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Ask HN: Most interesting tech you built for just yourself?

1901 points l2silver | 3 comments | 27 Apr 23 15:04 UTC | HN request time: 0.652s | source

Maybe you've created your own AR program for wearables that shows the definition of a word when you highlight it IRL, or you've built a personal calendar app for your family to display on a monitor in the kitchen. Whatever it is, I'd love to hear it.
1. nielsole ◴[28 Apr 23 18:18 UTC] No.35745109[source]▶
At the beginning of COVID i switched to weekly shopping and realized that it takes a significant time to inventarize the storage to make sure I make it through the week.

I built a storage shelf that self-inventorizes based on strain gauges. Through the change in weight distribution it can determine the weight and 2D location of the item added or removed. LED strips give immediate feedback. https://www.niels-ole.com/arduino/iot/2021/03/21/storage-sys...

I used this to automatically add the items consumed throughout the week to my shopping list.

I only ever built a single shelf board (subsequent boards had issues) and I never fully implemented the advanced usability features of adding new items for the first time and automatically determining good places for them, but it was a very fun project.

replies(1): >>35746185 #
2. _qua ◴[28 Apr 23 19:45 UTC] No.35746185[source]▶
So does each type of item have its own designated spot on the shelf or is it figuring out the item identity based on weight?
replies(1): >>35746645 #
3. nielsole ◴[28 Apr 23 20:24 UTC] No.35746645[source]▶
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.