Each item type had its area in a database with x_start, x_end, y_start, y_end and weight. These areas could overlap though. I had an error function that picked the most likely option: https://gitlab.com/nielsole/logistics-board/-/blob/master/se...

Manually adding areas for all items would not have been feasible(>100 different product types with sometimes multiple SKUs from different brand for the same product type), so my idea was to add a hand-scanner and when a barcode gets scanned, it checks if it knows the product. If it doesn't, it would tell you to put it in a special weighing position. After wheighing it would light up all the boards in accordance of how well the item could be placed there. This could have taken into account the total weight of the board and the likelihood for the item weight to be mistaken for another product already on the shelf.

In the end I gave up before getting these usability improvements in.