You’re right, i didn’t consider this 
So piezo might be back again. Probably for the next gen
I improved again the prototype, now using the duplo from my sons (see picture).
As i need a quite big whole for the bags, 4 IR sensors are not enough. I’ll need to put 6.
But the good thing is that only 3 sensors need to be connected to the arduino (the ones placed on the left). The 3 on the right are only there to create the break beam, and don’t need to be connected (so i don’t need the small carton to hide anymore).
I also put a delay of 150 ms for each sensor, so that the 3 sensors are not processed at the same time. I’ll need to test in real conditions to see if i need to extend this delay or not.
As i’m missing 2 IR sensors, i ordered new ones. So next post in a few days
See you,
