3 ms·
There are encoded signals used by these things: https://en.wikipedia.org/wiki/Portable_People_Meter https://en.wikipedia.org/wiki/Portable_People_Meter
by nitrogen 6y ago
There are encoded signals used by these things: https://en.wikipedia.org/wiki/Portable_People_Meter https://en.wikipedia.org/wiki/Portable_People_Meter