I understand -
- in Your system default minimum distance between objects is
120 mm (47+24+24) and You want to minimize to 4 mm. But how objects are oriented - with shortest side among movement direction (this is fastest case)?
If distance between objects is >= 120 mm You dont need to
read simultaneously - You store R, then G and when B arrives
You combine all .
If distance is <120 mm You will have B signal from one object
G signal from other (or from no object) and R signal from another object(or from no object). You have 2 choices
- to use 3 sensors at one point and read them simultaneously
- to analize info from each sensor, count objects for every sensor, store data using tree pointers. When B-signal for object N is ready (last sensor) You allready have R&G signal data for this object. Set can be handled for object N.
In both variants trigger can be omited from system.
If shortest side (4 mm) of object is visible by sensor then You valid signal is about 9.5 msec duration and 9.5 msec dark time (4 mm gap). I will aim to get
response under 3..4 msec - better is 1 msec. Then each 3 msec You can have adequate info for each channel, using one counter/timer and multiplexer. Here may be problem with freqwency range of sensor.