process.txt

for vehicles:

IR sensor is triggered
we verify that the trigger is a car 
how? we calibrate the motion sensor sensitivity
if it is a car, we shut down (ignore) the motion sensor for 5 minutes


startup process:

microcontroller
python script first
then server

we need an efficient way of detecting whether a vehicle is present or not in the case that the motion sensor keeps going off,
the caveman method is to process the image taken everytime the sensor reports activity
however, when a car truly arrives, the sensor may keep going off for a while and this is what we need to combat
what we can do, before sending the order to open the gate to the microcontroller, we can:
cache entries with time
if vehicle is present we compare it to the last vehicle which was present and do a delta time
we set a delta limit of about umm (3 minutes)
if the sensor keeps reporting that a car is available we compare delta time to the delta limit
if delta time > delta limit then we consider that a new arrival and proceed to open the gate, otherwise we pass and assume it has been handled already


so our logic begins in app.py 
specifically after the plate number is extracted

the technicals:
ok, so we need a way to do this:
record the time any vehicle comes, along with the number plate of that same vehicle
one approach is to use the redis db, this is an in memory db which is lost when the computer restarts (i think)
ok time to learn REDIS (ask ChatGPT)