name a type
ds1620_example.pde: In function 'void setup()':
ds1620_example:67: error: 'd' was not declared in this scope
ds1620_example.pde: In function 'void loop()':
ds1620_example:88: error: 'd' was not declared in this scope

[MarkT]

DS1620.h is not ds1620.h

[robtillaart]

A quick look at the library shows that the sensor does measure in 0.5C steps, but the lib rounds this to 1 degree steps.
I assume this is done to keep the math integer only ==> faster