[rawe]’s simplification of this is to get rid of the transistors and just plop a single 1N4148 diode in there. This would of course be useless without the software to communicate with 1-Wire ...

Instead of buying a thermocouple or using an LM75 or similar temperature-measurement IC, [acidbourbon] uses a bog-standard 1n4148 diode. The current passed through a diode, at a given voltage ...