This book details a number of projects for the Raspberry Pi GPIO and provides links to detailed instructions with downloadable Python code. These are great for students and those wanting to interface the Raspberry Pi to the outside world. Project 11 - Using the Raspberry Pi to measure temperature Project 12 - Writing to a serial LCD with the Raspberry Pi Project 13 - Using the Raspberry Pi to measure battery voltage Project 14 - Using the Raspberry Pi to measure current Project 15 - Reading a keypad with the Raspberry Pi