Methods to get a number of people in a room to TD

Hi, I’m designing an installation for a bar and curious to see if it might be possible to get a live reading of the number of people in the bar to Touchdesigner, to be used to drive certain CHOP elements.

The bar has a bouncer who uses a manual tally counter to keep track of the number of people in the room.

Do you think there might be some similar digital tally device that can transmit a number to a touchdesigner PC in the same room? Alternatively, could be there another way to get the number of people in the room to TD? I think some kind of manual count is likely the only way though?

you could maybe use a phone with something like touchOSC on it, then have a +& - button on it and use that as a digital tally device. it can send OSC out to TD which could be used to increment and decrement a value recieved by TD over OSC.