USBtinyThermometer is a project mainly written in C and C++, based on the GPL-3.0 license.
Thermometer on ATtiny44 and DS18B20
Simple thermometer based on ATtiny44 MCU and DS18B20 thermal sensor.
Software USB interface from project USBtiny.
Hardware: ATtiny44, DS18B20
Firmware: C, USBtiny
Software: C++
Photos here. Video here.