I removed an LDR from an old analog television. Can I use it as a sensor in an application with a microcontroller, such as Arduino?
When using a component it does not matter the technology or age as long as it is good. An old LDR, like other sensors such as an NTC or a phototransistor, does not matter if they are old or new, they work the same way and can be used in any project if their characteristics match. Thus, old LDRs taken from old televisions (where they were used in automatic brightness control) or automatic light switches can be perfectly used in modern circuits with microcontrollers, for example.
